Polypyrrole adhesion to indium–tin oxide electrodes was improved by adding pre-hydrolyzed alkoxysilanes to the electrodeposition media. The pyrrole oxidation and film growth rates were studied by potentiostatic polymerization in acidic media. The morphology and thickness of the films were studied by contact profilometry and surface-scanning electron microscopy. The bulk and surface semiquantitative chemical composition was studied by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Finally, the adhesion was studied by scotch-tape adhesion test, where both alkoxysilanes showed a significant improvement in adhesion. We proposed a hypothesis for the improvement in adhesion, that involves the formation of siloxane material as well as in situ surface modification of the transparent metal oxide electrode. Full article

The use of polymers in silicon chips is of great importance for the development of microelectronic and biomedical industries. In this study, new silane-containing polymers, called OSTE-AS polymers, were developed based on off-stoichiometry thiol–ene polymers. These polymers can bond to silicon wafers without pretreatment of the surface by an adhesive. Silane groups were included in the polymer using allylsilanes, with the thiol monomer as the target of modification. The polymer composition was optimized to provide the maximum hardness, the maximum tensile strength, and good bonding with the silicon wafers. The Young’s modulus, wettability, dielectric constant, optical transparency, TGA and DSC curves, and the chemical resistance of the optimized OSTE-AS polymer were studied. Thin OSTE-AS polymer layers were obtained on silicon wafers via centrifugation. The possibility of creating microfluidic systems based on OSTE-AS polymers and silicon wafers was demonstrated. Full article

Fluorosilicone rubber (F-LSR) is a promising material that can be applied in various cutting-edge industries. However, the slightly lower thermal resistance of F-LSR compared with that of conventional PDMS is difficult to overcome by applying nonreactive conventional fillers that readily agglomerate owing to their incompatible structure. Polyhedral oligomeric silsesquioxane with vinyl groups (POSS-V) is a suitable material that may satisfy this requirement. Herein, F-LSR-POSS was prepared using POSS-V as a chemical crosslinking agent chemically bonded with F-LSR through hydrosilylation. All F-LSR-POSSs were successfully prepared and most of the POSS-Vs were uniformly dispersed in the F-LSR-POSSs, as confirmed by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (¹H-NMR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements. The mechanical strength and crosslinking density of the F-LSR-POSSs were determined using a universal testing machine (UTM) and dynamic mechanical analysis (DMA), respectively. Finally, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements confirmed that the low-temperature thermal properties were maintained, and the heat resistance was significantly improved compared with conventional F-LSR. Eventually, the poor heat resistance of the F-LSR was overcome with three-dimensional high-density crosslinking by introducing POSS-V as a chemical crosslinking agent, thereby expanding the potential fluorosilicone applications. Full article

The residual stress phenomenon in the injection process of an optical lens affects the quality of optical components, and the refractive error caused by geometric errors is the most serious, followed by the degradation of the accuracy and function of optical components. It is very important to ensure that the lens geometry remains intact and the refractive index is low. Therefore, a parameter design method for an optical liquid silicon injection molding was proposed in this study. Wavelet analysis was applied to the noise reduction and feature extraction of the cavity pressure/pressure retaining curve of the injection molding machine, and multiple identifiable performance evaluation methods were used to identify and optimize the parameters of the molding process. Taking an automotive LED lens as an example, Moldex3D simulation software was used to simulate the molding of an LED lens made of LSR material, and two key injection molding factors, melt temperature and V/P switching point, were analyzed and optimized. In this paper, the transmittance and volume shrinkage of LED lenses are taken as quality indexes, and parameters are optimized by setting different V/P switching points and melt temperature schemes. The experimental results show that the residual stress is negatively correlated with transmittance, and the higher the residual stress, the lower the transmittance. Under the optimum process parameters generated by this method, the residual stress of plastic parts is significantly optimized, and the optimization rate is above 15%. In addition, when the V/P switching point is 98 and the melt temperature is 30 °C, the product quality is the best, the volume shrinkage rate is the smallest, and the size is 2.895%, which also means that the carbon emissions are the lowest. Full article

In the search for solution-processable TADF materials as a light emitting layer for OLED devices, polymers have attracted considerable attention due to their better thermal and morphological properties in the film state with respect to small molecules. In this work, a new polymer (p-TPS-DMAC-TRZ) with thermally activated delayed fluorescence (TADF) light-emitting characteristics was prepared from a conjugation-break unit (TPS) and a well-known TADF core (DAMC-TRZ). This material was designed to preserve the photophysical properties of DAMC-TRZ, while improving other properties, such as thermal stability, promoted by its polymerization with a TPS core. Along with excellent solubility in common organic solvents such as toluene, chloroform and THF, the polymer (M_n = 9500; M_w = 15200) showed high thermal stability (TDT_5% = 481 °C), and a T_g value of 265 °C, parameters higher than the reference small molecule DMAC-TRZ (TDT_5% = 305 °C; T_g = 91 °C). The photoluminescence maximum of the polymer was centered at 508 nm in the solid state, showing a low redshift compared to DMAC-TRZ (500 nm), while also showing a redshift in solution with solvents of increasing polarity. Time-resolved photoluminescence of p-TPS-DMAC-TRZ at 298 K, showed considerable delayed emission in solid state, with two relatively long lifetimes, 0.290 s (0.14) and 2.06 s (0.50), and a short lifetime of 23.6 ns, while at 77 K, the delayed emission was considerably quenched, and two lifetimes in total were observed, 24.6 ns (0.80) and 180 ns (0.20), which was expected from the slower RISC process at lower temperatures, decreasing the efficiency of the delayed emission and demonstrating that p-TPS-DMAC-TRZ has a TADF emission. This is in agreement with room temperature TRPL measurements in solution, where a decrease in both lifetime and delayed contribution to total photoluminescence was observed when oxygen was present. The PLQY of the mCP blend films with 1% p-TPS-DMAC-DMAC-TRZ as a dopant was determined to be equal to 0.62, while in the pure film, it was equal to 0.29, which is lower than that observed for DMAC-TRZ (0.81). Cyclic voltammetry experiments showed similarities between p-TPS-DMAC-TRZ and DAMC-TRZ with HOMO and LUMO energies of −5.14 eV and −2.76 eV, respectively, establishing an electrochemical bandgap value of 2.38 eV. The thin film morphology of p-TPS-DMAC-TRZ and DMAC-TRZ was compared by AFM and FE-SEM, and the results showed that p-TPS-DMAC-TRZ has a smoother surface with fewer defects, such as aggregations. These results show that the design strategy succeeded in improving the thermal and morphological properties in the polymeric material compared to the reference small molecule, while the photophysical properties were mostly maintained, except for the PLQY determined in the pure films. Still, these results show that p-TPS-DMAC-TRZ is a good candidate for use as a light-emitting layer in OLED devices, especially when used as a host-guest mixture in suitable materials such as mCP. Full article

General information concerning different kinds of chemical additives used in the textile industry has been described in this paper. The properties and applications of organofunctional silanes and polysiloxanes (silicones) for chemical and physical modifications of textile materials have been reviewed, with a focus on silicone softeners, silane, and silicones-based superhydrophobic finishes and coatings on textiles composed of silicone elastomers and rubbers. The properties of textile materials modified with silanes and silicones and their practical and potential applications, mainly in the textile industry, have been discussed. Full article

To explore the influence mechanisms of polyurethane soft segments on modified silicone coatings, a series of modified coatings was prepared by introducing different contents of hydroxypropyl-terminated polydimethylsiloxane (PDMS2200) into the soft segment of polyurethane. ATR-FTIR, NMR, CLSM, AFM, contact angle measurement, the tensile test, bacterial adhesion, and the benthic diatom adhesion test were used to investigate the structure, morphology, roughness, degree of microphase separation, surface energy, tensile properties, and antifouling properties of the modified coatings. The results show that PDMS2200 could aggravate the microphase separation of the modified coatings, increase the surface-free energy, and reduce its elastic modulus; when the microphase separation exceeded a certain degree, increasing PDMS2200 would decrease the tensile properties. The PED-TDI polyurethane-modified silicone coating prepared with the formula of PU-Si17 had the best tensile properties and antifouling properties among all modified coatings. Full article

Small additions of nanofiber materials make it possible to change the properties of polymers. However, the uniformity of the additive distribution and the strength of its bond with the polymer matrix are determined by the surface of the nanofibers. Silanes, in particular, allow you to customize the surface for better interaction with the matrix. The aim of our work is to study an approach to silanization of nanofibers of aluminum oxide to obtain a perfect interface between the additive and the matrix. The presence of target silanes on the surface of nanofibers was shown by XPS methods. The presence of functional groups on the surface of nanofibers was also shown by the methods of simultaneous thermal analysis, and the stoichiometry of functional groups with respect to the initial hydroxyl groups was studied. The number of functional groups precipitated from silanes is close to the number of the initial hydroxyl groups, which indicates a high uniformity of the coating in the proposed method of silanization. The presented technology for silanizing alumina nanofibers is an important approach to the subsequent use of this additive in various polymer matrices. Full article

This study reports on a series of crosslinked poly(arylene ether)s with POSS in the main chain. The fluorinated and terminated poly(arylene ether)s were first synthesized by the nucleophilic reaction of diphenol POSS and decafluorodiphenyl monomers, including decafluorobiphenyl, decaflurobenzophenone, and decafluorodiphenyl sulfone. They were then reacted with 3-hydroxyphenyl acetylene to produce phenylacetylene-terminated poly(arylene ether)s. The polymers were of excellent processability. When heated to a high temperature, the polymers converted into a crosslinked network, exhibiting a low range of dielectric constant from 2.17 to 2.58 at 1 HMz, strong resistance against chemical solutions, low dielectric losses, and good thermal and hydrophobic properties. Full article

Degradation of silicon rubber due to heat and humidity affect its performance in outdoor applications. To analyze the effects of high temperature and humidity on room temperature vulcanized (RTV) silicone rubber (SiR) and its composites, this study was performed. Five different sample compositions including neat silicone rubber (nSiR), microcomposites (15 wt% silica(SMC 15% SiO₂) and 15 wt% ATH(SMC 15% ATH), nanocomposite (2.5 wt% silica(SNC 2.5% SiO₂) and hybrid composite (10 wt% micro alumina trihydrate with 2 wt% nano silica(SMNC 10% ATH 2% SiO₂) were prepared and subjected to 70 ˚C temperature and 80% relative humidity in an environmental chamber for 120 h. Contact angle, optical microscopy and Fourier transform infrared (FTIR) spectroscopy were employed to analyze the recovery properties before and after applying stresses. Different trends of degradation and recovery were observed for different concentrations of composites. Addition of fillers improved the overall performance of composites and SMC 15% ATH composite performed better than other composites. For high temperature and humidity, the ATH-based microcomposite was recommended over silica due to its superior thermal retardation properties of ATH. It has been proved that ATH filler is able to withstand high temperature and humidity. Full article

New copolymers based on vinylidene fluoride (VDF) and 2,3,3,3-tetrafluoroprop-1-ene (1234yf) were synthesized by organometallic-mediated radical copolymerization (OMRcP) using the combination of bis(tert-butylcyclohexyl) peroxydicarbonate initiator and bis(acetylacetonato)cobalt(II), (Co(acac)₂) as a controlling agent. Kinetics studies of the copolymerization of the fluoroalkenes copolymers were monitored by GPC and ¹⁹F NMR with molar masses up to 12,200 g/mol and dispersities (Đ) ranging from 1.33 to 1.47. Such an OMRcP behaves as a controlled copolymerization, evidenced by the molar mass of the resulting copolymer-monomer conversion linear relationship. The reactivity ratios, r_i, of both comonomers were determined by using the Fineman-Ross and Kelen-Tüdos fitting model leading to r_VDF = 0.384 ± 0.013 and r_1234yf = 2.147 ± 0.129 at 60 °C, showing that a lower reactivity of VDF integrated in the copolymer to a greater extent leads to the production of gradient or pseudo-diblock copolymers. In addition, the Q (0.03) and e (0.06 and 0.94) parameters were assessed, as well as the dyad statistic distributions and mean square sequence lengths of PVDF and P1234yf. Full article

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film. Full article

The increasing demand for polymer composites with novel or improved properties requires novel fillers. To meet the challenges posed, nanofillers such as graphene, carbon nanotubes, and titanium dioxide (TiO₂) have been used. In the present work, few-layer graphene (FLG) and iron oxide (Fe₃O₄) or TiO₂ were used as fillers in a room-temperature-vulcanized (RTV) silicone rubber (SR) matrix. Composites were prepared by mixing RTV-SR with nanofillers and then kept for vulcanization at room temperature for 24 h. The RTV-SR composites obtained were characterized with respect to their mechanical, actuation, and magnetic properties. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to investigate the composite raw materials and finished composites, and X-ray photoelectron spectroscopy (XPS) analysis was used to study composite surface elemental compositions. Results showed that mechanical properties were improved by adding fillers, and actuation displacements were dependent on the type of nanofiller used and the applied voltage. Magnetic stress-relaxation also increased with filler amount and stress-relaxation rates decreased when a magnetic field was applied parallel to the deformation axes. Thus, this study showed that the inclusion of iron oxide (Fe₃O₄) or TiO₂ fillers in RTV-SR improves mechanical, actuation, and magnetic properties. Full article

