Search Results (15)

With the rapid advancement of electronic devices toward higher frequencies, faster speeds, increased integration, and miniaturization, the resulting elevated operating temperatures pose significant challenges to the performance and longevity of electronic components. These developments have intensified the demand for high-performance thermal interface materials (TIMs). Conventional silicone rubber-based TIMs often suffer from silicone oil-bleeding and the volatilization of low-molecular-weight siloxanes under elevated temperatures and mechanical stress. The release of these volatile organic compounds can lead to their deposition on circuit boards and electronic components, causing signal interference or distortion in optical and electronic systems, ultimately compromising device functionality. Additionally, the intrinsic thermal conductivity of traditional TIMs is insufficient to meet the escalating demands for efficient heat dissipation. To overcome these limitations, this study introduces a novel, non-silicone TIM based on a calcium ion-crosslinked sodium alginate matrix, prepared via ion-exchange curing. This bio-derived polymer matrix serves as an environmentally benign alternative to silicone rubber. Furthermore, a brush-coating technique is employed to induce the oriented alignment of boron nitride (BN) fillers within the alginate matrix. Experimental characterization reveals that this aligned microstructure markedly enhances the thermal conductivity of the composite, achieving a value of 7.87 W·m⁻¹·K⁻¹. The resulting material also exhibits outstanding thermal and mechanical stability, with no observable leakage or condensate formation under high-temperature and high-pressure conditions. This work offers a new design paradigm for environmentally friendly, high-performance TIMs with considerable potential for advanced electronic and optoelectronic applications. Full article

Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products. Full article

Wastewater treatment from oil, oil products and organic mixtures is a very relevant topic that can be successfully utilized to solve problems of severe environmental pollution, such as oil spills, industrial oily wastewater discharges and water treatment in the water treatment process. In this work, we have developed new superhydrophobic magnetic polyurethane (PU) sponges, functionalized with reduced graphene oxide (RGO), MgFe₂O₄ nanoparticles, and silicone oil AS 100 (SO), as a selective and reusable sorbent for the purification and separation of wastewater from oil and organic solvents. The surface morphology and wettability of the sponge surface were characterized by scanning electron microscopy (SEM) and a contact angle analysis system, respectively. The results showed that the obtained PU sponge PU/RGO/MgFe₂O₄/SO had excellent mechanical and water-repellent properties, good reusability (lasted more than 20 cycles), as well as fast (immersion time 20 s) and excellent absorption capacity (16.61–44.86 g/g), and additional good magnetic properties, which made it easy to separate the sponge from the water with a magnet. The presence of RGO in the composition of the nanomaterial improves the separating and cleaning properties of the materials and also leads to an increase in the absorption capacity of oil and various organic solvents. The synthesized PU sponge has great potential for practical applications due to its facile fabrication and excellent oil–water separation properties. Full article

The discharge and accumulation of coal-based solid waste have caused great harm to the ecological environment recently. Coal-based solid wastes, such as coal gangue and fly ash, are rich in valuable components, such as rare earth elements (REY), silicon dioxide, alkali metal oxides, and transition metal oxides, which can be used to synthesize various functional Si-based porous materials. This article systematically summarizes the physicochemical characteristics and general processing methods of coal gangue and fly ash and reviews the progress in the application of porous materials prepared from these two solid wastes in the fields of energy and environmental protection, including the following: the adsorption treatment of heavy metal ions, ionic dyes, and organic pollutants in wastewater; the adsorption treatment of CO₂, SO₂, NO_x, and volatile organic compounds in waste gas; the energy regeneration of existing resources, such as waste plastics, biomass, H₂, and CO; and the preparation of Li–Si batteries. Combining the composition, structure, and action mechanism of various solid-waste-based porous materials, this article points out their strengths and weaknesses in the above applications. Furthermore, ideas for improvements in the applications, performance improvement methods, and energy consumption reduction processes of typical solid-waste-based porous materials are presented in this article. These works will deepen our understanding of the application of solid-waste-based porous materials in wastewater treatment, waste gas treatment, energy regeneration, and other aspects, as well as providing assistance for the integration of new technologies into solid-waste-based porous material preparation industries, and providing new ideas for reducing and reusing typical Chinese solid waste resources. Full article

