Search Results (160)

Waste plastic aggregate (WPA) is a promising recycled material for asphalt mixtures, but its polymeric surface can weaken binder adhesion and increase moisture-related damage, even in SBS-modified systems. Therefore, a clear need exists to identify anti-stripping agents that are compatible with WPA, rather than simply increasing WPA content in asphalt mixtures. This study evaluates the interfacial and mixture-scale performance of SBS-modified asphalt mixtures containing two WPA types, namely coarse WPA and fine WPA, treated with three liquid anti-stripping agents: amine-based agent (AS-Am), organosilane coupling-type adhesion promoter (AS-OS), and ester/surfactant-based wetting agent (AS-Es). The novelty of this study lies in selecting the anti-stripping system based on WPA–binder adhesion compatibility and validating it through moisture, rutting, rheological, and fracture performance. Binder bond strength, tensile bond strength, shear bond strength, indirect tensile strength/tensile strength ratio (ITS/TSR), Hamburg wheel tracking (HWT), multiple stress creep recovery (MSCR), and semi-circular bending (SCB) tests were conducted. AS-OS showed the best overall performance. It increased binder bond strength (BBS) by 52.8% for coarse WPA and 61.5% for fine WPA, while the optimum 0.5% dosage improved tensile bond strength by 81.0% and 97.2%, respectively. AS-OS also increased shear strength by 58.8–68.3% and improved TSR to 89.0% and 86.2%. In HWT, C-OS and F-OS reduced final rut depth by 44.0% and 45.8%, respectively. SCB results further showed higher fracture work, especially for F-OS. The findings indicate that proper anti-stripping chemistry is essential for durable WPA–SBS asphalt mixtures. Full article

Surface modification of zinc oxide nanoparticles (ZnO NPs) with organosilane capping agents represents an effective strategy to control their physicochemical and biological properties. In this work, we report for the first time the use of halogenosilanes, namely (3-chloropropyl)trimethoxysilane (CPTMS), (3-bromopropyl)trimethoxysilane (BPTMS) and (3-iodopropyl)trimethoxysilane (IPTMS), for the surface functionalization of ZnO NPs obtained by chemical precipitation. Structural and morphological characterization (PXRD, TEM, SEM-EDX and FTIR) confirmed successful surface modification and revealed a significant particle size reduction from ~31 nm for unmodified ZnO to ~8 nm for BPTMS-modified ZnO (ZnO_b). The biological evaluation showed that halogenosilane-modified ZnO NPs exhibit enhanced cytotoxic activity against prostate cancer cell lines (PC3 and 22Rv1), with ZnO_b displaying the highest activity, likely associated with improved cellular uptake and increased reactive oxygen species (ROS) generation. In contrast, antimicrobial assays revealed only moderate bactericidal effects against Escherichia coli and Staphylococcus aureus at relatively high concentrations (≥1250 µg mL⁻¹), while no significant activity was observed against Pseudomonas aeruginosa, Burkholderia contaminans or Candida spp., within the tested range. These findings suggest that halogenosilane functionalization modulates the biological profile of ZnO nanoparticles by enhancing anticancer effects while also influencing microbiocidal activity, highlighting the role of surface chemistry in tuning biological selectivity. The present study supports the concept that rational surface engineering of ZnO-based nanoplatforms can be exploited to favor tumor-targeted activity over broad-spectrum antimicrobial effects, providing new perspectives for the design of application-oriented nanomaterials. Full article

Bio-based polyurethane (PU) coatings offer sustainable alternatives to petrochemical coatings but often suffer from inferior mechanical performance, durability, and chemical resistance. This work addresses that challenge by integrating a trifunctional bio-based crosslinker (glycerol) and a silane-based additive (hexamethyldisilane (HMDS)) to simultaneously enhance structural robustness and hydrophobicity. Coatings were synthesized using a renewable soybean oil polyol (SOP), glycerol (5, 10, 15 and 20 wt.%), and methylene diphenyl diisocyanate (MDI), followed by the addition of HMDS (10, 20, 30, 40 and 50 wt.%). Mechanical tests identified 10 wt.% glycerol as the optimal content, yielding a maximum tensile strength of 47.18 MPa. Incorporating 10 wt.% HMDS into the optimized formulation greatly increased water contact angle (WCA, 95.76°) and chemical resistance with minimal loss of mechanical performance (38.19 MPa, tensile strength); higher HMDS loadings caused network disruption and reduced strength. Calorimetry and thermogravimetric analyses confirmed that the modified coatings retained high thermal stability. This synergistic crosslinker additive strategy produced a structurally robust, water-resistant bio-based coating, demonstrating a viable high-performance sustainable coating solution for industrial applications. Full article