Hybrid silica xerogels combine the properties of organic and inorganic components in the same material, making them highly promising and versatile candidates for multiple applications. They can be tailored for specific purposes through chemical modifications, and the consequent changes in their structures warrant in-depth investigation. We describe the synthesis of three new series of organochlorinated xerogels prepared by co-condensation of tetraethyl orthosilicate (TEOS) and chloroalkyltriethoxysilane (ClRTEOS; R = methyl [M], ethyl [E], or propyl [P]) at different molar ratios. The influence of the precursors on the morphological and textural properties of the xerogels was studied using ²⁹Si NMR (Nuclear Magnetic Resonance), FTIR (Fourier-Transform Infrared Spectroscopy), N₂, and CO₂ adsorption, XRD (X-ray Diffraction), and FE-SEM (Field-Emission Scanning Electron Microscopy). The structure and morphology of these materials are closely related to the nature and amount of the precursor, and their microporosity increases proportionally to the molar percentage of ClRTEOS. In addition, the influence of the chlorine atom was investigated through comparison with their non-chlorinated analogues (RTEOS, R = M, E, or P) prepared in previous studies. The results showed that a smaller amount of precursor was needed to detect ordered domains (ladders and T₈ cages) in the local structure. The possibility of coupling self-organization with tailored porosity opens the way to novel applications for this type of organically modified silicates. Full article

In this paper, a new polyhedral oligomeric silsesquioxane containing a phenol group (POSS-Phenol) is prepared through the Michael addition reaction, which is added to the synthesis of phenolic resin as a functional monomer. Infrared spectroscopy (IR) is used to demonstrate the chemistry structure of the synthesized POSS modified phenolic resin. After introducing POSS into the resole, a comprehensive study is conducted to reveal the effects of POSS on the thermal degradation of phenolic resin. First, thermal degradation behaviors of neat phenolic resin and modified phenolic resin are carried out by thermogravimetric analysis (TGA). Then, the gas volatiles from thermal degradation are investigated by thermogravimetric mass spectrometry (TG-MS). Finally, the residues after thermal degradation are characterized by X-ray diffraction (XRD). The research indicates that POSS modified phenolic resin shows a better thermal stability than neat phenolic resin, especially at high temperatures under air atmosphere. On the one hand, the introduction of the POSS group can effectively improve the release temperature of oxygen containing volatiles. On the other hand, the POSS group forms silica at high temperatures under air, which can effectively inhibit the thermal oxidation of phenolic resin and make phenolic resin show a better high-temperature oxidation resistance. Full article

Silicones are often used for various types of coatings, but due to their poor mechanical properties, they often require modification to meet specific requirements. At the same time, various production processes throughout the world generate different types of waste, the disposal of which is harmful to the environment. One possible solution is to use production waste as a filler. In this paper, the authors investigated how the use of metallurgical production waste products as fillers changed the mechanical properties of silicone composites prepared by casting. Composite samples were characterized using tensile tests, resilience, pin-on-disc, Schopper–Schlobach abrasion, hardness, and density measurements. Based on the obtained results, the authors assessed the effect of each of the fillers used in different weight proportions. The results showed that the silicone composite filled with 5 wt% zinc dust showed the lowest decrease in tensile strength and Young’s modulus, with a simultaneous significant reduction in abrasion compared with the reference sample. This research shows that zinc waste can be successfully introduced into a silicone matrix in cases where it is important to reduce abrasive wear. Full article

This study reports a novel series of imidazolium ionic liquids (ILs) based on polyhedral oligomeric silsesquioxanes (POSS) towards effective detection of metal ions, especially Fe3+ ion. ¹H, ¹³C, ²⁹Si NMR, high resolution mass spectra (HRMS) and Fourier transform infrared spectra (FTIR) were applied to confirm the structures of the ILs based on POSS (ILs-POSS). The three ILs-POSS were synthesized via a green chemistry approach—a thiol-ene “click” reaction without metal ions as catalysts. Furthermore, the spherical vesicle structures of the ILs-POSS were observed and caused by self-assembly behaviors. Through comprehensive characterizations, these ILs-POSS have performed excellent thermal stabilities and low glass transition temperatures. In addition, we found it very meaningful that the limits of detection (LODs) of the three ILs-POSS for the detection of the Fe³⁺ ion were 7.91 × 10⁻⁸ M, 1.2 × 10⁻⁷ M, and 1.2 × 10⁻⁷ M, respectively. These data illustrate that these ILs-POSS have great potential for the detection of the Fe³⁺ ion. In conclusion, this study not only prepared novel ILs-POSS, but also provided new materials as fluorescent sensors in the detection of Fe³⁺. Full article

Poly(dimethylsiloxane) (PDMS) has been extensively used as an electroactive polymer material because it exhibits not only excellent moldability but also mechanical properties sufficient enough for electroactive performance despite low dielectric permittivity. Its low dielectric property is due to its molecular non-polarity. Here, we introduce a polar group into a PDMS elastomer by using vinyl acetate (VAc) as a crosslinker to improve the dielectric permittivity. We synthesized a high-molecular weight PDMS copolymer containing vinyl groups, namely poly(dimethylsiloxane-co-methylvinylsiloxane) (VPDMS), and prepared several of the VPDMS solutions in VAc. We obtained transparent PDMS films by UV curing of the solution layers. Electromechanical actuation-related physical properties of one of the UV-cured films were almost equivalent to or superior to those of platinum-catalyzed hydrosilylation-cured PDMS films. In addition, saponification of the UV-cured film significantly improved the electrical and mechanical properties (ɛ′ ~ 44.1 pF/m at 10 kHz, E ~ 350 kPa, ɛ ~ 320%). The chemical introduction of VAc into PDMS main chains followed by saponification would offer an efficacious method of enhancing the electroactive properties of PDMS elastomers. Full article

We report high refractive-index (RI) films composed of polyhedral oligomeric silsesquioxane (SSQ) matrices and various lanthanoid cations. The SSQ matrices were constructed from octaammonium SSQ by connecting with bipyridine dicarboxylic acid, which is expected to capture cations. By modulating the feed ratio between SSQ and dicarboxylic acid, the series of the SSQ matrices were obtained with variable cross-linking ratios among the SSQ units. Thin transparent films were able to be prepared through the drop-casting method with the aqueous mixtures containing SSQ matrices and various kinds of lanthanoid salts up to 40 wt %. From RI measurements, it was revealed that the increase of the amount of the metal ion can significantly lift up the RI values. In particular, critical losses of Abbe numbers, which theoretically have the trade-off relationship toward increases in RI values, were hardly detected. This effect could be obtained by cation assembly in local spots that are assisted by SSQ. Full article

The scientific reports on polyhedral oligomeric silsesquioxanes are mostly focused on the formation of completely condensed T₈ cubic type structures and recently so-called double-decker derivatives. Herein, we report on efficient synthetic routes leading to trifunctionalized, open-cage silsesquioxanes with alkenyl groups of varying chain lengths from -vinyl to -dec-9-enyl and two types of inert groups (iBu, Ph) at the silsesquioxane core. The presented methodology was focused on hydrolytic condensation reaction and it enabled obtaining titled compounds with high yields and purity. A parallel synthetic methodology that was based on the hydrosilylation reaction was also studied. Additionally, a thorough characterization of the obtained compounds was performed, also in terms of their thermal stability, melting and crystallization temperatures (TGA and DSC) in order to show the changes in the abovementioned parameters dependent on the type of reactive as well as inert groups at Si-O-Si core. The presence of unsaturated alkenyl groups has a profound impact on the application potential of these systems, i.e., as modifiers or comonomers for copolymerization reaction. Full article

Benzoxazine resin has been paid more attention in the fields of aviation, electronics, automobiles and new energy industries because of its excellent comprehensive performance. Further application is limited, however, by shortcomings such as high brittleness and high curing temperature. Furthermore, higher thermal stability is imperiously demanded in special areas. Incorporating both an acetylene group and silicon into the benzoxazine monomer is a promising possible solution to improve the curing processability, thermal properties and toughness of benzoxazine. In this paper, an acetylene-functional/silicon-containing benzoxazine monomer was prepared by two-step synthesis, and acetylene-functional benzoxazine was also prepared as a comparison. FTIR and ¹H NMR confirmed the molecular structure of acetylene-functional/silicon-containing benzoxazine. Differential scanning calorimetry (DSC) analysis showed that the initial and peak degradation temperatures of acetylene-functional/silicon-containing benzoxazine were decreased by 21 °C and 18 °C compared with acetylene-functional benzoxazine, respectively. The apparent activation energy of the curing reaction of acetylene-functional/silicon-containing benzoxazine was 83.1 kJ/mol, which was slightly lower than acetylene-functional benzoxazine (84.7 kJ/mol). TGA results showed that the acetylene-functional/silicon-containing benzoxazine had a higher thermal stability than acetylene-functional benzoxazine. The temperatures of 5% weight loss of acetylene-functional/silicon-containing benzoxazine were 380 °C in nitrogen and 485 °C in air, and the char yield at 1000 °C was 80% in nitrogen and 21% in air, respectively. The results of mechanical properties showed that the impact strength of acetylene-functional/silicon-containing benzoxazine was higher than acetylene-functional benzoxazine by 35.4%. The tensile and flexural strengths of acetylene-functional/silicon-containing benzoxazine were slightly higher than that of acetylene-functional benzoxazine. Full article

In this article we report an easy synthetic route towards hyperbranched polyglycerols (Amm-HBPGs) containing trimethylammonium groups and siloxane or hydroxyl end-groups. Siloxane derivatives of Amm-HBPGs were synthesized in an efficient five-step procedure including an anionic ring opening copolymerization of the phthalimide-epoxy monomer with glycidol, followed by reactions with allyl bromide, hydrosililation with hydrogenheptamethyltrisiloxane, hydrazinolysis of phthalimide groups and quaternization of resulting amine groups with methyl iodide. Hydroxyl derivatives were obtained by quaternization of previously reported aminated HBPG’s with methyl iodide. Polymeric products were characterized using various NMR techniques, FTIR, and elemental analysis. Both Amm-HBPGs were shown to be effective in catalysis of addition of CO₂ to oxirane. The hydrophilic catalysts showed higher efficiency but synthesis of ethylene carbonate was accompanied by formation of small amounts of ethylene glycol. The siloxane-containing catalyst was easily separable from reaction mixture showing high potential in the process of converting carbon dioxide into valuable chemical raw materials. Full article

Various amounts of methacryl polyhedral oligomeric silsesquioxane (POSS) were explored to be incorporated into novel nano SiO₂ dental resin composites using light curing method. The scanning electron microscopy (SEM), optical microscopy, fourier transform infrared spectroscopy (FTIR), nanoindentation, nanoscratch and three-point flexure tests were performed. The volumetric shrinkage and mechanical properties such as hardness, elastic modulus, resistance, flexural strength and fracture energy were analyzed. With the additions of POSS, the volume shrinkage decreased and the mechanical properties initially increased. The effects of POSS on these properties were studied to provide a reference for clinically selecting a composite resin with excellent properties. Full article

In this study, we synthesized two main chain–type block copolymers featuring hydrogen bond donor and acceptor segments through atom transfer radical polymerization (ATRP) using a bifunctionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticle as the initiator. Hydrosilylation of vinylbenzyl chloride at the two corners of a double-decker silsesquioxane (DDSQ) provided the bifunctionalized benzyl chloride initiator VBC-DDSQ-VBC, which we applied as a platform to prepare a main chain–type polystyrene homopolymer (PS-DDSQ-PS), the diblock copolymer poly(styrene–b–4-vinylpyridine) (P4VP-b-PS-DDSQ-PS-b-P4VP), and the diblock copolymer poly(styrene–b–tert-butoxystyrene) (PtBuOS-b-PS-DDSQ-PS-b-PtBuOS) through sequential ATRP. Selective hydrolysis of the tert-butoxyl units of PtBuOS-b-PS-DDSQ-PS-b-PtBuOS yielded the strongly hydrogen bonding diblock copolymer poly (styrene-b-vinylphenol) (PVPh-b-PS-DDSQ-PS-b-PVPh). We used Fourier transfer infrared spectroscopy, nuclear magnetic resonance spectroscopy, size exclusion chromatography, differential scanning calorimetry, mass-analyzed laser desorption ionization mass spectrometry, and transmission electron microscopy to investigate the chemical structures, thermal behavior, and self-assembled nanostructures formed by these main chain–type block copolymers based on DDSQ. Full article

This study investigated a new category of transparent encapsulant materials for light-emitting diodes (LEDs). It comprised a phenyl group that contained siloxane-modified epoxy (SEP-Ph) hybridized with a cyclic tetrafunctional siloxane-modified epoxy (SEP-D4) with methylhexahydrophthalic anhydride (MHHPA) as a curing agent. The SEP-Ph/SEP-D4 = 0.5/0.5 (sample 3) and SEP-D4 (sample 4) could provide notably high optical transmittance (over 90% in the visible region), high-temperature discoloration resistance, low stress, and more crucially, noteworthy sulfurization resistance. The lumen flux retention of the SEP encapsulated surface mounted device LEDs remained between approximately 97% and 99% after a sulfurization test for 240 h. The obtained comprehensive optical, mechanical, and sulfurization resistance proved the validity and uniqueness of the present design concept with complementary physical and chemical characteristics. Full article

Polyhedral oligomeric silsesquioxane (POSS) has been considered as one of the most promising nanofillers in academic and industrial research due to its unique multifunctional nanostructure, easy functionalization, hybrid nature, and high processability. The progress of POSS has been extensive, particularly applications based on single- or multiple-armed POSS. In polymer hybrids, in order to enhance the properties, bifunctional POSS has been incorporated into the backbone chain of the polymer. This review summarizes recent developments in the synthesis, modification, and application of bifunctional POSS-containing composite materials. This includes amino-POSS, hydroxyl-POSS, aromatic ring-POSS, ether-POSS, and vinyl groups-POSS and their applications, exemplified by polyurethanes (PUs) and polyimides (PIs). In addition, the review highlights the enhancement of thermal, mechanical, and optical properties of the composites. Full article