Photocatalytically active silicon carbide (SiC)-based mesoporous layers (pore sizes between 5 and 30 nm) were synthesized from preceramic polymers (polymer-derived ceramic route) on the surface and inside the pores of conventional macroporous α-alumina supports. The hybrid membrane system obtained, coupling the separation and photocatalytical properties of SiC thin films, was characterized by different static and dynamic techniques, including gas and liquid permeation measurements. The photocatalytic activity was evaluated by considering the degradation efficiency of a model organic pollutant (methylene blue, MB) under UV light irradiation in both diffusion and permeation modes using SiC-coated macroporous supports. Specific degradation rates of 1.58 × 10⁻⁸ mol s⁻¹ m⁻² and 7.5 × 10⁻⁹ mol s⁻¹ m⁻² were obtained in diffusion and permeation modes, respectively. The performance of the new SiC/α-Al₂O₃ materials compares favorably to conventional TiO₂-based photocatalytic membranes, taking advantage of the attractive physicochemical properties of SiC. The developed synthesis strategy yielded original photocatalytic SiC/α-Al₂O₃ composites with the possibility to couple the ultrafiltration SiC membrane top-layer with the SiC-functionalized (photocatalytic) macroporous support. Such SiC-based materials and their rational associations on porous supports offer promising potential for the development of efficient photocatalytic membrane reactors and contactors for the continuous treatment of polluted waters. Full article

Herein, we encapsulated modified silicon carbide nanoparticles utilizing a metal–organic backbone. E-SiC-FeZnZIF composites were successfully prepared via Fe doping. The catalysis activity of this bifunctional composite material was evaluated by the degradation of tetracycline (THC) and carbamazepine (CBZ) and the reduction of carbon dioxide (CO₂). Nano SiC has received widespread attention in advanced oxidation applications, especially in the catalytic activation of peroxymonosulfate (PMS). However, the inferior activity of SiC has severely restricted its practical use. In this study of dual functional composite materials, nano SiC was firstly etched under aqueous alkali. Then, zeolite imidazolate frame-8 (ZIF-8) was used for immobilization. The filling of the etched nano SiC with FeZnZiF was confirmed by SEM, XRD, FTIR, BET, and XPS analyses. In addition, E-SiC-FeZnZIF exhibited excellent catalytic activation of peroxymonosulfate (PMS) to oxidize water pollutants, which can degrade tetracycline hydrochloride (THC), achieving a removal rate of 72% within 60 min. Moreover, E-SiC-FeZnZIF exhibited a relatively high CO₂ reduction rate with H₂O. The yields of CO and CH₄ were 0.085 and 0.509 μmol g⁻¹, respectively, after 2 h, which are higher than that of 50 nm of commercial SiC (CO: 0.084 μmol g⁻¹; CH₄: 0.209 μmol g⁻¹). This work provides a relatively convenient synthesis path for constructing metal skeleton composites for advanced oxidation and photocatalytic applications. This will have practical significance in protecting water bodies and reducing CO₂, which are vital not only for maintaining the natural ecological balance and negative feedback regulation, but also for creating a new application carrier based on nano silicon carbide. Full article

Two different types of graphene materials were used as functional nanofillers for the mechanical and tribological improvement of silicon carbide/graphene nanocomposites. On the one hand is thermally reduced graphite oxide (TRGO) reduced at three different temperatures, and on the other hand is graphene made of three different organic precursors, which were directly coated on silicon carbide (SiC) platelets (GSiC). Additionally, benchmark materials were also used as carbon fillers. The SiC/graphene nanocomposites with 2 wt% filler content were manufactured by pressureless sintering (PLS). Some composites were produced with higher graphene contents of 4% and 8% and sintered by spark plasma sintering (SPS). Microstructural analyses were conducted using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Underwater lubrication, the SP sintered TRGO and GSiC materials with high graphene content have shown the most promising tribological performance. Furthermore, the reduced size of the homogeneously distributed nanoparticles promotes the formation of surface states, which improve the friction and wear properties. Full article

Hybrid phenol-formaldehyde (PF) resins represent one of the most important niche groups of binding systems for composites. New industrial needs, environmental requirements, and price fluctuations have led to further research on materials with enhanced mechanical and thermal properties. The preparation of novel hybrid materials can be achieved by inclusion of various elements or functional groups in the organic polymer phenolic framework. Herein, we report the synthesis and characterization of a PF-based hybrid material with different nanoscale silicone species and ZnAl-layered double hydroxide (LDH). The main goals of this study were to improve the synthetic pathways of hybrid resin, as well as to prepare granulated composite materials and test samples and determine their characterization. Added inorganic species increased the glass-transition temperature by a minimum of 8 °C, which was determined using differential scanning calorimetry (DSC). Rheological properties (melting viscosity and flow distance) of the hybrid resin were measured. The homogeneity of distribution of added species across the organic matrix was evaluated with scanning electron microscopy (SEM). With synthesized new hybrid-binding systems, we prepared different granulated composite materials and evaluated them with the measurements of rheological properties (flow curing characteristics). Tensile strength of samples, prepared from granulated composite material, improved by more than 5%. Full article