Gas-phase thermal deposition was used to form three organosilane self-assembled monolayers on indium tin oxide (ITO) anodes: amine-terminated (NH₂SAM), methyl-terminated (CH₃SAM), and trifluoropropyl-terminated (F₃SAM). Surface characterisation using water contact angle goniometry, ultraviolet photoelectron spectroscopy, and atomic force microscopy was combined with green organic light emitting diode (OLED) fabrication and J–V–L measurements to determine how terminal group chemistry and deposition time affect device performance. F₃SAM increased the ITO work function from 3.72 to 4.47–4.72 eV, resulting in ultrasmooth surfaces (R_a = 0.20 nm) and a maximum luminescence of ~6000 cd m⁻², eleven times higher than bare ITO (540 cd m⁻²). CH₃SAM enhanced luminescence through surface passivation at 10 min (3374 cd m⁻²), but decreased quickly with extended deposition durations due to multilayer roughening. NH₂SAM reduced the work function to 3.42 eV and gradually decreased hole injection, resulting in a turn-on voltage of 10–11 V after 180 min. These results indicate that terminal group polarity and deposition duration are the two most important parameters in gas-phase SAM engineering of ITO anodes for OLEDs. Full article

The article deals with the study of stress corrosion cracking (SCC) of X70 steel using corrosion-mechanical testing that simulates the operating conditions of underground pipelines. The tests were carried out under cyclic four-point bending at stresses close to the yield point, in electrolytes with various hydrogen charging capacities. The following model environments were used: NS4 solution and citrate buffer (pH 5.5). Hydrogen charging was controlled by the addition of thiourea and by varying the potential. It was shown that microcracks initiated at corrosion defects (pits) and then emerged at the surface to form narrow cracks. The incubation period depends on the environment: under corrosive conditions it is approximately two times shorter than in the air. The size and nature of stress concentrators play a significant role: natural pits (~hundreds of μm) lead to crack formation within 24–28 days, whereas artificial holes (0.6–1 mm) lead to crack formation within 5–7 days. The effect of hydrogen was established: the acceleration is insignificant under moderate hydrogen charging, whereas the incubation period decreases sharply at high hydrogen charging. Critical hydrogen concentrations where its effect becomes significant were determined. Methods for inhibiting stress corrosion cracking by means of organosilicon films (vinyl- and aminosilanes, as well as their mixtures with inhibitors—benzotriazole and amines) were considered. The most effective composition is vinylsilane + benzotriazole: the time to crack initiation increases from 5 to 36 days, and the crack growth rate decreases. Full article

In this work, various types of organosilanes were introduced into Sn-Si oxide through a simple aerosol process to yield synthesis precursors. Then, a series of Sn-Beta zeolites were successfully synthesized using a hydrothermal method in the presence of fluoride. The influence of amine groups (A, 2A, and 3A), the length of branched chains present in the organosilanes, as well as the use of dipodal silanization agents (B2A) on the morphology, pore structure, acidic properties, coordination state, and content of Sn species in the obtained Sn-Beta zeolite samples was investigated. Compared to the organosilane-free Sn-Beta (crystal size: 1.3 μm; Si/Sn = 119; Lewis acid density: 77 μmol·g⁻¹), all monopodal organosilane-doped samples (Sn-Beta-A, -2A, and -3A) exhibited reduced crystal sizes (~0.9 μm) and increased specific surface areas (up to 502 m²·g⁻¹ for Sn-Beta-2A). UV–Vis spectroscopy showed that Sn-Beta-2A (containing two amine groups) achieved the highest optical bandgap (4.68 eV) and the strongest suppression of extra-framework SnO_x species (peak at ~269 nm), indicating the most isolated tetrahedral framework Sn⁴⁺ sites. This sample also delivered the highest Lewis acid density (225 μmol·g⁻¹) and the best catalytic performance in the Baeyer–Villiger oxidation of cyclohexanone (39% conversion, TON = 106) and 2-adamantanone (37% conversion, TON = 101). By contrast, the dipodal organosilane (B₂A) caused severe steric hindrance, yielding the lowest crystallinity (relative crystallinity 64%), Si/Sn ratio (158), Lewis acid density (38 μmol·g⁻¹), and catalytic activity, despite forming a nanoaggregate morphology with high mesoporosity (V meso = 0.20 cm³·g⁻¹). These quantitative results demonstrate that monopodal organosilanes with two amine groups optimally balance Sn incorporation and textural properties, whereas dipodal silanes hinder framework Sn entry. This study provides clear, numerically grounded guidelines for selecting organosilane functional groups to design high-performance Sn-Beta zeolites. Full article