New organic-inorganic hybrid copolymers (EA-POSSs) based on butyl acrylate, glycidyl methacylate, hydroxybutyl acrylate, acryloiloxybenzophenone and acryloxypropyl-heptaisobutyl-POSS (A-POSS) were prepared via free-radical solution polymerization (FRP) and applied as a component of thermally curable structural self-adhesive tapes (SATs). The EA-POSS with 0.25, 0.5 or 1 mol % of A-POSS exhibited significantly higher dynamic viscosity (ca. +104%), Mw (+61%) and polydispersity (+109%; measured using gel permeation chromatography) as well as lower T_g value (−16 °C) in relation to the A-POSS-free copolymer (EA-0). Differential scanning calorimetry (DSC) measurements (one glass transition process) confirmed statistic chain structure of the EA-POSS materials. Replacement of EA-0 by the EA-POSS copolymers in a SATs recipe caused simultaneous improvement of their self-adhesive features, i.e., adhesion (+70%), tack (+21%) and cohesion (+1590%). Moreover, the POSS-based copolymers improved the shear strength of thermally cured Al/SAT/Al overlap joints; the best mechanical resistance (before and after accelerated ageing tests) was observed for the sample containing 0.5 mol % of A-POSS (an increment range of 50–294% in relation to the A-POSS-free joints). Thermogravimetric analysis (TGA) revealed markedly improved thermal stability of the A-POSS-based SATs as well. Full article

As one of the main consumables of interior decoration and furniture, decorative paper can be seen everywhere in the indoor space. However, because of its high content of formaldehyde, it has a certain threat to people’s health. Therefore, it is necessary to develop and study new formaldehyde-free decorative paper to meet the market demand. In this work, we have obtained formaldehyde-free decorative paper with high CO₂ adsorption capacity. Here, cellulose nanocrystals (CNC) were prepared by hydrolyzing microcrystalline cellulose with sulfuric acid. The N-(2-aminoethyl) (3-amino-propyl) methyldimethoxysilane (AEAPMDS) was grafted onto the CNCs by liquid phase hydrothermal treatment, and the aqueous solution was substituted by tert-butanol to obtain aminated CNCs (AEAPMDS-CNCs). The as-prepared AEAPMDS-CNCs were applied to formaldehyde-free decorative paper by the spin-coating method. The effects of various parameters on the properties of synthetic materials were systematically studied, and the optimum reaction conditions were revealed. Moreover, the surface bond strength and abrasion resistance of modified formaldehyde-free decorative paper were investigated. The experimental results showed that AEAPMDS grafted successfully without destroying the basic morphology of the CNCs. The formaldehyde-free decorative paper coated with AEAPMDS-CNCs had high CO₂ adsorption capacity and exhibited excellent performance of veneer to plywood. Therefore, laminating the prepared formaldehyde-free decorative paper onto indoor furniture can achieve the purpose of capturing indoor CO₂ and have a highly potential use for the indoor decoration. Full article

The excellent performance and wide applications of phenyl polysiloxanes are largely due to their phenyl units and monomer sequences. However, the relationship between molecular structure and material properties has not been explicitly elucidated. In this work, the sequence distribution and microstructure of random copolymers were quantitatively investigated by means of a molecular dynamics (MD) simulation combined with experimental verification. The results of ²⁹Si NMR showed that the large number of phenyl units not only shortened the length of the dimethyl units, but also significantly increased the proportion of consecutive phenyl units. The simulation results indicated the attraction between adjacent phenyl groups that were effectively strengthened intra- and inter- molecular interactions, which determined the equilibrium population of conformations and the dynamics of conformational transitions. Furthermore, the evolution of bond angle distribution, torsion distribution, and mean-squared displacements (MSD) shed light on the conformational characteristics that induce the unique thermodynamics properties and photophysical behavior of high-phenyl polysiloxanes. Differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), spectrofluorimetry, and laser scanning confocal microscopy (LSCM) were performed to verify the conclusions drawn from the simulation. Overall, the complementary use of MD simulations and experiments provided a deep molecular insight into structure–property relationships, which will provide theoretical guidance for the rational design and preparation of high-performance siloxanes. Full article

Novel nanocomposites for dielectric applications-based polypropylene/poly(ethylene-co-octene) (PP/POE) blends filled with nano silica are developed in the framework of the European ‘GRIDABLE’ project. A tailor-made low-pressure-plasma reactor was applied in this study for an organic surface modification of silica. Acetylene gas was used as the monomer for plasma polymerization in order to deposit a hydrocarbon layer onto the silica surface. The aim of this modification is to increase the compatibility between silica and the PP/POE blends matrix in order to improve the dispersion of the filler in the polymer matrix and to suppress the space charge accumulation by altering the charge trapping properties of these silica/PP/POE blends composites. The conditions for the deposition of the acetylene plasma-polymer onto the silica surface were optimized by analyzing the modification in terms of weight loss by thermogravimetry (TGA). X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray fluorescence spectroscopy (EDX) measurements confirmed the presence of hydrocarbon compounds on the silica surface after plasma modification. The acetylene plasma modified silica with the highest deposition level was selected to be incorporated into the PP/POE blends matrix. X-ray diffraction (XRD) showed that there is no new crystal phase formation in the PP/POE blends nanocomposites after addition of the acetylene plasma modified silica. Differential scanning calorimetry results (DSC) show two melting peaks and two crystallization peaks of the PP/POE blends nanocomposites corresponding to the PP and POE domains. The improved dispersion of the silica after acetylene plasma modification in the PP/POE blends matrix was shown by means of SEM–EDX mapping. Thermally stimulated depolarization current (TSDC) measurements confirm that addition of the acetylene plasma modified silica affects the charge trapping density and decreases the amount of injected charges into PP/POE blends nanocomposites. This work shows that acetylene plasma modification of the silica surface is a promising route to tune charge trapping properties of PP/POE blend-based nanocomposites. Full article

Novel fluorinated polyhedral oligomeric silsesquioxane (POSS) acrylic copolymers were synthesized by the radical solution polymerization. The superhydrophobic coating was prepared using a one-step breath figure method. Chemical constitution, morphology, hydrophobicity, and anticorrosion ability of as-prepared coatings were investigated by the corresponding equipment. The addition of proper fluorinated POSS can synchronously promote the formation of the micro-nano convex structure and the enrichment of fluorinated groups on the surface. Compared to commercial acrylic coating, the fluorinated POSS coating presented enhanced anticorrosion performance. The impedance was the highest and the corrosion current density was the lowest for superhydrophobic coating with 25 wt % fluorinated POSS. Full article

Composites using agricultural and forestry residues as raw materials with potentially high-performance, multifunctional and biodegradable ecological advantages, are viewed as very promising for new-generation lightweight and low-cost bio-based sustainable building materials. At present, the research on wood-plastic composite materials is relatively mature. However, it is still a challenge to effectively use other biomass and improve the interface of the high-polymer compound system. Herein, we proposed a simple and effective method to enhance the interfacial adhesion properties of rice husk fibre and High Density Polyethylene (HDPE) composites by the silane coupling agent KH-550 and compatibilizer Maleic anhydride grafted polyethylene (MAPE) with complementary modification. It was found that the coupling agent KH-550 cross-linked with the hydroxyl group on the husk fibre surface and solidified with the high polymer by –NH–, –C=O– functional group generation. Compatibilizer MAPE strengthened the two phases by covalently bonding with an ester linkage and lowered the roughness of the cross-section of the composites. Meanwhile the modification enhanced the dispersibility, and mechanical properties of the husk-high polymer compound system, the bending and flexural strength were improved by 11.5% and 28.9% with KH-550, and MAPE added, respectively. The flexural strength of the composites increased by 40.7% after complementary modification. Furthermore, the complementary modification treatment reduced the hydrophilic hydroxyl groups and increased the molecular chain to improve the water-resistance, elastic modulus and toughness of the composite. This study prepared a bio-composite, which is expected to expand the use of agricultural and forestry residues as an extension of wood-plastic composites. Full article

This article demonstrates a dispersed-monolayer graphene-doped polymer/silica hybrid Mach–Zehnder interferometer (MZI) thermal optical switch with low-power consumption and fast response. The polymer/silica hybrid MZI structure reduces the power consumption of the device as a result of the large thermal optical coefficient of the polymer material. To further decrease the response time of the thermal optical switch device, a polymethyl methacrylate, doped with monolayer graphene as a cladding material, has been synthesized. Our study theoretically analyzed the thermal conductivity of composites using the Lewis–Nielsen model. The predicted thermal conductivity of the composites increased by 133.16% at a graphene volume fraction of 0.263 vol %, due to the large thermal conductivity of graphene. Measurements taken of the fabricated thermal optical switch exhibited a power consumption of 7.68 mW, a rise time of 40 μs, and a fall time of 80 μs at a wavelength of 1550 nm. Full article

Crosslinked poly(dimethylsiloxane) (PDMS) has been widely used as a dielectric elastomer for electrically driven actuators because it exhibits high elasticity, low initial modulus, and excellent moldability in spite of low dielectric constant. However, further improvement in the characteristics of the PDMS elastomer is not easy due to its chemical non-reactivity. Here, we report a simple method for functionalizing the elastomer by varying content of hydridosilyl groups in PDMS acted as a crosslinker. We synthesized poly(dimethylsiloxane-co-methylvinylsiloxane) (VPDMS) and poly(dimethylsiloxane-co-methylsiloxane) (HPDMS). Tri(ethylene glycol) divinyl ether (TEGDE) as a polar molecule was added to the mixture of VPDMS and HPDMS. TEGDE was reacted to the hydridosilyl group in HPDMS during crosslinking between VPDMS and HPDMS in the presence of platinum as a catalyst. Permittivity of the crosslinked film increased from ca. 25 to 36 pF/m at 10 kHz without a decline in other physical properties such as transparency and elasticity (T > 85%, E ~150 kPa, ɛ ~270%). It depends on the hydridosilyl group content of HPDMS. The chemical introduction of a new molecule into the hydridosilyl group in HPDMS during crosslinking would provide a facile, effective method of modifying the PDMS elastomers. Full article

Soy protein isolate (SPI) has attracted considerable attention in the field of packaging technology due to its easy processability, biodegradability, and good film-forming characteristics. However, SPI-based films often suffer from inferior mechanical properties and high moisture sensitivity, thus restricting their practical application. In the present study, herein, a biobased nanocomposite film was developed by cross-linking SPI matrix from the synergistic reinforcement of cellulose nanofibers (CNF) and nano-silica (NS) particles. First, we functionalized the CNF with NS using a silane agent (KH560) as an efficient platform to enhance the interfacial interaction between SPI and CNF/NS, resulting from the epoxy-dominated cross-linking reaction. The chemical structure, thermal stability, and morphology of the resultant nanocomposite films were comprehensively investigated via Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). These results supported successful surface modification and indicated that the surface-tailored CNF/NS nanohybrid possesses excellent adhesion with SPI matrix through covalent and hydrogen-bonding interactions. The integration of CNF/NS into SPI resulted in nanocomposite films with an improved tensile strength (6.65 MPa), representing a 90.54% increase compared with the pristine SPI film. Moreover, the resulting composites had a significantly decreased water vapor permeation and a higher water contact angle (91.75°) than that of the unmodified film. The proposed strategy of synergistic reinforcements in the biobased composites may be a promising and green approach to address the critical limitations of plant protein-based materials in practical applications. Full article

A kind of core-shell hybrid nanoparticle comprised of a hollow mesoporous silica nanoparticles (HMS) core and a copolymer shell bearing N-(3,4-dihydroxyphenethyl) methacrylamide (DMA) and N-isopropylacrylamide (NIPAM) as responsive moieties was prepared. Moreover, the factors that could impact the surface morphology and hierarchical porous structure were discussed. In the presence of Fe³⁺, catechol-Fe³⁺ complexes were formed to achieve pH-responsive polymer shell, combining with thermal-sensitiveness of poly(N-isopropylacrylamide). Doxorubicin (DOX) was applied as a model drug and the behaviors of its loading/release behaviors were investigated to prove the idea. The results exhibited a significant drug loading capacity of 8.6% and embed efficiency of 94.6% under 1 mg ml^–1 DOX/PBS solution. In fact, the loading capacity of drug can be easily improved to as high as 28.0% by increasing the DOX concentration. The vitro cytotoxicity assay also indicated that the as-prepared nanoparticles have no significant cytotoxicity on RAW 264.7 cells. The in vitro experiment showed that the cumulative release of DOX was obviously dependent on the temperature and pH values. This pH/temperature-sensitive hollow mesoporous silica nanosphere is expected to have potential applications in controlled drug release. Full article

Ester-functionalized styrene-butadiene rubber (dibutyl itaconate-styrene-butadiene rubber) (D-ESBR) was synthesized by low-temperature emulsion polymerization using dibutyl itaconate (DBI) as a modified monomer containing ester groups. Nonpetroleum-based silica with hydroxy groups was used as a filler to enhance the D-ESBR, which can provide excellent mechanical properties, low rolling resistance, and high wet skid resistance. During the preparation of the silica/D-ESBR nanocomposites, a hydrogen-bonding interface was formed between the hydroxy groups on the surface of silica and the ester groups in the D-ESBR macromolecules. As the content of ester groups in the D-ESBR increases, the dispersion of silica in the nanocomposites is gradually improved, which was verified by rubber process analyzer (RPA) and scanning electron microscopy (SEM). Overall mechanical properties of the silica/D-ESBR modified with 5 wt % DBI were improved and became superior to that of the non-modified nanocomposite. Compared with the non-modified silica/D-ESBR, the DBI modified silica/D-ESBR exhibited a lower tan δ value at 60 °C and comparable tan δ value at 0 °C, indicating that the DBI modified silica/D-ESBR had lower rolling resistance without sacrificing wet skid resistance. Full article

