Search Results (363)

Paper’s inherent hydrophilicity and porosity cause inadequate barrier properties, failing under high humidity/temperature. This study successfully developed a hydrophobic nanocoating agent (xLNPs-OTS) through silanization modification using D276 (lignin nanoparticles with a diameter of 276 nm) as the substrate and OTS (octadecyltrichlorosilane) as the functionalizing agent. By applying the coating to paper surfaces followed by a hot-pressing process, the paper achieved comprehensive performance enhancements, including superior water, oil, and vapor barrier properties, thermal stability, mechanical strength, frictional resistance, and self-cleaning capabilities. The Cobb 60 value of LOTSC3.5T120t30 (the coating made from the OTS silanized lignin with the coating amount of 3.5 g/m² and a hot-pressing at 120 °C for 30 min) coated paper is as low as 3.75 g/m², and can withstand hot water at 100 °C for 60 min. The Cobb 60 value of the LOTSC20T120t30 (the coating made from the OTS silanized lignin with the coating amount of 20 g/m² and a hot-pressing at 120 °C for 30 min) coated paper is reduced to 0.9 g/m², the Kit grade is 6, and all coated papers are endowed with self-cleaning features. This study advances lignin’s high-value utilization, driving sustainable packaging and supporting eco-friendly paper material development. Full article

The applications of magnetic particles in anti-counterfeiting and anti-absorbing coatings and other functional materials are becoming increasingly widespread. However, due to their high density, the magnetic particles rapidly settle in organic resin media, significantly affecting the quality of the related products. Thereby, reducing the density of the particles is essential. To achieve this goal, high-density magnetic particles were coated onto the surface of hollow silica using anion–cation composite technology. Further, the silane coupling agent N-[3-(trimethoxysilyl)propyl]ethylenediamine was bonded to the surface of magnetic particles to form an amino-covered interfacial layer with a pH value of 9.28, while acrylic acid was polymerized and coated onto the surface of hollow silica to form a carboxyl-covered interfacial layer with a pH value of 4.65. Subsequently, the two materials were compounded to obtain a low-density composite magnetic material. The morphologies and structural compositions of the magnetic composite materials were studied by FTIR, SEM, SEM-EDS, XRD, and other methods. The packing densities of the magnetic composite materials were compared using the particle packing method, thereby solving the problem of magnetic particles settling in the resin solution. Full article

To investigate the impermeability of foam concrete in various challenging environments, this study evaluates its water resistance by measuring the water contact angle and water absorption. Polyurethane (PU) was used to fabricate polyurethane foam concrete (PFC), enabling a monolithic hydrophobic modification to improve the permeation performance of foam concrete. The study also examines the effects of carbonation and freeze–thaw environments on the permeation resistance of PFC. Graphene oxide (GO), KH-550, and a composite hydrophobic coating (G/S) consisting of GO and KH-550 were employed to enhance the permeation resistance of PFC through surface hydrophobic modification. The functionality of the G/S composite hydrophobic coating was confirmed using energy dispersive X-ray spectrometry (EDS) and Fourier transform infrared spectroscopy (FTIR). The results showed the following: (1) The water contact angle of PFC increased by 20.2° compared to that of ordinary foam concrete, indicating that PU-based hydrophobic modification can significantly improve its impermeability. (2) After carbonation, a micro–nano composite structure resembling the surface of a lotus leaf developed on the surface of PFC, further enhancing its impermeability. However, freeze–thaw cycles led to the formation and widening of microcracks in the PFC, which compromised its hydrophobic properties. (3) Surface hydrophobic modifications using GO, KH-550, and the G/S composite coating improved the anti-permeability properties of PFC, with the G/S composite showing the most significant enhancement. (4) GO filled the tiny voids and pores on the surface of the PFC, thereby improving its anti-permeability properties. KH-550 replaced water on the surface of PFC and encapsulated surface particles, orienting its R-groups outward to enhance hydrophobicity. The G/S composite emulsion coating formed a hydrophobic silane layer inside the concrete, which enhanced water resistance by blocking water penetration, reducing microscopic pores in the hydrophobic layer, and improving impermeability characteristics. Full article