This study evaluated the performance of a pilot unit for the combined removal of microplastics and total suspended solids at the municipal wastewater treatment plant of Mykonos, Greece. The pilot unit was installed downstream of the two-stage conventional activated sludge line and operated in semi-continuous mode to demonstrate its function under real effluent conditions. Across five experimental loops, influent microplastics concentrations ranged from 633 to 5843 microplastics/L, while effluent values were reduced to 96–263 microplastics/L, corresponding to an average removal efficiency of 86 ± 8%. In parallel, total suspended solids decreased by 95 ± 3%, turbidity by 93 ± 7%, and chemical oxygen demand by 70 ± 20%, while pH and conductivity remained stable. Influent water showed pronounced variability in chemical oxygen demand, total suspended solids, and turbidity due to irregular wastewater deliveries, yet the pilot consistently stabilized the effluent quality. A correlation analysis revealed strong associations between turbidity, total suspended solids, and chemical oxygen demand in the influent, while effluent data indicated close links between microplastics removal and particulate reduction. These findings confirm the robustness of the organosilane-based agglomeration process and highlight its potential as an advanced treatment stage to reduce MP emissions, improve effluent stability, and mitigate environmental risks in receiving environments such as the Mediterranean Sea. Full article

The growing demand for portable and wireless electronic devices, along with the necessity to reduce reliance on non-renewable energy sources, has driven the need for energy harvesting materials. Nanocomposites, combining a polymeric matrix and a high-performance dielectric ceramic phase, are a promising solution. In such systems, the design of a hybrid matrix–filler interface is critical for achieving desired properties. Here, nanocomposites (NCs) were prepared by adding various amounts of hydrothermally synthesized BaTiO₃ (BT) nanoparticles (NPs) to polydimethysiloxane (PDMS). To investigate hybrid interfaces, NPs were used either bare or surface-functionalized with two silanes, 3-glycidyloxypropyltrimethoxysilane (GPTMS) or 2-[acetoxy(polyethyleneoxy)propyl]triethoxysilane (APEOPTES). NC films (80–100 μm thick) were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), and thermogravimetric analysis (TGA). Dielectric properties and breakdown strength (E_BD) were measured, and the theoretical volumetric energy density was calculated as a function of the filler loading and functionalization. The results demonstrate that hybrid interface design is pivotal for enhancing dielectric performance in NCs. APEOPTES-functionalized NPs significantly improved the dielectric response at a low filler loading (3.5%vol.), increasing permittivity from 2.8 to 7.5, E_BD from 33.8 to 42.1 kV/mm and energy density from 30 to >100 mJ/cm³. These findings underscore that designing hybrid interfaces through NP functionalization provides an effective strategy to achieve superior dielectric performance in PDMS-based NCs, retaining the advantages of the elastomeric matrix by reducing the amount of ceramic fillers. Full article

In dynamic equilibria, benzylsilicon pyridine-2-olate (BnSi(pyO)₃, L) and benzaldehyde react with addition of the Si(pyO) moieties to the PhHC=O carbonyl group and formation of compounds BnSi(–O–C(H,Ph)–N^(2-pyridone))_x(pyO)_3−x (L’, L’’, and L’’’, for x = 1, 2, 3, respectively). Addition of CuCl to a solution containing L, L’, L’’, and L’’’ results in the formation of BnSi(pyO)₃CuCl (LCuCl), shifting the equilibrium towards L with liberation of benzaldehyde. In THF as a solvent, the reaction of L in the presence of excess CuCl affords the complex LCuClCuCl. Upon dissolving in chloroform, it transforms into LCuCl with precipitation of CuCl. The solid state structure of LCuClCuCl features both the monomeric complex with CuClCuCl pattern and a dimer thereof with CuClCu(Cl)₂CuClCu pattern and a central Cu₂Cl₂ four-membered ring. This dimer of LCuClCuCl is the first crystallographically characterized representative of this Cu(I)-only Cu₄Cl₄ motif. The reaction of LCuCl and silver tosylate (AgOTos) in THF affords LCuOTos with precipitation of AgCl, whereas LAgOTos was obtained from L and AgOTos. In the crystal structure, LAgOTos features tetracoordinate Ag(I) in a distorted tetrahedral AgN₃O coordination sphere and a short Ag···Si trans-annular contact (3.3245(7) Å). ¹⁰⁹Ag NMR spectroscopy indicates a change in the coordination in solution, with δ ¹⁰⁹Ag = +551 and +419 ppm in the solid and in CDCl₃ solution, respectively. In combination, ²⁹Si NMR spectroscopy indicates changes in the Si coordination sphere, with δ ²⁹Si = −74.2 and −66.5 ppm in the solid and in CDCl₃ solution, respectively. Conversion of LAgOTos with tetraethylammonium chloride results in the precipitation of AgCl with release of L. Full article