The commonly used materials in fog seal are emulsified asphalt and modified emulsified asphalt. Nevertheless, there are some intractable problems including aging under ultraviolet, poor permeability, and moisture susceptibility. Therefore, silicone resin polymer was used as a kind of innovative fog seal material in this study. Physicochemical properties of solidified silicone resin were characterized. X-ray computed tomography and 3D reconstruction technology were used to evaluate permeability and distribution of silicone resin polymer in an asphalt mixture. Moisture sensitivity and high-temperature performance of the asphalt mixture maintained by silicone resin polymer were also detected. The results show that surface characteristic of silicone resin can effectively isolate moisture, thereby improving moisture resistance of the asphalt mixture. Silicone resin was found to be evenly distributed throughout the pores of a sample when the dosage was 400 or 600 mL/m². The pore filling rate increased by 16.3% when the dosage was changed from 200 to 400 mL/m², whereas it only increased by 3.7% when dosage increased from 400 to 600 mL/m². Moisture damage resistance of asphalt mixtures generally increased as the dosage of silicone was increased. However, as the dosage increased from 400 to 600 mL/m², the growth rate in residual Marshall stability (RMS) and tensile strength ratio (TSR) slowed significantly since the pore filling effect of silicone has reached the upper limit. Dosage of silicone resin has little effect on the results of the rutting test while it has significant influence on Hamburg wheel tracking test (HWT). Furthermore, it was found that 400 mL/m² is the optimum silicone dosage for open-graded friction course (OGFC)-13 mixture in consideration of permeability, distribution, performance of mixture, and economic cost. Full article

New hybrid sol–gel coatings based on tetraethoxysilane (TEOS) and phytic acid (PA) were designed and applied to cotton; the flame-retardant properties of the treated fabrics were thoroughly investigated by means of flame-spread and forced-combustion tests. The first goal was to identify the TEOS:PA weight ratio that allowed the achievement of the best flame-retardant properties, with the lowest final dry add-on on the fabrics. Therefore, different TEOS:PA sols were prepared and applied to cotton, and the resulting coated fabrics were thoroughly investigated. In particular, solid-state NMR spectroscopy was exploited for assessing the condensation degree during the sol–gel process, even for evaluating the occurrence of possible reactions between phytic acid and the cellulosic substrate or the alkoxy precursor. It was found that a total dry add-on of 16 wt % together with 70:30 TEOS:PA weight ratio provided cotton with self-extinction, as clearly indicated by flame-spread tests. This formulation was further investigated in forced-combustion tests: a significant reduction of heat release rate (HRR), of the peak of HRR, and of total heat release (THR) was found, together with a remarkable increase of the residues after the test. Unfortunately, the treated fabrics were not resistant to washing cycles, as they significantly lost their flame-retardant properties, consequently to the partial removal of the deposited hybrid coatings. Full article

In the present research, to enhance interfacial wettability and adhesion between carbon fibers (CFs) and matrix resin, hydrophilic silica nanoparticles (SiO₂) were utilized to graft the surface of CFs. Polydopamine (PDA) as a “bio-glue” was architecturally built between SiO₂ and CFs to obtain a strong adhesion strength and homogenous SiO₂ distribution onto the surface of CFs. The facile modification strategy was designed by self-polymerization of dopamine followed by the hydrolysis of tetraethoxysilane (TEOS) onto carbon fibers. Surface microstructures and interfacial properties of CFs, before and after modification, were systematically investigated. The tight and homogeneous coverage of SiO₂ layers onto the CF surface, with the assistance of a PDA layer by self-polymerization of dopamine, significantly enhanced fiber surface roughness and wettability, resulting in an obvious improvement of mechanical interlocking and interfacial interactions between CFs and matrix resin. The interlaminar shear strength (ILSS) and the interfacial shear strength (IFSS) of CF/PDA/SiO₂ reinforced composites exhibited 57.28% and 41.84% enhancements compared with those of untreated composites. In addition, impact strength and the hydrothermal aging resistance of the resulting composites showed great improvements after modification. The possible reinforcing mechanisms during the modification process have been discussed. This novel strategy of developed SiO₂-modified CFs has interesting potential for interfacial improvements for advanced polymer composites. Full article

A simple and effective way to prepare multi-walled carbon nanotubes (MWNT)//silica hybrid microcapsules (colloidosomes) is presented. These microcapsules have been generated by emulsion templating in a biphasic oil-in-water (o/w) system. Two trialkoxysilanes of complementary polarity, (3-aminopropyl)triethoxysilane (APTES) and dodecyltriethoxysilane (DTES), were used to chemically immobilize the silica nanoparticles at the o/w interface and stabilize the as-generated Pickering emulsions. The effects of varying the o/w ratio and the concentration of the added solids on the type of emulsion formed, the oil droplet size, as well as the emulsion stability have been investigated. The emulsion phase fraction was dependent on the silica content while the droplet size increased with increasing oil volume percentage. A solid shell emerged around the oil droplets from copolymerization between silane monomers. The thickness of the resulting shells was several hundreds of nm. Although MWNTs and silica nanoparticles both were co-assembled at the o/w interface, silica has shown to be the sole stabilizer, with APTES being crucial for the formation of the shell structure. Drop-casting of the emulsion and air-drying led to hierarchical open porous MWNT-silica nanocomposites. These new structures are promising as electrically conductive thin films for variety of applications, such as electro-optics, encapsulation, or chemical sensing. Full article

MQ silicone resins represent a broad range of hydrolytic condensation products of monofunctional silane (M units) and tetrafunctional silane (Q units). In this work, a Bio-Phenol MQ silicone resin (BPMQ) was designed and synthesized by the hydrosilylation of hydrogen containing MQ silicone resin and eugenol in the presence of chloroplatinic acid. The structure, thermal property, and antibacterial property against Escherichia coli of the modified MQ silicone resin were investigated. The results showed that BPMQ has been prepared successfully, and the thermal stability of this modified polymer improved significantly because of the introduction of phenyl in eugenol. The temperature at the maximum degradation rate increased from 250 °C to 422.5 °C, and the residual yields mass left at 600 °C were increased from 2.0% to 28.3%. In addition, its antibacterial property against Escherichia coli was also enhanced markedly without adding any other antimicrobial agents. This improved performance is ascribed to special functional groups in the structure of eugenol. The BPMQ polymer is expected to be applied to pressure-sensitive adhesives and silicone rubber products for the biomedical field due to its reinforcing effect and antioxidant quality. Full article

Raspberry-like hollow-spheres-on-sphere (HSOS) particles with reactive surfaces, uniform sizes and monodisperse properties were rational designed and fabricated to immobilize gold nanoparticles for the catalytic reduction of 4-nitrophenol. HSOS polysilsesquioxane (PSQ) particles were constructed by an organic alkali catalyzed sol-gel process from trialkoxysilane precursors with stabilized polystyrene (PS) nanoparticles as both a sacrifice template and a Pickering emulsifier. The PSQ particles were fabricated in an ice bath with methyltrimethoxysilane and mercaptopropyltrimethoxysiane as a co-precursor, tetramethylammonium hydroxide (TMAH) as a catalyst, polyvinylpyrrolidone (PVP) and sodium lignosulfonat as co-stabilizers and PS latex as a hard template. The formation mechanism of the hierarchical particles was investigated in detail by the time study through imaging the particles at regular time intervals during the reaction process. Various effect factors on the morphology were studied systematically which showed that the precursor composition, the content of PS, TMAH and PVP are the most important factors. The hierarchical structure combined with the mercaptopropyl groups on both the surface and the skeleton to make it possible to adsorb guest molecules. Au nanoparticles were immobilized on the particles for the catalytic reduction of 4-nitrophenol to 4-aminophenol. The unique PSQ colloids with hollow-spheres-on-sphere extended the family of the hierarchical structures and has shown the potential applications in separations, drug delivery and heterogeneous catalysts. Full article

Surface imprinting is an effective and simple method to fabricate and retain imprinted templates and recognizable nanocavities after template extraction. The imprinted effects can be controlled depending on the surface morphological changes. In general, a planar film has a limited area compared to a structured film with relatively higher surface-to-volume (S/V) ratio (A/A₀), leading to the conventional sensing response upon the functionality of monomers in a fixed chemical composition. To increase the limited sensing properties and develop simple fabrication of porous arrays on a large area, we herein demonstrate the 2,4-dichlorophenoxyacetic acid (2,4-D, herbicide)-imprinted porous thin film lithographically patterned using photopolymerization and silica colloidal array as a master mold, derived by a unidirectional rubbing method. The resonant frequency changes with respect to the adsorption of 2,4-D molecules on a template-extracted porous poly(MAA-co-EGDMA) (MIP) film in a 10⁻¹ mM aqueous solution of 2,4-D for 1 h, and when compared to the planar MIP film, the higher sensing response (Δf = −283 ± 7 Hz ≈ 1543 ± 38 ng/cm²) appears on the porous MIP film due to the specific recognition toward the more accessible templated cavities of the structured porous array, indicating an imprinting effect (I_f) value of 3.5. In addition, a higher selectivity for 2,4-D was also displayed on the porous MIP film compared to other herbicides. From these results, it was revealed that these improved sensing properties can be determined from the effects of various parameters (template functionality, film structuring, hydroxyl groups of silica colloids, etc.). Full article

The development of porous polymeric membranes is an important area of application in separation technology. This article summarizes the development of porous polymers from the perspectives of materials and methods for membrane production. Polymers such as polyethylene, polydimethylsiloxane, polypropylene, polyimide, and polytetrafluoroethylene are reviewed due to their outstanding thermal stability, chemical resistance, mechanical strength, and low cost. Six different methods for membrane fabrication are critically reviewed, including thermally induced phase separation, melt-spinning and cold-stretching, phase separation micromolding, imprinting/soft molding, manual punching, and three-dimensional printing. Each method is described in details related to the strategy used to produce the porous polymeric membranes with a specific morphology and separation performances. The key factors associated with each method are presented, including solvent/non-solvent system type and composition, polymer solution composition and concentration, processing parameters, and ambient conditions. Current challenges are also described, leading to future development and innovation to improve these membranes in terms of materials, fabrication equipment, and possible modifications. Full article

As a new kind of functionalized polysiloxane with chemical reactivity, bio-phenol polysiloxane was synthesized through facile heterogeneous catalytic route. Bio-phenol polysiloxane/polycarbonate (Si/PC) block copolymer was synthesized via a three-step approach, and the effect of the amount of bio-phenol polysiloxane on the properties of Si/PC copolymer was then studied. The structure and morphology of Si/PC copolymer were characterized, showing that, when the amount of bio-phenol polysiloxane reached 20%, the pyrolysis temperature of Si/PC copolymer at 5% weight loss was 450.8 °C which was 76.1 °C higher than pure PC. The oxygen permeability of 20%Si/PC copolymer membrane was 502.65 cm³/m²·24h·0.1MPa, which was increased by 128.4% compared with pure PC membrane. The mechanical property and hydrophobicity of Si/PC copolymer had been improved. Full article

Well-defined polymer brushes attached to nanoparticles offer an elegant opportunity for surface modification because of their excellent mechanical stability, functional versatility, high graft density as well as controllability of surface properties. This study aimed to prepare hybrid materials with good dispersion in different solvents, and to endow this material with certain fluorescence characteristics. Well-defined diblock copolymers poly (styrene)-b-poly (hydroxyethyl methyl acrylate)–co-poly (hydroxyethyl methyl acrylate- rhodamine B) grafted silica nanoparticles (SNPs-g-PS-b-PHEMA-co-PHEMA-RhB) hybrid materials were synthesized via surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The SNPs surfaces were modified by 3-aminopropyltriethoxysilane (KH-550) firstly, then the initiators 2-Bromoisobutyryl bromide (BIBB) was attached to SNPs surfaces through the esterification of acyl bromide groups and amidogen groups. The synthetic initiators (SNPs-Br) were further used for the SI-ARGET ATRP of styrene (St), hydroxyethyl methyl acrylate (HEMA) and hydroxyethyl methyl acrylate-rhodamine B (HEMA-RhB). The results indicated that the SI-ARGET ATRP initiator had been immobilized onto SNPs surfaces, the Br atom have located at the end of the main polymer chains, and the polymerization process possessed the characteristic of controlled/“living” polymerization. The SNPs-g-PS-b-PHEMA-co-PHEMA-RhB hybrid materials show good fluorescence performance and good dispersion in water and EtOH but aggregated in THF. This study demonstrates that the SI-ARGET ATRP provided a unique way to tune the polymer brushes structure on silica nanoparticles surface and further broaden the application of SI-ARGET ATRP. Full article

A novel flame retardant (HSPCTP) was successfully designed and incorporated into a polycarbonate (PC) matrix. Combining the advantages of cyclotriphosphazene and silicone oil, PC/HSPCTP composites passed UL-94 V-0 rating testing with only 3 wt% HSPCTP, and their LOI value increased from 25.0% to 28.4%. The findings showed that HSPCTP exhibits both gas-phase and solid-phase flame-retardant effects. Furthermore, the incorporation of HSPCTP into PC could suppress the release of smoke. Finally, the flame-retardant mechanism is discussed in depth. Full article

Methoxyl-capped MQ silicone resin (MMQ) was first synthesized by the hydrosilylation of vinyl-containing MQ silicone resin and trimethoxysilane and then used in condensed room-temperature vulcanized (RTV) silicone rubber as a self-reinforced cross-linker. Results show that modified silicone rubber exhibits good light transmission. Compared with unmodified silicone rubber, the hardness, tensile strength and elongation of MMQ at the break are increased by 26.4 A, 2.68 MPa and 65.1%, respectively. In addition, the characteristic temperature of 10% mass loss is delayed from 353.5 °C to 477.1 °C, the temperature at maximum degradation rate is also delayed from 408.9 °C to 528.4 °C and the residual mass left at 800 °C is increased from 1.2% to 27.7%. These improved properties are assigned to the synergistic effect of the rigid structure of MMQ, the formation of a dense cross-linking structure in polymers and the uniform distribution of MMQ cross-linking agent in RTV silicone rubber. Full article