In the present study, we synthesized fluorocarbon-coated cobalt ferrite (CoFe₂O₄) magnetic nanoparticles using alkoxysilanes such as trimethoxy(3,3,3-trifluoropropyl)silane (TFPTMS), trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane (NFHTMS), and triethoxy(1H,1H,2H,2H-perfluorodecyl)silane (PFDTES). The synthesized nanoparticles were characterized by various techniques, including X-ray diffractometry (XRD), transmission electron microscopy (TEM/HRTEM/EDXS), Fourier transform infrared spectroscopy (FTIR), specific surface area measurements (BET), and magnetometry (VSM). To understand their surface characteristics, contact angle (CA) measurements were carried out, providing valuable insights into their hydrophobic properties. Among the samples of CoFe₂O₄ coated with fluoroalkoxysilanes, those with PFDTES surface coating had the highest water contact angle of 159.2°, indicating their superhydrophobic character. The potential of the prepared fluoroalkoxysilane-coated CoFe₂O₄ nanoparticles for the removal of waste low-SAPS synthetic engine oil from a model aqueous solution was evaluated based on three key parameters: adsorption efficiency (%), adsorption capacity (mg/g), and desorption efficiency (%). All synthesized CoFe₂O₄ samples coated with fluoroalkoxysilane showed high oil adsorption efficiency, ranging from 87% to 98%. The average oil adsorption capacity for the samples was as follows: F₃-SiO₂@CoFe₂O₄ (3.1 g of oil/g of adsorbent) > F₉-SiO₂@CoFe₂O₄ (2.7 g of oil/g of adsorbent) > F₁₇-SiO₂@CoFe₂O₄ (1.5 g of oil/g of adsorbent) as a result of increasing oleophobicity with increasing fluorocarbon chain length. The desorption results, which showed 77–97% oil recovery, highlighted the possibility of reusing the adsorbents in multiple adsorption/desorption cycles. Full article

Polyamide 6,6 (PA6,6) fabrics are widely used in textiles due to their high mechanical strength and chemical stability. However, their inherent flammability and melting behavior under fire pose significant safety challenges. In this study, a dual-layer flame-retardant system was developed by integrating atomic layer deposition (ALD) of ZnO with a phosphorus–silane-based flame retardant (DOPO-ETES). ALD allowed precise control of ZnO layer thickness (50, 84, and 199 nm), ensuring uniform coating. Thermal analysis (TGA) and microscale combustion calorimetry (MCC) revealed that ZnO altered the degradation pathway of PA6,6 through catalytic effects, promoting char formation and reducing heat release. The combination of ZnO and DOPO-ETES resulted in further reductions in heat release rates. However, direct flame tests showed that self-extinguishing behavior was not achieved, emphasizing the limitations related to the melting of PA6,6. TG-IR and cone calorimetry confirmed that ZnO coatings suppressed the release of smoke-related volatiles and incomplete combustion products. These findings highlight the potential of combining metal-based catalytic flame retardants like ZnO with phosphorus-based coatings to improve flame retardancy while addressing the specific challenges of polyamide textiles. This approach may also be adapted to other fabric types and integrated with additional flame retardants, broadening its relevance for textile applications. Full article