Hybrid silica xerogels functionalised with chlorinated organosilanes combine tunable porosity and surface chemistry, rendering them attractive for applications in sensing, membrane technology, and photonics. This study quantitatively investigates the thermal decomposition kinetics of organochlorinated xerogels and correlates with volatile compounds previously identified via Thermogravimetric Analysis (TGA) coupled to Fourier-Transform Infrared Spectroscopy (FT–IR) and Gas Chromatography coupled with Mass Spectrometry (GC–MS). The xerogels were synthesised via the sol–gel process using organochlorinated alkoxysilane precursors and yielded highly condensed nanostructures in which the precursor nature strongly influences the morphology and textural properties. In this study, the molar percentage of the organochlorinated compounds was fixed at 10%. Standard N₂ adsorption-desorption isotherm at 77 K revealed that increasing the precursor content systematically decreased the specific surface area and pore volume of the materials while promoting the formation of periodic domains, which are observed even at low organosilane molar percentages. Thermal characterisation via TGA/FT–IR/GC–MS revealed at least two main decomposition stages, with thermal stability following the order of 4–chlorophenyl > chloromethyl > 3–chloropropyl > 2–chloroethyl. This study focuses on kinetic and mechanistic insights in the thermal decomposition process through the Flynn–Wall–Ozawa isoconversional method and Criado master plots, using TGA/Differential Scanning Calorimetry (DSC) measurements under nitrogen at multiple heating rates (5, 10, 20, 30, and 40 K min⁻¹), which revealed activation energies ranging from 53 to 290 kJ mol⁻¹. Demonstrating that the chlorinated organosilane precursor directly controls both the textural properties and thermal behaviour of the resulting silica materials, with aromatic groups providing superior thermal stability compared to aliphatic chains. These quantitative kinetic insights provide a predictive framework for designing thermally stable hybrid materials while ensuring safe processing conditions to prevent hazardous volatile release. Full article

Polyvinyl alcohol (PVA) is increasingly encountered in wastewater, yet reliable quantification and effective removal remain challenging. A colorimetric method for PVA quantification was validated, demonstrating excellent linearity and recoveries of 100.6 ± 2.8%. Limits were established at a limit of detection (LOD) of 1.28 mg/L and a limit of quantification (LOQ) of 1.8 mg/L. Accuracy was influenced by the PVA type, with errors reaching up to 42% due to variations in molecular weight and degree of hydrolyzation affecting the color complex. Consequently, polymer-specific calibration is advised. Analytical precision required strict temperature control and exact reaction times, and potential matrix interferences in wastewater should be assessed prior to application. PVA removal was evaluated using an AOP process based on hydrogen peroxide (H₂O₂) and UV-C irradiation. Increasing the H₂O₂/PVA ratio beyond 1:1 provided only marginal improvements, whereas increasing the UV-C dose was more impactful. A 1:1 H₂O₂/PVA ratio was sufficient even at PVA concentrations up to 5 g/L. Optimal UV-C doses were 7.5–12.5 kJ/m²; higher doses yielded only marginal additional removal. The colorimetric method was suitable for laboratory trials. A pilot-scale treatment of industrial wastewater applied microplastic agglomeration with organosilanes followed by granular activated carbon (GAC) treatment, which reduced PVA from an average of 24.2 mg/L to 7.4 mg/L, achieving ~65% removal, while microplastic removal reached 99.1%. Full article