Detonation nanodiamonds, also known as ultradispersed diamonds, possess versatile chemically active surfaces, which can be adjusted to improve their interaction with elastomers. Such improvements can result in decreased dielectric and viscous losses of the composites without compromising other in-rubber properties, thus making the composites suitable for new demanding applications, such as energy harvesting. However, in most cases, surface modification of nanodiamonds requires the use of strong chemicals and high temperatures. The present study offers a less time-consuming functionalization method at 40 °C via reaction between the epoxy-rings of the modifier and carboxylic groups at the nanodiamond surface. This allows decorating the nanodiamond surface with chemical groups that are able to participate in the crosslinking reaction, thus creating strong interaction between filler and elastomer. Addition of 0.1 phr (parts per hundred rubber) of modified nanodiamonds into the silicone matrix results in about fivefold decreased electric losses at 1 Hz due to a reduced conductivity. Moreover, the mechanical hysteresis loss is reduced more than 50% and dynamic loss tangent at ambient temperature is lowered. Therefore, such materials are recommended for the dielectric energy harvesting application, and they are expected to increase its efficiency. Full article

Optically transparent polyimides with excellent thermal stability and shape memory effect have potential applications in optoelectronic devices and aerospace industries. A series of optically transparent shape memory polyimide hybrid films are synthesized from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2′-bis-(trifluoromethyl)biphenyl-4,4′-diamine (TFMB) with various polyhedral oligomeric silsesquioxane (POSS) contents and then subjected to thermal imidization. The hybrid films show good optical transparency (>80% at 400 nm and >95% at 500 nm) with cutoff wavelengths ranging from 318 to 336 nm. Following the incorporation of the inorganic POSS structure, the hybrid films exhibit excellent thermal stability with glass transition temperature (T_g) ranging from 351 to 372 °C. The hybrid films possess the highest T_g compared with the previously-reported shape memory polymers. These findings show that POSS is successfully utilized to develop transparent polyimides with excellent thermal stability and shape memory effect. Full article

Polydimethylsiloxane (PDMS) is widely utilized in material science, chemical engineering, and environmental science due to its excellent properties. By utilizing fillers, so-called composite materials can be obtained with enhanced mechanical, wettability, or thermal conductivity performance. Here, we present a simple, cost-effective approach to vary either the mechanical properties (Young’s modulus) or surface wettability of bulk PDMS and PDMS sponges simply by adding nanodiamond filler with different surface terminations, either oxidized (oND) or hydrogenated (reduced, rND) nanodiamond. Minuscule amounts of oxidized nanodiamond particles as filler showed to benefit the compressive Young’s modulus of composite sponges with up to a 52% increase in its value, while the wettability of composite sponges was unaffected. In contrast, adding reduced nanodiamond particles to PDMS yielded inclined water contact angles on the PDMS/nanodiamond composite sponges. Finally, we show that the PDMS/rND composites are readily utilized as an absorbent for oil/water separation problems. This signifies that the surface termination of the ND particle has a crucial effect on the performance of the composite. Full article

In this study, silicone-based hydrogel contact lenses were prepared by the polymerization of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane (TRIS), N,N-dimethylacrylamide (DMA), 1-vinyl-2-pyrrolidinone (NVP), and 2-hydroxyethylmethacrylate (HEMA). The properties of silicone hydrogel lenses were analyzed based on the methods such as equilibrium water content, oxygen permeability, optical transparency, contact angle, mechanical test, protein adsorption, and cell toxicity. The results showed that the TRIS content in all formulations increased the oxygen permeability and decreased the equilibrium water content, while both DMA and NVP contributed the hydrophilicity of the hydrogels. The maximum value of oxygen permeability was 74.9 barrers, corresponding to an equilibrium water content of 44.5% as well as a contact angle of 82°. Moreover, L929 fibroblasts grew on all these hydrogels, suggesting non-cytotoxicity. In general, the silicone hydrogels in this work exhibited good oxygen permeability, stiffness, and optical transparency as well as anti-protein adsorption. Hence, these silicone hydrogel polymers would be feasible for making contact lens. Full article

The reactive acrylate-terminated CdZnSeS/ZnS quantum dots (QDs) were designed and prepared by the effective synthetic route to bond with a siloxane matrix via hydrosilylation. The conventional QD with oleic acid ligands does not have any reactivity, so the QDs were functionalized to assign reactivity for the QDs by the ligand modification of two step reactions. The oleic acid of the QDs was exchanged for hydroxyl-terminated ligands as an intermediate product by one-pot reaction. The hydroxyl-terminated QDs and acrylate-containing isocyanates were combined by nucleophilic addition reaction with forming urethane bonds and terminal acrylate groups. No degradation in quantum yield was observed after ligand exchange, nor following the nucleophilic addition reaction. The modification reactions of ligands were quantitatively controlled and their molecular structures were precisely confirmed by FT-IR and ¹H-NMR. The QDs with acrylate ligands were then reacted with hydride-terminated polydimethylsiloxane (H-PDMS) to form a QD-siloxane matrix by thermal curing via hydro-silylation for the first time. The covalent bonding between the QDs and the siloxane matrix led to improvements in the stability against oxygen and moisture. Stability at 85 °C and 85% relative humidity (RH) were both improved by 22% for the QD-connected siloxane QD films compared with the corresponding values for conventional QD-embedded poly(methylmethacrylate) (PMMA) films. The photo-stability of the QD film after 26 h under a blue light-emitting diode (LED) was also improved by 45% in comparison with those of conventional QD-embedded PMMA films. Full article

Nanocomposite membranes are strongly desired to break a trade-off between permeability and selectivity. This work reports new thin film nanocomposite (TFN) forward osmosis (FO) membranes by embedding aluminosilicate nanotubes (ANTs) into a polyamide (PA) rejection layer. The surface morphology and structure of the TFN FO membranes were carefully characterized by FTIR, XPS, FESEM and AFM. The ANTs incorporated PA rejection layers exhibited many open and broad “leaf-like” folds with “ridge-and-valley” structures, high surface roughness and relatively low cross-linking degree. Compared with thin film composite (TFC) membrane without ANTs, the TFN membrane with only 0.2 w/v% ANTs loading presented significantly improved FO water permeability, selectivity and reduced structural parameters. This promising performance can be mainly contributed to the special ANTs embedded PA rejection layer, where water molecules preferentially transport through the nanochannels of ANTs. Molecular dynamic simulation further proved that water molecules have much larger flux through the nanotubes of ANTs than sodium and chloride ions, which are attributed to the intrinsic hydrophilicity of ANTs and low external force for water transport. This work shows that these TFN FO membranes with ANTs decorated PA layer are promising in desalination applications due to their simultaneously enhanced permeability and selectivity. Full article

A novel organic-inorganic hybrid containing allyl benzoxazine and polyhedral oligomeric silsesquioxane (POSS) was synthesized by the thiol-ene (click) reaction. The benzoxazine (BOZ)-containing POSS (SPOSS-BOZ) copolymerized with benzoxazine/epoxy resin was used to prepare composites of SPOSS-PBZ-E nanocomposites(NPs). The polymerization behavior was monitored by FTIR and non-isothermal differential scanning calorimetry (DSC), which showed that the composites had completely cured with multiple polymerization mechanisms according to the oxazine ring-opening and epoxy resin (EP) polymerization. The thermal properties of the organic–inorganic polybenzoxazine (PBZ) nanocomposites were analyzed by DSC and thermogravimetric analysis (TGA). Furthermore, the X-ray diffraction analysis and the scanning electron microscopy (SEM) micrographs of the SPOSS-PBZ-E nanocomposites indicated that SPOSS was chemically incorporated into the hybrid nanocomposites in the size range of 80–200 nm. The flame retardancy of the benzoxazine epoxy resin composites was investigated by limiting oxygen index (LOI), UL 94 vertical burn test, and cone calorimeter tests. When the amount of SPOSS reached 10% or more, the vertical burning rating of the curing system arrived at V-1, and when the SPOSS-BOZ content reached 20 wt %, the thermal stability and flame retardancy of the material were both improved. Moreover, in the cone calorimeter testing, the addition of SPOSS-BOZ hindered the decomposition of the composites and led to a reduction in the peak heat release rate (pHRR), the average heat release rate (aHRR), and the total heat release (THR) values by about 20%, 25%, and 25%, respectively. The morphologies of the chars were also studied by SEM and energy dispersive X-ray spectroscopy (EDX), and the flame-retardant mechanism of POSS was mainly a condensed-phase flame retardant. The ceramic layer was formed by the enrichment of silicon on the char surface. When there are enough POSS nanoparticles, it can effectively protect the combustion of internal polymers. Full article

In view of the accidents such as rock mass breakage, roof fall and coal slide in coal mines, polyurethane/mesoscopic fly ash (PU/MFA) reinforcement materials were produced from polymethylene polyphenylene isocyanate (PAPI), the polyether polyol, flame retardant, and MFA using stannous octanate as a catalyst. 3-Glycidoxypropyltrimethoxysilane (GPTMS) was grafted on MFA surface, aiming to improve the mechanical properties of PU/MFA composites. The analyses of infrared spectroscopy and compression resistance reveal that the GPTMS can be successfully attached to the surface of MFA, and the optimum modification dosage of GPTMS to MFA is 2.5 wt. % (weight percent). On this basis, the effect of GPTMS on the mechanical properties of PU/MFA reinforcement materials during the curing process was systematically investigated through a compression test, a fracture toughness test, a three-point bending test, a bond property test, and a dynamic mechanics analysis. The results show that the compression property, fracture toughness, maximum flexural strength, and bond strength of PU/MFA composites increase by 21.6%, 10.1%, 8.8%, and 19.3%, respectively, compared with the values before the modification. Furthermore, the analyses of scanning electron microscope and dynamic mechanics suggest that the coupling agent GPTMS can successfully improve the mechanical properties of PU/MFA composites because it eliminates the stress concentration and exerts a positive effect on the crosslink density and hardness of PU/MFA composites. Full article

Silicone rubber composites filled with nano-silica are currently widely used as high voltage insulating materials in power transmission and substation systems. We present a systematic study on the dielectric and mechanical performance of silicone rubber filled with surface modified and unmodified fumed nano-silica. The results indicate that the different interfaces between the silicone rubber and the two types of nano-silica introduce changes in their dielectric response when electrically stressed by a sinusoidal excitation in the frequency range of 10⁻⁴–1 Hz. The responses of pure silicone rubber and the composite filled with modified silica can be characterized by a paralleled combination of Maxwell-Wagner-Sillars interface polarization and DC conduction. In contrast, the silicone rubber composite with the unmodified nano-silica exhibits a quasi-DC (Q-DC) transport process. The mechanical properties of the composites (represented by their stress-strain characteristics) reveal an improvement in the mechanical strength with increasing filler content. Moreover, the strain level of the composite with a modified filler is improved. Full article

In this work, a series of heptaphenyl siloxane trisilanol/polyhedral oligomeric silsesquioxane (T₇-POSS) modified by polyols with different molecular weights were synthesized into liquid-like nanoparticle–organic hybrid materials using the grafted-from method. All grafted POSS nanoparticles changed from solid powders to liquid at room temperature. Polyurethane (PU) nanocomposites with POSS contents ranging from 1.75 to 9.72 wt % were prepared from these liquefied polyols-terminated POSS with polyepichlorohydrin (POSS–PECH). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the morphology of the POSS–PECH/PU nanocomposites. The results showed that the polyol-terminated POSS particles overcame the nanoagglomeration effect and evenly disperse in the polymeric matrix. The damping factor (tan δ) of resultant nanocomposites increased from 0.90 to 1.16, while the glass transition temperature decreased from 15.8 to 9.4 °C when POSS contents increased from 0 to 9.75 wt %. The gel content, tensile strength and Fourier transform infrared (FTIR) analyses demonstrated that the molecular thermal movement ability of the polyurethane (PU) matrix increased with increasing POSS hybrid content. Therefore, the improvement of the damping properties of the composites was mainly due to the friction-related losses occurring in the interface region between the nanoparticles and the matrix. Full article

Functional hybrid materials were successfully synthesized from low-cost waste products, such as oligochitosan (OCS) obtained from chitosan (one of the main components in crab shells) and nanosilica (nSiO₂) obtained from rice husk, in a 1:1 ratio (w/w), and their dispersion in the presence of carboxymethyl cellulose at pH 7 was stable for over one month without aggregation. The molecular weights, chemical structures, morphologies, and crystallinities of the obtained materials were characterized by GPC, FTIR, TEM, and XRD, respectively. The antifungal effects of OCS, nSiO₂, and the OCS/nSiO₂ hybrid materials were investigated via a disk-diffusion method. The results showed that the nanohybrid materials had better resistance to Phytophthora infestans fungus than the individual components, and a concentration of the OCS2/nSiO₂ hybrid material of 800 mg L⁻¹ was the lowest concentration where the material completely inhibited Phytophthora infestans growth, as measured via an agar dilution method. This study not only creates a novel environmentally friendly material with unique synergistic effects that can replace current toxic agrochemicals but also can be considered a new platform for further research in green agricultural applications. Full article

Polyhedral oligomeric silsesquioxane (POSS)-derived Si@C anode material is prepared by the copolymerization of octavinyl-polyhedral oligomeric silsesquioxane (octavinyl-POSS) and styrene. Octavinyl-polyhedral oligomeric silsesquioxane has an inorganic core (-Si₈O₁₂) and an organic vinyl shell. Carbonization of the core-shell structured organic-inorganic hybrid precursor results in the formation of carbon protected Si-based anode material applicable for lithium ion battery. The initial discharge capacity of the battery based on the as-obtained Si@C material Si reaches 1500 mAh g⁻¹. After 550 charge-discharge cycles, a high capacity of 1430 mAh g⁻¹ was maintained. A combined XRD, XPS and TEM analysis was performed to investigate the variation of the discharge performance during the cycling experiments. The results show that the decrease in discharge capacity in the first few cycles is related to the formation of solid electrolyte interphase (SEI). The subsequent rise in the capacity can be ascribed to the gradual morphology evolution of the anode material and the loss of capacity after long-term cycles is due to the structural pulverization of silicon within the electrode. Our results not only show the high potential of the novel electrode material but also provide insight into the dynamic features of the material during battery cycling, which is useful for the future design of high-performance electrode material. Full article