To address the challenges of cotton cellulose materials being susceptible to environmental humidity and pollutant erosion, a strategy for constructing superhydrophobic functional coatings with biomimetic micro–nano composite structures was proposed. Through surface silanization modification, diatomite (DEM) and Fe₃O₄ nanoparticles were functionalized with octyltriethoxysilane (OTS) to prepare superhydrophobic diatomite flakes (ODEM) and OFe₃O₄ nanoparticles. Following the multi-scale composite principle, ODEM and OFe₃O₄ nanoparticles were blended and crosslinked via the hydroxyl-initiated ring-opening polymerization of epoxy resin (EP), resulting in an EP/ODEM@OFe₃O₄ composite coating with hierarchical roughness. Microstructural characterization revealed that the micrometer-scale porous structure of ODEM and the nanoscale protrusions of OFe₃O₄ form a hierarchical micro–nano topography. The special topography combined with the low surface energy property leads to a contact angle of 158°. Additionally, the narrow bandgap semiconductor characteristic of OFe₃O₄ induces the localized surface plasmon resonance effect. This enables the coating to attain 80% light absorption across the 350–2500 nm spectrum, and rapidly heat to 45.8 °C within 60 s under 0.5 sun, thereby demonstrating excellent deicing performance. This work provides a theoretical foundation for developing environmentally tolerant superhydrophobic photothermal coatings, which exhibit significant application potential in the field of anti-icing and anti-fouling. Full article

Low-surface-energy and wettability-based antifouling coatings have garnered increasing attention in marine applications owing to their environmentally friendly characteristics. However, their limited functionality often results in suboptimal long-term antifouling performance, particularly under dynamic marine conditions. To address these limitations, a polydimethylsiloxane (PDMS)-based slippery (PSL) coating was fabricated on TC4 titanium alloy by integrating surface silanization via (3-Aminopropyl)triethoxysilane (APTES), antimicrobial Ag-TiO₂ nanoparticles, laser-induced hierarchical microtextures, and silicone oil infusion. The resulting PSL coating exhibited excellent oil retention and stable interfacial slipperiness even after thermal aging. Compared with bare TC4, low-surface-energy Ag-containing coatings, Ag-containing superhydrophobic coatings, and conventional slippery liquid-infused porous surfaces (SLIPS), the PSL coating demonstrated markedly superior resistance to protein adsorption, bacterial attachment, and diatom settlement, indicating an enhanced synergistic antifouling effect. Furthermore, it significantly reduced the diatom concentration in the surrounding medium without complete eradication, underscoring its eco-friendly and non-disruptive antifouling mechanism. This study offers a scalable, durable, and environmentally benign antifouling strategy for marine surface protection. Full article

Highly heat-resistant and low-dielectric materials are crucial for achieving high-frequency communication, high-density integration, and high-temperature stability in modern electronics. In this work, surface modification of hollow silica microspheres (HGMs) using a silane coupling agent ((3-aminopropyl)triethoxysilane, KH550) yielded KHGM particles with a coating content of approximately 9.3 wt%, which were subsequently incorporated into high-performance polyarylene ether nitrile (PEN) polymers to fabricate composite films. The modified nanoparticles demonstrated significantly enhanced compatibility with the polymer matrix, while their hollow structure effectively reduced the dielectric constant of the composite film. When loaded with 50 wt% KHGM particles, the PEN-based composite film exhibited an elevated glass transition temperature of 198 °C and achieved a dielectric constant as low as 2.32 at 1 MHz frequency, coupled with dielectric loss below 0.016; compared with pure PEN, the dielectric constant of PEN/KHGM-50% decreased by 26.47%. Additionally, the composite demonstrated excellent water repellency. These advancements provide high-performance material support for applications in electronic communications, aerospace, and related fields. Full article