A novel Co-based organic frameworks/carbon nanotubes/silicon dioxide (Co-MOF/CNTs/SiO₂)-modified Au electrode was fabricated and taken as a platform for gallic acid (GA) detection. The composite combined the advantages of Co-MOF, CNTs and SiO₂, and higher electrochemical response of Co-MOF/CNTs/SiO₂-modified electrode indicated that the composite material exhibited satisfied the catalytic activity towards GA. Moreover, the electrochemical oxidation process of GA was deeply investigated on the surface of electrode based on computational investigations. Hirshfeld charges and condensed Fukui functions of each atom in GA were calculated. Besides, the catalysis of Co-MOF to GA was further investigated based on density functional theory. The quantitative determination of GA was carried out and showed a linear range between 0.05–200 μM, with low limit of detection. The sensitivity value of the self-assembled electrochemical sensor was calculated to be 593.33 μA cm⁻² mM⁻¹, and the selectivity, reproducibility and stability of the gallic acid sensor were also confirmed in the study. Full article

The effect of multiwall carbon nanotubes (MWCNTs) and magnesium oxide (MgO) on the thermal conductivity of MWCNTs and MgO-reinforced silicone rubber was studied. The increment of thermal conductivity was found to be linear with respect to increased loading of MgO. In order to improve the thermal transportation of phonons 0.3 wt % and 0.5 wt % of MWCNTs were added as filler to MgO-reinforced silicone rubber. The MWCNTs were functionalized by hydrogen peroxide (H₂O₂) to activate organic groups onto the surface of MWCNTs. These functional groups improved the compatibility and adhesion and act as bridging agents between MWCNTs and silicone elastomer, resulting in the formation of active conductive pathways between MgO and MWCNTs in the silicone elastomer. The surface functionalization was confirmed with XRD and FTIR spectroscopy. Raman spectroscopy confirms the pristine structure of MWCNTs after oxidation with H₂O₂. The thermal conductivity is improved to 1 W/m·K with the addition of 20 vol% with 0.5 wt % of MWCNTs, which is an ~8-fold increment in comparison to neat elastomer. Improved thermal conductive properties of MgO-MWCNTs elastomer composite will be a potential replacement for conventional thermal interface materials. Full article

In the last decade, perovskite photovoltaics gained popularity as a potential rival for crystalline silicon solar cells, which provide comparable efficiency for lower fabrication costs. However, insufficient stability is still a bottleneck for technology commercialization. One of the key aspects for improving the stability of perovskite solar cells (PSCs) is encapsulating the photoactive material with the hole-transport layer (HTL) with low gas permeability. Recently, it was shown that the double HTL comprising organic and inorganic parts can perform the protective function. Herein, a systematic investigation and comparison of four double HTLs incorporating polytriarylamine and thermally evaporated transition metal oxides in the highest oxidation state are presented. In particular, it was shown that MoO_x, WO_x, and VO_x-based double HTLs provided stable performance of PSCs for 1250 h, while devices with NbO_x lost 30% of their initial efficiency after 1000 h. Additionally, the encapsulating properties of all four double HTLs were studied in trilayer stacks with HTL covering perovskite, and insignificant changes in the absorber composition were registered after 1000 h under illumination. Finally, it was demonstrated using ToF-SIMS that the double HTL prevented the migration of perovskite volatile components within the structure. Our findings pave the way towards improved PSC design that ensures their long-term operational stability. Full article

Composite polymer electrolytes (CPEs) incorporate the advantages of solid polymer electrolytes (SPEs) and inorganic solid electrolytes (ISEs), which have shown huge potential in the application of safe lithium-metal batteries (LMBs). Effectively avoiding the agglomeration of inorganic fillers in the polymer matrix during the organic–inorganic mixing process is very important for the properties of the composite electrolyte. Herein, a partial cross-linked PEO-based CPE was prepared by porous vinyl-functionalized silicon (p-V-SiO₂) nanoparticles as fillers and poly (ethylene glycol diacrylate) (PEGDA) as cross-linkers. By combining the mechanical rigidity of ceramic fillers and the flexibility of PEO, the as-made electrolyte membranes had excellent mechanical properties. The big special surface area and pore volume of nanoparticles inhibited PEO recrystallization and promoted the dissolution of lithium salt. Chemical bonding improved the interfacial compatibility between organic and inorganic materials and facilitated the homogenization of lithium-ion flow. As a result, the symmetric Li|CPE|Li cells could operate stably over 450 h without a short circuit. All solid Li|LiFePO₄ batteries were constructed with this composite electrolyte and showed excellent rate and cycling performances. The first discharge-specific capacity of the assembled battery was 155.1 mA h g⁻¹, and the capacity retention was 91% after operating for 300 cycles at 0.5 C. These results demonstrated that the chemical grafting of porous inorganic materials and cross-linking polymerization can greatly improve the properties of CPEs. Full article