The low viscosity of pure liquid CO₂ hindered the development of CO₂ fracturing technology. A modified silicone polymer was prepared as a CO₂ thickener to investigate the effect of temperature, pressure, shear rate and thickener content (wt.%) on the apparent viscosity and rheology of thickened liquid CO₂. In addition, CO₂ fracturing capacity was evaluated with the numerical simulation of extended finite element. The results displayed that an apparent viscosity of up to 1.3 mPa·s at 303 K and 18 MPa was attained over liquid CO₂ using the thickener of 3 wt.% and Toluene of 9 wt.% as additives. Compared to the commercial linear polydimethylsiloxane, a better apparent viscosity was obtained from the mixture of this prepared thickener, Toluene and CO₂. The apparent viscosity decreases with increasing temperature and shear rate. By contrast, an improving apparent viscosity was revealed with an increase in the pressure from 8 to 14 MPa and thickener content from 1 to 3 wt.%. The rheological index decreased with increasing thickener content with pressure but the rise in temperature led to an increasing rheological index. The mesh structure theory of the thickener, CO₂ and Toluene molecules was in this paper gives a good explanation for the discrepancy between CO₂ viscosity with the thickener content, temperature, pressure, or shear rate. Compared to pure CO₂, the numerical simulation of CO₂ fracturing demonstrated an excellent fracturing capacity by using the thickened CO₂ fracturing fluid in shale reservoirs. This investigation could provide the basic reference for the development of CO₂ fracturing technology. Full article

In order to improve the performance of traditional sodium alginate (SA) hydrogels cross-linked by Ca²⁺ ions to meet greater application demand, a strategy was designed to structure novel SA-based gels (named OP-PN gels) to achieve both stimulus responsiveness and improved mechanical strength. In this strategy, the SA chains are co-cross-linked by CaCl₂ and cationic octa-ammonium polyhedral oligomeric silsesquioxane (Oa-POSS) particles as the first network, and an organically cross-linked poly(N-isopropyl acrylamide) (PNIPA) network is introduced into the gels as the second network. Several main results are obtained from the synthesis and characterization of the gels. For OP-PN gels, their properties depend on the content of both uniformly dispersed Oa-POSS and PNIPA network directly. The increased Oa-POSS and PNIPA network content significantly improves both the strength and resilience of gels. Relatively, the increased Oa-POSS is greatly beneficial to the modulus of gels, and the increased PNIPA network is more favorable to advancing the tensile deformation of gels. The gels with hydrophilic PNIPA network exhibit better swelling ability and remarkable temperature responsiveness, and their volume phase transition temperature can be adjusted by altering the content of Oa-POSS. The deswelling rate of gels increases gradually with the increase of POSS content due to the hydrophobic Si–O skeleton of POSS. Moreover, the enhanced drug loading and sustained release ability of the target drug bovine serum albumin displays great potential for this hybrid gel in the biomedical field. Full article

The effect of the anchoring group on the detailed polymerization kinetics was investigated using monomethacryloxy-heptaisobutyl POSS (1M-POSS). This compound was copolymerized with lauryl methacrylate (LM) as the base monomer, at various molar ratios. The process was initiated photochemically. The polymerization kinetics were followed by photo-DSC and photorheology while the polymers were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). For comparison, a methacrylate containing the branched siloxy-silane group (TSM) was also studied. It was found that the modifiers with a bulky substituent have a dual effect on the termination process: (i) At low concentrations, they increase the molecular mobility by increasing the free volume fraction, which leads to an acceleration of the termination and slows the polymerization; while (ii) at higher concentrations, they retard molecular motions due to the “anchor effect” that suppresses the termination, leading to acceleration of the polymerization. The anchor effect can also be considered from a different point of view: The possibility of anchoring a monomer with a long substituent (LM) around the POSS cage, which can further enhance propagation. These conclusions were derived based on kinetic results, determination of polymerization rate coefficients, and copolymer analysis. Full article

Over the past two decades, organic optoelectronic materials have been considered very promising. The attractiveness of this group of compounds, regardless of their undisputable application potential, lies in the possibility of their use in the construction of organic–inorganic hybrid materials. This class of frameworks also considers nanostructural polyhedral oligomeric silsesquioxanes (POSSs) with “organic coronae” and precisely defined organic architectures between dispersed rigid silica cores. A significant number of papers on the design and development of POSS-based organic optoelectronic as well as photoluminescent (PL) materials have been published recently. In view of the scientific literature abounding with numerous examples of their application (i.e., as OLEDs), the aim of this review is to present efficient synthetic pathways leading to the formation of nanocomposite materials based on silsesquioxane systems that contain organic chromophores of complex nature. A summary of stoichiometric and predominantly catalytic methods for these silsesquioxane-based systems to be applied in the construction of photoactive materials or their precursors is given. Full article

Fertilizer is very important for increasing food yield, but the extensive use of fertilizer will cause environmental pollution. To enhance the effectiveness of fertilizer, we developed the double organic silicone-modified recycled-oil-based polyurethane as a coating material to prepare degradable polymer coating urea for constant fertilizer release. The moisture, heat resistance, and sustained release properties of polyurethane coating materials were investigated by modification with hydroxyl-terminated polydimethyl silicone (HTPMS) and γ-Aminopropyl triethoxy silane (KH550). The content and distribution of the siloxane groups were effectively controlled by adjusting the content ratio of two kinds of organosilicon. Meanwhile, the organic–inorganic hybrid structure was further controlled to form three-dimensional networks with a uniform distribution and a small scale. The moisture and heat resistance of polyurethane were thus improved, resulting in reduced porosity and an excellent sustained release performance. Observably, the best sustained release property of modified polyurethane coated urea was obtained when the ratio of KH550 to HTPMS is 0.3:0.7. Full article

Multifunctional elastomer nanocomposites have been applied in several high-tech fields. The design of materials with tailored properties capable of tuning their performance is a topical challenge. Here, we demonstrate that it is possible to modulate the mechanical and transport properties of silicone rubber nanocomposites by controlling the structure, chemical composition and morphology of the graphene material. Intrinsic graphene properties, such as remaining oxygen groups, specific surface area, and aspect ratio, among others, have a profound effect on the final properties of the nanocomposite. Thus, the thermal conductivity benefits from larger filler size and high aromatic restoration. Whereas mechanical properties and electrical conductivity require a proper balance between filler/polymer matrix interaction and a partial aromatic restoration. Full article

A series of hybrid thermoplastic polyurethanes (PUs) were synthesized from bi-functional polyhedral oligomeric silsesquioxane (B-POSS) and polycaprolactone (PCL) using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent for the first time. The newly synthesized hybrid materials were fully characterized in terms of structure, morphology, thermal and mechanical performance, as well as their toughening effect toward polyesters. Thermal gravimeter analysis (TGA) and differential scanning calorimetry (DSC) showed enhanced thermal stability by 76 °C higher in decomposition temperature (T_d) of the POSS PUs, and 22 °C higher glass transition temperature (T_g) when compared with control PU without POSS. Static contact angle results showed a significant increment of 49.8° and 53.4° for the respective surface hydrophobicity and lipophilicity measurements. More importantly, both storage modulus (G’) and loss modulus (G’’) are improved in the hybrid POSS PUs and these parameters can be further adjusted by varying POSS content in the copolymer. As a biodegradable hybrid filler, the as-synthesized POSS PUs also demonstrated a remarkable effect in toughening commercial polyesters, indicating a simple yet useful strategy in developing high-performance polyester for advanced biomedical applications. Full article

Rigid polyurethane foams (RPUFs) were successfully modified with different weight ratios (0.5 wt%, 1.5 wt% and 5 wt%) of APIB-POSS and AEAPIB-POSS. The resulting foams were evaluated by their processing parameters, morphology (Scanning Electron Microscopy analysis, SEM), mechanical properties (compressive test, three-point bending test and impact strength), viscoelastic behavior (Dynamic Mechanical Analysis, DMA), thermal properties (Thermogravimetric Analysis, TGA, and thermal conductivity) and application properties (contact angle, water absorption and dimensional analysis). The results showed that the morphology of modified foams is significantly affected by the type of the filler and filler content, which resulted in inhomogeneous, irregular, large cell shapes and further affected the physical and mechanical properties of resulting materials. RPUFs modified with APIB-POSS represent better mechanical and thermal properties compared to the RPUFs modified with AEAPIB-POSS. The results showed that the best results were obtained for RPUFs modified with 0.5 wt% of APIB-POSS. For example, in comparison with unfilled foam, compositions modified with 0.5 wt% of APIB-POSS provide greater compression strength, better flexural strength and lower water absorption. Full article

Giant surfactants refer to a new kind of amphiphile by incorporating functional molecular nanoparticles with polymer tails. As a size-amplified counterpart of small-molecule surfactants, they serve to bridge the gap between small-molecule surfactants and amphiphilic block copolymers. This work reports the design and synthesis of single-tailed giant surfactants carrying a hydrophobic poly(ε-caprolactone) (PCL) as the tail and a hydrophilic cage-like polyhedral oligomeric silsesquioxane (POSS) nanoparticle as the head. The modular synthetic strategy features an efficient “growing-from” and “click-modification” approach. Starting from a monohydroxyl and heptavinyl substituted POSS (VPOSS-OH), a PCL chain with controlled molecular weight and narrow polydispersity was first grown by the ring-opening polymerization (ROP) of ε-CL under the catalysis of stannous octoate, leading to a PCL chain end-capped with heptavinyl substituted POSS (VPOSS-PCL). To endow the POSS head with adjustable polarity and functionality, three kinds of hydrophilic groups, including hydroxyl groups, carboxylic acids, and amine groups, were installed to the periphery of POSS molecule by a high-efficiency thiol-ene “click” reaction. The compounds were fully characterized by NMR, gel permeation chromatography (GPC), MALDI-TOF mass spectrometry, and TGA analysis. In addition, the preliminary self-assembly study of these giant surfactants was also investigated by TEM and dynamic laser light scattering (DLS), which indicated that they can form spherical nanoparticles with different diameters in aqueous solution. This work affords a straightforward and versatile way for synthesizing single-tailed giant surfactants with diverse head surface functionalities. Full article

Fouling Release Coatings are marine antifouling coatings based on silicone elastomers. Contrary to commonly used biocide-based antifouling coatings, they do not release biocides into the marine environment, however, they suffer from poor antifouling efficacy during idle periods. To improve their antifouling performances in static conditions, various amounts of hydrolyzable polymers were incorporated within a silicone matrix. These hydrolyzable polymers were chosen for the well-known hydrolytic degradation mechanism of their main chain, e.g. poly(ε-caprolactone) (PCL), or of their ester pending groups, e.g. poly(bis(trimethylsilyloxy)methylsilyl methacrylate) (PMATM2). The degradation kinetics of such hydrolyzable silicone coatings were assessed by mass loss measurements during immersion in deionized water. Coatings containing PMATM2 exhibited a maximum mass loss after 12 weeks, whereas PCL-based coatings showed no significant mass loss after 24 weeks. Dynamic contact angle measurements revealed the modifications of the coatings surface chemistry with an amphiphilic behavior after water exposure. The attachment of macrofoulers on these coatings were evaluated by field tests in the Mediterranean Sea, demonstrating the short or long-term antifouling effect of these hydrolyzable polymers embedded in the silicone matrix. The settlement of A. amphitrite barnacles on the different coatings indicated inhospitable behaviors towards larval barnacles for coatings with at least 15 wt % of additives. Full article

In this study, a novel copolymer, PbisDOPOMA-POSSMA-GMA (PDPG), containing methacryloisobutyl polyhedral oligomeric silsesquioxane (POSSMA), reactive glycidyl methacrylate (GMA), and bis-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide methacrylate (bisDOPOMA) and derivative functionalized graphene oxide (GO) were synthesized by a one-step grafting reaction to create a hybrid flame retardant (GO-MD-MP). GO-MD-MP was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Flame-retardant epoxy resin (EP) composites were prepared by adding various amounts of GO-MD-MP to the thermal-curing epoxy resin of diglycidyl ether of bisphenol A (DGEBA, trade name E-51). The thermal properties of the EP composites were remarkably enhanced by adding the GO-MD-MP, and the residue char of the epoxy resin also increased greatly. With the incorporation of 4 wt % GO-MD-MP, the limiting oxygen index (LOI) value was enhanced to 31.1% and the UL-94 V-0 rating was easily achieved. In addition, the mechanical strength of the epoxy resin was also improved. Full article

Three new triphenylamine-based oligomeric Schiff bases (polySB1, polySB2 and polySB3) containing tetraphenylsilane core (TPS-core) in the main chain were obtained from TPS-core-based diamines and bis(4-formylphenyl)phenylamine by a high-temperature polycondensation reaction. These new oligomers were structurally characterized by FT-IR, NMR and elemental analysis. All polySBs were highly soluble in common organic solvents, such as chloroform, tetrahydrofuran and chlorobenzene. Samples showed moderate molecular average molecular weight (Mw) and a high thermal stability above 410 °C. Likewise, polySBs showed absorption near 400 nm in the UV-vis range and photoluminescence. The HOMO levels and band-gap values were found in the ranges of −6.06 to −6.18 eV and 2.65–2.72 eV, respectively. The lowest band-gap value was observed for polySB2, which could be attributed to a more effective π-conjugation across the main chain. The results suggest that silicon-containing polySBs are promising wide-band-gap semiconductors materials for optoelectronic applications. Full article