The inherent flammability and hydrophilicity of nylon/cotton (NC) blend fabrics limit their practical applications. Traditional hydrophobic treatments often involve fluorinated compounds or nanomaterials, which raise environmental concerns and exhibit poor durability. To address these issues, this study developed a sustainable multifunctional finishing strategy. Initially, the nylon/cotton blended fabric was pretreated with 3-glycidyloxypropyltrimethoxy silane (GPTMS). An intumescent flame retardant coating based on bio-derived phytic acid (PA) and polyethyleneimine (PEI) was constructed on NC fabrics via a layer-by-layer (LBL) self-assembly process. Subsequently, polydimethylsiloxane (PDMS) was grafted to reduce surface energy, imparting synergistic flame retardancy and superhydrophobicity. The treated fabric (C-3) showed excellent flame retardant and self-extinguishing behavior, with no afterflame or afterglow during vertical burning and a char length of only 35 mm. Thermogravimetric analysis revealed a residual char rate of 43.9%, far exceeding that of untreated fabric (8.6%). After PDMS modification, the fabric reached a water contact angle of 157.8°, indicating superior superhydrophobic and self-cleaning properties. Durability tests showed that the fabric maintained its flame retardancy (no afterflame or afterglow) and superhydrophobicity (WCA > 150°) after 360 cm of abrasion and five laundering cycles. This fluorine-free, nanoparticle-free, and environmentally friendly approach offers a promising route for developing multifunctional NC fabrics for applications in firefighting clothing and self-cleaning textiles. Full article

Steel fibers are widely used in cementitious composite materials to enhance their mechanical properties, such as tensile strength and toughness. However, the effectiveness of these fibers largely depends on their surface characteristics and bonding with the cement matrix. This study investigated the effects of various treatment processes on the microhardness and mechanical strength of steel fibers in cementitious composite materials. These methods include acetone and acid washing, silane coupling agent treatment, and nanosilica coating. Fibers washed with acetone exhibited a cleaner surface, primarily due to the removal of impurities. Acid treatment resulted in a notably roughened surface, which significantly enhanced mechanical interlocking with the surrounding matrix. Silane treatment led to an uneven surface with distinct vertical textures, potentially improving adhesion properties. Meanwhile, fibers treated with nanosilica displayed a coating of nanoparticles adhering to the surface, which may further influence the fiber–matrix interaction. The results of the mechanical properties tests indicated that nanosilica coating was the most effective in improving both the flexural and compressive strengths, especially in the early strengths in the cement matrix. Full article

The widespread phase-out of long-chain per- and poly-fluoroalkyl substances (PFASs) has created an urgent need for durable, fluorine-free water-repellent finishes that match the performance of legacy chemistries while minimising environmental impact. Here, the performance of an eco-friendly hybrid organic–inorganic treatment obtained by the in situ hydrolysis–condensation of triethoxy(octyl)silane (OS) in an amino-terminated polydimethylsiloxane (APT-PDMS) aqueous dispersion was investigated. The sol was applied to plain-weave cotton and polyester by a pad-dry-cure process and benchmarked against a commercial fluorinated finish. Morphology and chemistry were characterised by SEM–EDS, ATR-FTIR, and Raman spectroscopy; wettability was assessed by static contact angle, ISO 4920 spray ratings, and AATCC 193 water/alcohol repellence; and durability, handle, and breathability were evaluated through repeated laundering, bending stiffness, and water-vapour transmission rate measurements. The silica/PDMS coating formed a uniform, strongly adherent nanostructured layer conferring static contact angles of 130° on cotton and 145° on polyester. After five ISO 105-C10 wash cycles, the treated fabrics still displayed a spray rating of 5/5 and AATCC 193 grade 7, outperforming or equalling the fluorinated control, while causing ≤5% loss of water-vapour permeability and only a marginal increase in bending stiffness. These results demonstrate that the proposed one-step, water-borne sol–gel process affords a sustainable, industrially scalable route to high-performance, durable, water-repellent finishes for both natural and synthetic textiles, offering a viable alternative to PFAS-based chemistry for outdoor apparel and technical applications. Full article