Transparent PDLLA/silica hybrid films were prepared via a sol–gel process using organosilane-terminated PDLLA, and two structural motifs—graft-type and 3D-network hybrids—were systematically compared. Dynamic mechanical analysis (DMA) revealed that silica incorporation significantly restricted polymer chain mobility, increasing the onset temperature of the storage modulus from 33.9 °C for neat PDLLA to 41.5 °C and 50.3 °C for the 15 and 20 wt% graft-type hybrids, respectively. Thermogravimetric analysis (TGA) confirmed silica contents of 8.8–18.5 wt% and showed that the 10% weight-loss temperature increased by ~60 °C relative to neat PDLLA, with improvements primarily governed by silica content rather than hybrid topology. Small-angle X-ray scattering (SAXS) demonstrated uniform nanoscale dispersion with inter-domain distances of ~60–65 nm and no domain coarsening; combining these distances with the PDLLA end-to-end distance (R₀ ≈ 24–30 nm) yielded effective silica domain sizes of 30–35 nm. Porod analysis distinguished diffuse interfaces in graft-type hybrids from more correlated structures in network-type hybrids. Optically, the hybrids maintained high transparency (>90% at 400 nm) up to 18 wt% silica, while the Abbe number increased from 55 (neat PDLLA) to 73 (20 wt%). These findings provide quantitative insight into how nanoscale silica organization dictates thermomechanical, thermal, and optical behavior in PDLLA hybrids, extending the understanding established by earlier studies and supporting the continued development of PDLLA/silica hybrid materials. Full article

Salt efflorescence is always a main barrier for pottery cultural relic conservation. This study presents an innovative two-step process for enhancing the reinforced strength of efflorescence pottery. The first step involves forming a cross-linked mesh structure on the weathered surfaces using ethyl orthosilicate hydrolysate as an organic reinforcement material. In the second step, a two-component inorganic reinforcement material is developed to transform the destructive salt into a filling reinforcement material. The reinforcement pottery was comparatively investigated by XRD, color difference analysis, penetration depth measurements, mechanical strength tests, permeability assessment, and surface morphology characterization. The results demonstrate that the optimized reinforcement material exhibits high water permeability (up to 2.5 cm in penetration depth), stable color variation (ΔE up to 1.44), and excellent mechanical properties (17.01 MPa compressive strength and 2.66 MPa flexural strength). This work presents a promising technique for enhancing the structural interlocking between reinforcement pottery, which is crucial for mitigating dominant salt damage, and suggests an effective strategy that is applicable to the protection of cultural relics. Full article

This pilot study investigated an automated pilot plant for removing microplastics (MPs) from industrial wastewater that are generated during packaging production. MP removal is based on organosilane-induced agglomeration-fixation (clump & skim technology) followed by separation. The wastewater had high MP loads (1725 ± 377 mg/L; 673 ± 183 million particles/L) and an average COD of 7570 ± 1339 mg/L. Over 25 continuous test runs, the system achieved consistent performance, removing an average of 97.4% of MPs by mass and 99.1% by particle count, while reducing the COD by 78.8%. Projected over a year, this equates to preventing 1.7 tons of MPs and 6 tons of COD from entering the sewage system. Turbidity and photometric TSS measurements proved useful for process control. The approach supports water reuse—with water savings up to 80%—and allows recovery of agglomerates for recycling and reuse. Targeting pollutant removal upstream at the source provides multiple financial and environmental benefits, including lower overall energy demands, higher removal efficiencies, and process water reuse. This provides financial and environmental incentives for industries to implement sustainable solutions for pollutants and microplastic removal. Full article

Nanoclays have gained attention in biological applications due to their biocompatibility, low toxicity, and cost-effectiveness. Layered double hydroxides (LDHs) are synthetic nanoclays that have been used as adjuvants and antigen carriers in nanovaccines developed through passive bioconjugation. However, performing active bioconjugation to bind antigens covalently and generate subunit nanovaccines remains unexplored. In this study, we investigated the synthesis, functionalization, and active conjugation of LDH nanoparticles to produce subunit nanovaccines with peptides from SARS-CoV-2. The synthesis of Mg-Al LDHs via a coprecipitation and hydrothermal treatment rendered monodisperse particles averaging 100 nm. Their functionalization with (3-aminopropyl)triethoxysilane was better than it was with other organosilanes. Glutaraldehyde was used as a linker to bind lysine as a model biomolecule to establish the best conditions for reductive amination. Finally, two peptides, P₂ and P₅ (epitopes of the SARS-CoV-2 spike protein), were bound on the surface of the LDH to produce two subunit vaccine candidates, reaching peptide concentrations of 125 and 270 µg/mL, respectively. The particles were characterized using DLS, TEM, XRD, TGA, DSC, and FTIR. The cytotoxicity studies revealed that the conjugate with P₂ was non-toxic up to 250 µg/mL, while the immunogenicity studies showed that this conjugate induced similar IgG titers to those reached when aluminum hydroxide was used as an adjuvant. Full article