Blends of cyanate ester and phthalonitrile–polyhedral oligomeric silsesquioxane copolymers were prepared, and their cure behavior and properties were compared via differential scanning calorimetry (DSC) analysis, thermogravimetric (TG) analysis, dynamic mechanical analysis, Fourier-transform far-infrared (FTIR) spectroscopy, and rheometric studies. The copolymer blends showed high chemical reactivity, low viscosity, and good thermal stability (TG temperatures were above 400 °C). The glass-transition temperature of the blends increased by at least 140 °C compared to cyanate ester resin. The blends are suitable for preparing carbon-fiber-reinforced composite materials via a winding process and a prepreg lay-up process with a molding technique. The FTIR data showed that the polymerization products contained triazine-ring structures that were responsible for the superior thermal properties. Full article

In the dynamic water environment, grouting requires a material with higher strength and anti-washout performance to prevent groundwater inrush. This study aims to develop a dynamic water slurry by mixing polypropylene fiber (PP fiber), silica fume (SF) and the polymer material of redispersible emulsion powder (REP) to the Portland cement. Towards this aim, a series of tests, including strength, gel time, bleeding rate, fluidity, and anti-washout, were conducted to evaluate the effects of SF, PP fiber, and REP on the slurry properties. The test results show that: (1) SF displays significant effects on strength, gel time, fluidity, and bleeding rate of cement slurry. Differently, PP fiber mainly affects the stress–strain behavior of the slurry and can improve the ductility significantly. (2) By mixing SF and fiber simultaneously, the slurry strength can increase by about 30%, and its strain can extend by more than 70%. Meanwhile, the composite slurry possesses great anti-washout properties at a low flow velocity (v ≤ 0.4 m/s), and the grouting retention rate (GRR) can reach up to 98.7%. However, the GRR decreases to a maximum value of 31.3% when v = 0.6 m/s. (3) By mixing the REP into the fiber-SF composite slurry, the GRR can further increase, reaching more than 60% even when v = 0.6 m/s. As a result, the developed fiber-SF cementitious composite slurry, which when mixed with REP, presents a favorable performance in the dynamic water environment. Full article

The self-healing ability can be imparted to the polymers by different mechanisms. In this study, self-healing polydimethylsiloxane-graft-polyurethane (PDMS-g-PUR)/Vanadium pentoxide (V₂O₅) nanofiber supramolecular polymer composites based on a reversible hydrogen bonding mechanism are prepared. V₂O₅ nanofibers are synthesized via colloidal route and characterized by XRD, SEM, EDX, and TEM techniques. In order to prepare PDMS-g-PUR, linear aliphatic PUR having one –COOH functional group (PUR-COOH) is synthesized and grafted onto aminopropyl functionalized PDMS by EDC/HCl coupling reaction. PUR-COOH and PDMS-g-PUR are characterized by ¹H NMR, FTIR. PDMS-g-PUR/V₂O₅ nanofiber composites are prepared and characterized by DSC/TGA, FTIR, and tensile tests. The self-healing ability of PDMS-graft-PUR and composites are determined by mechanical tests and optical microscope. Tensile strength data obtained from mechanical tests show that healing efficiencies of PDMS-g-PUR increase with healing time and reach 85.4 ± 1.2 % after waiting 120 min at 50 °C. The addition of V₂O₅ nanofibers enhances the mechanical properties and healing efficiency of the PDMS-g-PUR. An increase of healing efficiency and max tensile strength from 85.4 ± 1.2% to 95.3 ± 0.4% and 113.08 ± 5.24 kPa to 1443.40 ± 8.96 kPa is observed after the addition of 10 wt % V₂O₅ nanofiber into the polymer. Full article

The incorporation of polyhedral oligomeric silsesquioxanes (POSS) molecules as nanoparticles into polymers can provide improved physico-chemical properties. The enhancement depends on the extent of dispersion of the nanofiller, which is determined by the compatibility with the polymer that is by the POSS type, and the processing method. In this study, poly(ε-caprolactone)/POSS derivatives nanocomposites (PCL/POSS) were obtained via solution-casting and melt compounding. Two amino-derivatives containing different alkyl substituents, and ditelechelic POSS-containing hybrid PCL masterbatch were used as nanofillers. The effect of preparation method, POSS content and type on the morphology, thermal, mechanical, and surface properties of nanocomposites were studied. Morphological analysis evidenced the formation of POSS crystalline aggregates, self-assembled POSS molecules of submicrometer size dispersed in the polymer matrix. The best dispersion was achieved using the ditelechelic POSS-containing hybrid PCL masterbatch, and comparing the two amino-POSS derivatives, the one with longer alkyl chain of substituents exhibited better degree of dispersion independent of preparation method. DSC analysis showed the role of POSS derivatives as nucleating agents for PCL. The incorporation of POSS derivatives into the PCL matrix improved thermal stability. The preparation method, POSS type and content had influence on mechanical properties of nanocomposites. POSS nanoparticles enhanced the surface hydrophobicity of PCL. Full article

The preparation of hybrid nanocomposite materials derived from polyhedral oligomeric silsesquioxane (POSS) nanoparticles and polyimide (PI) has recently attracted much attention from both academia and industry, because such materials can display low water absorption, high thermal stability, good mechanical characteristics, low dielectric constant, flame retardance, chemical resistance, thermo-redox stability, surface hydrophobicity, and excellent electrical properties. Herein, we discussed the various methods that have been used to insert POSS nanoparticles into PI matrices, through covalent chemical bonding and physical blending, as well as the influence of the POSS units on the physical properties of the PIs. Full article

In this study, the konjac glucomannan (KGM)/carrageenan (KC)/nano-silica film was prepared and characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The preservation quality of white mushrooms (Agaricus bisporus) packed using the films was also determined. The nano-silica dosage was found to affect the properties of the nanocomposite KGM/KC films. The results indicated that the properties of the films were significantly improved with the addition of nano-silica. The water vapor permeability, water solubility, moisture absorption, and light transmittance of KGM/KC/nano-silica films were significantly affected by the nano-silica dosage. In this study, the optimal nano-silica dosage to incorporate into the film in order to achieve excellent performance was 0.3%. Strong intermolecular hydrogen bonds were also observed between KGM/KC and nano-silica in the KGM/KC/nano-silica film by FTIR. In addition, the KGM/KC/nano-silica film markedly reduced the browning index, delayed the weight loss and softening, and extended the shelf life of mushrooms during storage at 4 °C. The KGM/KC film modified using nano-silica can provide a potential method for improving the preservation quality of white mushrooms during storage. Full article

Three alternated D-π-A type 5,10-bis(triisopropylsilylethynyl)dithieno[2,3-d:2′,3′-d′]-benzo[1,2-b:4,5-b′]dithiophene (DTBDT-TIPS)-based semiconducting conjugated copolymers (CPs), PDTBDT-TIPS-DTBT-OD, PDTBDT-TIPS-DTFBT-OD, and PDTBDT-TIPS-DTNT-OD, bearing different A units, including benzothiadiazole (BT), 5,6-difluorinated-BT (FBT) and naphtho[1,2-c:5,6-c′]-bis[1,2,5]thiadiazole (NT), were designed and synthesized to investigate the impact of the variation in electron-deficient units on the properties of these photovoltaic polymers. It was exhibited that the down-shifted highest occupied molecular orbital energy level (E_HOMO), the enhanced aggregation in both the chlorobenzene solution and the solid film, as well as the better molecular planarity, were achieved using methods involving fluorination and the replacement of BT with NT on the polymer backbone. The absorption profile was little changed upon fluorination; however, it was greatly broadened during replacement of BT with NT. Consequently, the optimized photovoltaic device based on the PDTBDT-TIPS-DTNT-OD exhibited synchronous enhancements in the open-circuit voltage (V_OC) of 0.88 V, the short-circuit current density (J_SC) of 7.21 mA cm⁻², and the fill factor (FF) of 52.99%, resulting in a drastic elevation in the PCE by 129% to 3.37% compared to that of the PDTBDT-TIPS-DTBT-OD. This was triggered by PDTBDT-TIPS-DTNT-OD’s broadened absorption, deepened E_HOMO, improved coplanarity, and enhanced SCLC mobility (which increased 3.9 times), as well as a favorable morphology of the active layer. Unfortunately, the corresponding PCE deteriorated after incorporating fluorine into the BT, due to the oversized aggregation and large phase separation morphology in the blend films, severely impairing its J_SC. Our preliminary results demonstrated that the replacement of BT with NT in a D-π-A type polymer backbone was an effective strategy of tuning the molecular structure to achieve highly efficient polymer solar cells (PSCs). Full article

This article focuses on studying the rheological behavior of isotropic and anisotropic magnetorheological elastomers (MREs), made of carbonyl iron microparticles dispersed into a silicone–rubber matrix by considering 20 and 30 wt % of microparticles. Sample sets were prepared for each composition, with and without the application of an external magnetic field. Experimental measurements of the material rheology behavior were carried out by a shear oscillatory rheometer at constant temperature, to determine both the shear storage modulus (G′) and shear loss modulus (G′′) for all characterized samples. Then, experimental data collected from the isotropic and the anisotropic material samples were used to plot the Cole-Cole diagrams to quantify the interfacial adhesion between carbonyl iron microparticles and the silicone-rubber matrix. Furthermore, the Fractional Zener Model (FZM) with two spring-pots in series is used for quantitative analysis of collected experimental data. Full article

Poly(methylhydro)siloxane (PMHS) and n-hexane were used as modifiers and solvents, respectively, to prepare surface modification of microcrystalline cellulose (MCC). The response surface methodology was used to optimize the effects of reaction conditions on hydrophobicity of MCC. The optimal reaction conditions were determined as follows: the concentration of PMHS was 0.0275% (the mass ratio of PMHS to MCC), the reaction time was 20 min, and the drying temperature was 70 °C. Under the optimum reaction conditions, the water contact angle of modified MCC was 141.5°. It is feasible to optimize and select the reaction conditions of modified MCC by Design-Expert, and the predicted value of the mathematical model is in good agreement with the experimental value. Surface chemical characteristics were investigated using X-ray photoelectron spectroscopy (XPS). These analyses confirmed that the PMHS chains were attached to MCC. Due to the introduction of a large amount of methyl groups, the reaction between MCC and PMHS leads to an improvement in its hydrophobicity. Full article

The dual-functionalized polyhedral oligomeric silsesquioxane (POSS) derivatives, which have the seven fluorinated alkanes and the single acrylate ester on the silica cube, were designed as a filler for lowering the refractive index (RI) and improving thermomechanical properties in poly(methyl methacrylate) (PMMA). The desired dual-functionalized POSS fillers were prepared, and because of its high miscibility, homogeneous films were readily obtained, by the casting method, with the mixture solutions containing the modified POSS and the polymers. From optical measurements, it was found that the larger effects of lowering the RIs of the PMMA matrices were observed from the modified POSS than those of the octa-substituted POSS derivatives with the homogeneous substituents. It should be mentioned that the degradation temperatures and the storage moduli were able to be greatly elevated by loading the present POSS fillers. Finally, it was demonstrated that the methacrylate ester-tethered POSS should be the most effective filler for modulating PMMA (Δn = −0.020, ΔTd20 = +53 °C, ΔE’/E’ = +72%). Full article

With developments of the electronics industry, more components are being included in electronic devices, which has led to challenges in thermal management. Using reduced graphene oxide embedded with MQ silicone resin (RGO/MQ) nano-aggregates as the composite filler and silicone rubber (SR) as the matrix, a simple approach is designed to prepare RGO/MQ/SR composites. Reduced graphene oxide (RGO) was first used as a substrate for the growth of MQ silicone resin by hybridization, forming sandwich-like micro structured RGO/MQ nano-aggregates successfully. Then, RGO/MQ was integrated into α,ω-dihydroxylpolydimethylsiloxane based on the in situ solvent-free blending method, followed by condensation and vulcanization, fabricating the final RGO/MQ/SR composites. The effective strategy could enhance the adaptability between graphene and silicone matrix under external stimuli at room temperature by embedding nanoscale MQ into the interface of graphene/silicone as the buffer layer. Obvious improvements were found in both thermal conductivity and mechanical properties due to excellent dispersion and interfacial compatibility of RGO/MQ in the host materials. These attractive results suggest that this RGO/MQ/SR composite has potential as a thermal interface material for heat dissipation applications. Full article

The graphene nanosheets (GNS)/polydimethylsiloxane (PDMS) composite films with out-of-plane dielectric actuation behavior were prepared through a layer-by-layer spin coating process. The GNS-PDMS/PDMS composite films with 1~3 layers of GNS-PDMS films were spin coated on top of the PDMS film. The dielectric, mechanical, and electromechanical actuation properties of the composite films were investigated. The dielectric constant of the GNS-PDMS³/PDMS composite film at 1 kHz is 5.52, which is 1.7 times that of the GNS-PDMS¹/PDMS composite film. The actuated displacement of the GNS-PDMS/PDMS composite films is greatly enhanced by increasing the number of GNS-PDMS layers. This study provides a novel alternative approach for fabricating high-performance actuators with out-of-plane actuation behavior. Full article

Eugenol, used as bio-phenol, was designed to replace the hydrogen atom of hydrogenterminated siloxane by hydrosilylation reaction under the presence of alumina-supported platinum catalyst (Pt-Al₂O₃), silica-supported platinum catalyst (Pt-SiO₂) and carbon nanotube-supported platinum catalyst (Pt-CNT), respectively. The catalytic activities of these three platinum catalysts were measured by nuclear magnetic resonance hydrogen spectrometer (¹H NMR). The properties of bio-phenol siloxane were characterized by Fourier transform infrared spectrometer (FT–IR), UV-visible spectrophotometer (UV) and thermogravimeter (TGA), and its antibacterial property against Escherichia coli was also studied. The results showed that the catalytic activity of the catalyst Pt-CNT was preferable. When the catalyst concentration was 100 ppm, the reaction temperature was 80 °C and reaction time was 6 h, the reactant conversion rate reached 97%. After modification with bio-phenol, the thermal stability of the obtained bio-phenol siloxane was improved. For bio-phenol siloxane, when the ratio of weight loss reached 98%, the pyrolysis temperature was raised to 663 °C which was 60 °C higher than hydrogenterminated siloxane. Meanwhile, its autonomic antibacterial property against Escherichia coli was improved significantly. Full article