Mesoporous silica nanoparticles (MSNs) functionalized with silane quaternary ammonium compounds (SiQACs) were synthesized and utilized as carriers for thymus essential oil (TO), a green bio-antifouling agent. The synthesis of MSNs functionalized with SiQACs was carried out in a single step, with clear advantages in terms of simplicity of the process, high yield (94%) and saving of reagents and solvents for the MSN purification. After loading with TO, this innovative dual-action antifouling system was able to integrate the intrinsic biocidal properties of SiQACs with the release of TO from MSN pores, resulting in an engineered material with prolonged efficacy. The antifouling compounds incorporated into the nanoparticles accounted for 42% of the total weight. The biocidal performance was evaluated by monitoring the growth inhibition of Chlorella sorokiniana, a microalga commonly associated with stone biodeterioration. Additionally, these nanoparticles were embedded in a commercial silane-based protective coating and applied to tuff stone samples to assess their ability to mitigate biofilm formation over extended periods. Results demonstrated the system’s high potential for durable protection against microbial colonization and biofilm growth on stone surfaces. Full article

Many kinds of silicones are a wide family of hybrid inorganic–organic polymers which have valuable physical and chemical properties and find plenty of practical applications, not only industrial, but also numerous medical and pharmaceutical ones, mainly due to their good thermal and chemical stability, hydrophobicity, low surface tension, biocompatibility, and bio-durability. The important biomedical applications of silicones include drains, shunts, and catheters, used for medical treatment and short-term implants; inserts and implants to replace various body parts; treatment, assembly, and coating of various medical devices; breast and aesthetic implants; specialty contact lenses; and components of cosmetics, drugs, and drug delivery systems. The most important achievements concerning the biomedical and pharmaceutical applications of silicones, their copolymers and blends, and also silanes and low-molecular-weight siloxanes have been summarized and updated. The main physiological properties of organosilicon compounds and silicones, and the methods of antimicrobial protection of silicone implants, have also been described and discussed. The toxicity of silicones, the negative effects of breast implants, and the environmental effects of silicone-containing personal care and cosmetic products have been reported and analyzed. Important examples of the 3D printing of silicone elastomers for biomedical applications have been presented as well. Full article

This study aims to develop a robust and reproducible method for fabricating efficient ultrathin antifouling coatings on gold surfaces by leveraging hydroxylation-based surface modifications. An ultrathin antifouling coating of a monoethylene glycol silane derivative, known to reduce fouling by at least 90% on flat hydroxylated surfaces, was successfully replicated on flat gold (reducing fouling by ~75%) by hydroxylating its surface with β-mercaptoethanol. This tandem coating contains the monoethylene glycol silane layer on top of the β-mercaptoethanol on the gold. Characterization was performed using contact angle goniometry, atomic force microscopy, x-ray photoelectron spectroscopy, and antifouling measurements. The results from these techniques, consistent with the literature, confirmed the successful and reproducible application of the tandem coating. Through heterogeneities, including defects and incomplete coverage, the AFM data revealed distinct visible layers of the tandem coating. The direct application of monoethylene glycol silane onto gold resulted in superior antifouling performance (88% reduction), demonstrating that direct silylation exploits pre-existing oxygen-containing species on the gold surface for a more effective antifouling layer. These findings offer a scalable approach for engineering antifouling coatings on gold substrates, with potential applications in biosensing and implantable device antifouling technologies. Full article

Nanomaterials (NMs) have gained tremendous attention in various applications in the modern era. The most significant challenge associated with NMs is their strong propensity to aggregate. The chemical surface modification of NMs has garnered notable attention in managing NM dispersion and aggregation. Among the modification approaches, the silane modification of NMs has generated great interest among researchers as a versatile approach to tailoring the surface characteristics of NMs. This review comprehensively examined the recent advancements in silane modification techniques with a focus on triboelectric nanogenerator (TENG) applications. It provides an overview of silane chemistry and its interaction with diverse NMs, elucidating the underlying mechanisms governing the successful surface functionalization process. This review emphasized the silane modification, such as improved mechanical properties of composites, enhanced electrical and thermal conductivity, functional coatings, water treatment, textile industries, catalysis, membrane applications, and biomedical applications, of various NMs. In particular, the role of silane-modified NMs in advancing energy harvesting technologies was highlighted, showcasing their potential to enhance the performance and stability of next-generation devices. Full article