A comparative study of the microscopic morphology and chemical characteristics of spicules of Hexactinellids (Hexactinellida) with different structural features of the skeletons, as well as the freshwater Baikal sponge belonging to the class of common sponges (Demospongia), was carried out. The trace element composition of sponge spicules was determined by X-ray fluorescence spectrometry. The spicules of siliceous sponges contain many elements, arranged in decreasing order of concentration: Si, Ca, Fe, Cl, K, Zn, and others. It was shown that the surface layer of sea sponges contains mainly carbon (C), oxygen (O), and to a lesser extent nitrogen (N), silicon (Si), and sodium (Na). The spicules of the studied siliceous sponges can be divided into two groups according to the phase composition, namely one containing crystalline calcium compounds and one without them. Analysis of infrared absorption spectra allows us to conclude that the sponges Euplectella aspergillum, E. suberia and Dactylocalyx sp. contain silica partially bound to the organic matrix, while the silica skeleton of the sponges of the other group (Schulzeviella gigas, Sericolophus sp., Asconema setubalense, Sarostegia oculata, Farrea sp. and Lubomirskia baicalensis sp.) practically does not differ from the precipitated SiO₂. This comparative study of the chemical composition of the skeletons of marine Hexactinellids and common freshwater sponge allows us to conclude that there are no fundamental differences in the chemical composition of spicules, and all of them can be used as a starting material for creating new composite silicon–organic functional materials. Full article

Hybrid particles consisting of an organic polymer and silica or polyorganosiloxanes are interesting building blocks for nanocomposites. The synthesis of such particles typically requires multiple reaction steps involving the formation of polymer colloids and the subsequent deposition of silicon-containing material either inside or on the surface of these colloids, or vice versa. In 2014, we reported a facile method for the one-pot synthesis of sub-micron sized hybrid particles based on simultaneous sol-gel conversion of organotrimethoxysilanes and emulsion polymerization of a vinylic monomer, illustrated by the synthesis of polystyrene-polyphenylsiloxane particles from the monomers styrene and phenyltrimethoxysilane (Segers et al (2014). In this process, the required surface active species was formed in situ through hydrolytic conversion of phenyltrimethoxysilane to phenylsilanolate oligomers. Introduction of thiol groups in such hybrid particles should yield particles suited for functionalization with small metal nanoparticles, e.g., Au. Here, we present the synthesis of thiol-containing hybrid particles consisting of poly(3-mercaptopropyl)siloxane and polystyrene using the one-pot synthesis method based on simultaneous conversion of (3-mercaptopropyl)trimethoxysilane and styrene. We prepared particles from different volume ratios of (3-mercaptopropyl)trimethoxysilane and styrene, ranging from 1:99 to 80:20. The resulting spherical hybrid particles displayed different sizes, compositions, and architectures (including core-shell), which were studied in detail using scanning electron microscopy, thermogravimetric analysis, and scanning transmission electron microscopy combined with energy dispersive x-ray spectroscopy. The composition of these particles, and consequently the number of thiol groups available for further functionalization such as metal anchoring, was tunable. Full article

Hybrid materials of electrically conducting polymers and inorganic semiconductors form an exciting class of functional materials. To fully exploit the potential synergies of the hybrid formation, however, sophisticated synthetic methods are required that allow for the fine-tuning of the nanoscale structure of the organic/inorganic interface. Here we present the photocatalytic deposition of a conducting polymer (polyaniline) on the surface of silicon carbide (SiC) nanoparticles. The polymerization is facilitated on the SiC surface, via the oxidation of the monomer molecules by ultraviolet-visible (UV-vis) light irradiation through the photogenerated holes. The synthesized core–shell nanostructures were characterized by UV-vis, Raman, and Fourier Transformed Infrared (FT-IR) Spectroscopy, thermogravimetric analysis, transmission and scanning electron microscopy, and electrochemical methods. It was found that the composition of the hybrids can be varied by simply changing the irradiation time. In addition, we proved the crucial importance of the irradiation wavelength in forming conductive polyaniline, instead of its overoxidized, insulating counterpart. Overall, we conclude that photocatalytic deposition is a promising and versatile approach for the synthesis of conducting polymers with controlled properties on semiconductor surfaces. The presented findings may trigger further studies using photocatalysis as a synthetic strategy to obtain nanoscale hybrid architectures of different semiconductors. Full article