A novel group of silsesquioxane derivatives, which are siloxane-silsesquioxane resins (S4SQ), was for the first time examined as possible flame retardants in polypropylene (PP) materials. Thermal stability of the PP/S4SQ composites compared to the S4SQ resins and neat PP was estimated using thermogravimetric (TG) analysis under nitrogen and in air atmosphere. The effects of the non-functionalized and n-alkyl-functionalized siloxane-silsesquioxane resins on thermostability and flame retardancy of PP materials were also evaluated by thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR) and by cone calorimeter tests. The results revealed that the functionalized S4SQ resins may form a continuous ceramic layer on the material surface during its combustion, which improves both thermal stability and flame retardancy of the PP materials. This beneficial effect was observed especially when small amounts of the S4SQ fillers were applied. The performed analyses allowed us to propose a possible mechanism for the degradation of the siloxane-silsesquioxane resins, as well as to explain their possible role during the combustion of the PP/S4SQ composites. Full article

Both cellulose nanofiber (CNF) and carbon nanotube (CNT) are nanoscale fibers that have shown reinforcing effects in polymer composites. It’s worth noting that CNF and CNT could form a three-dimensional nano-network via mixing and vacuum filtration, which exhibit excellent mechanical strength and electrical conductivity. In this study, the developed CNF/CNT film was applied as a nano-network template and immersed into polydimethylsiloxane (PDMS) solutions. By controlling the immersed polydimethylsiloxane pre-polymer concentration, the PDMS/CNF/CNT nanocomposite with various PDMS contents were fabricated after a curing process. Morphological images showed that the CNF/CNT nano-network was well-preserved inside the PDMS, which resulted in significantly improved mechanical strength. While increasing the PDMS content (~71.3 wt %) gave rise to decreased tensile strength, the PDMS-30/CNF/CNT showed a fracture strain of 7.5%, which was around seven fold higher than the rigid CNF/CNT and still kept a desirable strength—Young’s modulus and conductivity of 18.3 MPa, 805 MPa, and 0.8 S/cm, respectively. Therefore, with the enhanced mechanical properties and the electrical conductivity, the prepared PDMS/CNF/CNT composite films may offer promising and broad prospects in the field of flexible devices. Full article

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing. Full article

In this paper, two different models of hybrid ionic liquids (ILs) based on polyhedral oligomeric silsesquioxanes (POSSs) have been prepared. Additionally, these ILs based on POSSs (ILs-POSSs) exhibited excellent thermal stabilities and low glass transition temperatures. ¹H, ¹³C, and ²⁹Si nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were used to confirm the structures of the IL-POSSs. Furthermore, the spherical vesicle structures of two IL-POSSs were observed and were caused by self-assembly behaviors. In addition, we found it very meaningful that these two ILs showed lower detection limits of 2.57 × 10⁻⁶ and 3.98 × 10⁻⁶ mol/L for detecting picric acid (PA). Moreover, the experimental data revealed that the products have high sensitivity for detecting a series of nitroaromatic compounds—including 4-nitrophenol, 2,4-dinitrophenol, and PA—and relatively comprehensive explosive detection in all of the tests of IL-POSSs with nitroaromatic compounds thus far. Additionally, the data indicate that these two new ILs have great potential for the detection of explosives. Therefore, our work may provide new materials including ILs as fluorescent sensors in detecting nitroaromatic explosives. Full article

The use of polyhedral oligomeric silsesquioxanes (POSSs) for making polymer composites has grown exponentially since the last few years of the 20th century. In comparison with the other most commonly used fillers, POSSs possess the advantage of being molecules. Thus, this allows us to combine their nano-sized cage structures, which have dimensions that are similar to those of most polymer segments and produce a particular and exclusive chemical composition. These characteristics linked with their hybrid (inorganic–organic) nature allow researchers to modify POSS according to particular needs or original ideas, before incorporating them into polymers. In this present study, we first start with a brief introduction about the reasons for the rediscovery of these nanoparticles over the last 25 years. Starting from the form of POSS that is most widely used in literature (octaisobutyl POSS), this present study aims to evaluate how the reduction of symmetry through the introduction of organic groups favors their dispersion in polystyrene matrix without compromising their solubility. Full article

In acidic conditions, mesoporous molecular sieves SBA-15 and SBA-15-SH were synthesized. Structural characterization was carried out by powder X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ¹³C CP MAS-NMR, ²⁹Si CP MAS-NMR and nitrogen adsorption–desorption (BET). The results showed that in SBA-15-SH, the direct synthesis method made the absorption peak intensity weaker than that of SBA-15, while the post-grafted peak intensity did not change. Their spectra were different due to the C-H stretching bands of Si-O-Si and propyl groups. But their structure was still evenly distributed and was still hexangular mesoporous structure. Their pore size increased, and the H-SBA-15-SH had larger pore size. The adsorption of ammonia-nitrogen by molecular sieve was affected by the relative pressure and the concentration of ammonia-nitrogen, in which the adsorption capacity of G-SBA-15-SH was the largest and the adsorption capacity of SBA-15 was the smallest. Full article

One of the historical problems of medicine is that often, diagnosis and therapy do not interface, at best. Moreover, especially in some areas, such as oncology, the stress for the organism during the two phases (diagnosis and therapy) can become excessive, and be fatal to the success of the treatment. The extraordinary progress of nanotechnology in the last 25 years has offered the opportunity to build a nanoplatform able to ferry drugs, and loads onto them both imaging and therapeutic functions, thus creating nanosystems capable of diagnosis, drug delivery, and monitoring of therapeutic response. The purpose of this unusual, and up to recent times, unimaginable, marriage between diagnosis and therapeutics is the reaching of protocols more specific to individuals. The dual use of particles/device lead to a personalized medicine. Due to their biocompatibility, versatility, physical and chemical resistance, and ability to be functionalized, silica nanoparticles and polysiloxanes are the heart and the shield of this nanoplatform, respectively. In this short review, I analyze the applications of these silicon-based materials in the field of controlled drug delivery. Full article

In this work, new phenol-based materials have been synthesized by the sol-gel method, in which different amounts of the phenolic antioxidant chlorogenic acid (CGA) (from 5 wt % to 20 wt %) were embedded in two different silica matrices: pure silica and silica-based hybrids materials, containing 50 wt % of polyethylene glycol (PEG). The incorporation of CGA in different sol-gel matrices might protect them from degradation, which could cause the loss of their properties. The two series of materials were chemically characterized by Fourier transform infrared (FTIR) spectroscopy. In addition, the thermal behavior of both series of materials containing CGA was studied by thermogravimetry under both air and inert N₂ flowing gas atmosphere. The bioactivity was evaluated by soaking the synthesized hybrids in a simulated body fluid, showing that the bioactivity of the silica matrix is not modified by the presence of PEG and CGA. Full article

Polydimethylsiloxane (PDMS) polymers are extensively used in a wide range of research and industrial fields, due to their highly versatile chemical, physical, and biological properties. Besides the different two-dimensional PDMS formulations available, three-dimensional PDMS foams have attracted increased attention. However, as-prepared PDMS foams contain residual unreacted low molecular weight species that need to be removed in order to obtain a standard and chemically stable material for use as a scaffold for different decorating agents. We propose a cleaning procedure for PDMS foams obtained using a sugar templating process, based on the use of two different solvents (hexane and ethanol) as cleaning agents. Thermogravimetry coupled with Fourier Transform Infrared Spectroscopy (TG-FTIR) for the analysis of the evolved gasses was used to characterize the thermal stability and decomposition pathway of the PDMS foams, before and after the cleaning procedure. The results were compared with those obtained on non-porous PDMS bulk as a reference. Micro-CT microtomography and scanning electron microscopy (SEM) analyses were employed to study the morphology of the PDMS foam. The thermogravimetric analysis (TGA) revealed a different thermal behaviour and crosslinking pathway between bulk PDMS and porous PDMS foam, which was also influenced by the washing process. This information was not apparent from spectroscopic or morphological studies and it would be very useful for planning the use of such complex and very reactive systems. Full article

Hyperbranched siloxane-based polymers with ultra-high molecular weight were synthesized by the Piers–Rubinsztajn reaction between octakis(dimethylsiloxy) octasilsesquioxane with different dialkoxysilanes, using tris(pentafluorophenyl) borane as the catalyst. The origin of the high molecular weight is explained by the high reactivity of the catalyst and strain energy of isolated small molecule in which all eight silane groups close into rings on the sides of a single cubic cage. The structural tuneability was further demonstrated by use of methyl(3-chloropropyl)diethoxysilane, which generates a polymer with similar ultra-high molecular weight. Introduction of phosphonate groups through the chloropropyl sites later leads to functionalized polymers which can encapsulate various transition metal nanoparticles. Full article

Six liquid branched poly(methylhydrosiloxanes) of new random structures (PMHS-Q), containing quadruple branching units SiO_4/2 (Q), both MeHSiO (D^H) and Me₂SiO (D) chain building units (or only mers MeHSiO), and terminal groups Me₃SiO_0.5 (M) were prepared by a hydrolytic polycondensation method of appropriate organic chlorosilanes and tetraethyl ortosilicate (TEOS), in diethyl ether medium at temperature below 0 °C. Volatile low molecular weight siloxanes were removed by a vacuum distillation at 150–155 °C. Yields of PMHS-Q reached from 55–69 wt%. Their dynamic viscosities were measured in the Brookfield HBDV+IIcP cone-plate viscometer and ranged from 10.7–13.1 cP. Molecular weights (MW) of PMHS-Q (M_n = 2440–6310 g/mol, M_w = 5750–10,350 g/mol) and polydispersities of MW (M_w/M_n = 2.0–2.8) were determined by a size exclusion chromatography (SEC). All polymers were characterized by FTIR, ¹H- and ²⁹Si-NMR, and an elemental analysis. A microstructure of siloxane chains was proposed on a basis of ²⁹Si-NMR results and compared with literature data. Full article

A high performance ladder-like structured methacrylate siloxane hybrid material (LMSH) was fabricated via simple hydrolytic sol–gel reaction, followed by free-radical polymerization. A structurally ordered siloxane backbone, the ladder-like structure, which is an essential factor for high performance, could be achieved by a short period of sol–gel reaction in only 4 h. This results in superior optical (Transmittance > 90% at 550 nm), thermal (T_{5 wt % decomposition} > 400 $℃$ ), mechanical properties(elastic recovery = 0.86, hardness = 0.6 GPa) compared to the random- and even commercialized cage-structured silsesquioxane, which also has ordered structure. It was investigated that the fabricated ladder-like structured MSH showed the highest overall density of organic/inorganic co-networks that are originated from highly ordered siloxane network, along with high conversion rate of polymerizable methacrylate groups. Our findings suggest a potential of the ladder-like structured MSH as a powerful alternative for the methacrylate polysilsesquioxane, which can be applied to thermally stable and flexible optical coatings, even with an easier and simpler preparation process. Full article

Amphiphilic surfaces are particularly effective at inhibiting the adhesion of microorganisms (bacteria, cells, microalgae, etc.) in liquid media. The aim of this study is to determine the best hydrophilic linker to promote bonding between poly(ethylene glycol) (PEG) as a hydrophilic additive and poly(dimethyl siloxane) (PDMS) as the hydrophobic matrix. Various parameters have been studied (molecular weight, linker type, and polymer end-group), as well as the efficiency of the linking, the capacity of PEG to access to the surface of the film, and overall film homogeneity. According to the results, a PDMS linker paired with a PEG moiety allows for compatibilization of the compounds during cross-linking. This compatibilization seems to provide a good bonding with the matrix and a good surface access to the hydrophilic moiety. Therefore, this structure comprising a linking function attached to the PDMS–PEG copolymer has high potential as a non-releasable additive for amphiphilic coating applications. Full article

The influence of roughness and the way it affects the adhesion properties and surface free energy (SFE) of polysiloxanes hydrophobised basalt fibres–reinforced cement mortars were determined in this article. The physical properties of mortars were investigated in the experimental part, which also explored the impact of hydrophobisation and basalt fibres (BF) addition on SFE, frost resistance, contact angle (CA), and roughness. A device capable of calculating all parameters was used to indicate the surface roughness and 3D topography. Prior to and after conducting surface and weight hydrophobisation, the contact angle of mortars was specified. Subsequently, it was used for carrying out SFE calculation by means of Neumann’s method, enabling us to characterize the adhesion properties and wettability of mortars. The research indicated that the surface roughness was substantially decreased, in turn raising the frost resistance. The corrosion resistance drops when the surface roughness, water absorption, and number of fibres in the mortar increase. The SEM images presenting the structure of polysiloxane coating and mortars were provided. Full article

Ceramizable silicone rubber (MVQ)/halloysite (HNT) composites were fabricated by incorporation of three different borates, including sodium tetraborate decahydrate, ammonium pentaborate, and zinc borate into MVQ matrix, respectively. The composites without any borates were also prepared as control. The effect of the borates on the mechanical and electrical properties of MVQ/HNT composites was investigated. The ceramic residues were obtained from the decomposition of the composites after sintering at 1000 °C. The effect of the borates on the linear shrinkage, weight loss, and flexural and impact strength of the residues was also studied. The fracture surfaces of the composites and their corresponding residues were observed by SEM. The proposed ceramizable mechanism of the composites by incorporation of different borates was revealed by XRD analysis. Full article