Search Results (8)

Dimethyl methylphosphonate (DMMP) and modified nano-silica were utilised to enhance the mechanical properties, thermal stability, and flame retardancy of waterborne polyurethane (WPU). Nano-silica modified with the silane coupling agent γ-aminopropyltriethoxysilane (KH550) exhibited excellent dispersibility and stability. Compared with pure WPU, the limiting oxygen index (LOI) of P/Si-WPU increased from 18.1% to 28.3%, and its UL-94 rating reached V-0, with a significant improvement in elongation at break. Furthermore, the peak heat release rate of P/Si-WPU decreased by 29.1%, while the total heat release was reduced by 6.8% in comparison to pure WPU. The synergistic flame-retardant mechanism of phosphorus and silicon was investigated through an analysis of the char residue of WPU and its composites. This study provides a potential approach for the development of WPU with superior flame retardancy and enhanced mechanical properties. Full article

In this study, the impact of the addition of high-aspect-ratio nano-ettringite to photocurable epoxy acrylate resin was explored. The nano-ettringite samples were modified using γ-Aminopropyltriethoxysilane (KH-550) and γ-methacryloxypropyl trimethoxy silane (KH-570). Then, 3 wt% or 6 wt% KH-550-modified, KH-570-modified, and unmodified nano-ettringite samples were dispersed into resin via ultrasonic treatment in conjunction with mechanical stirring. The grafting effects of nano-ettringite onto KH-550 or KH-570 were analyzed through scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric (TG) analysis. The results demonstrate that KH-550 and KH-570 have been successfully grafted onto the surface of nano-ettringite. In addition, this study also focuses on the variations of composite materials in the viscosity, shrinkage, tensile strength, and elongation at break. The results indicate that increased dosages of unmodified, KH-550-modified, and KH-570-modified nano-ettringite led to increased viscosity of the composite while reducing shrinkage. At the same dosage, the photocurable resin containing KH-570-modified nano-ettringite demonstrated a lower shrinkage and a higher tensile strength. From the analysis of tensile fracture surfaces, it was observed that compared to the KH-550 modified and unmodified variants, the KH-570 modified nano-ettringite exhibits superior dispersibility in photocurable epoxy acrylate resin. Notably, when the amount of KH-570-modified nano-ettringite was 3 wt%, the highest tensile strength of the composite was 64.61 MPa, representing a 72.57% increase compared to the blank sample. Furthermore, the incorporation of KH-570-modified nano-ettringite as a filler provides a new perspective for improving the performance of photocurable epoxy acrylate resin composites. Full article

Nano-hydroxyapatite (HAp) is an ideal material in the field of biomedicine due to its good biocompatibility and bioactivity. However, a significant drawback of pure HAp materials is their inferior mechanical properties. Therefore, in this rigorous investigation, the optimal calcium-to-phosphorus ratio for the synthesis of HAp was meticulously delineated, followed by its nuanced modification using KH550 (γ-aminopropyltriethoxysilane). This was further amalgamated with polycaprolactone (PCL) with the aim of providing a superior material alternative within the domain of bone scaffold materials. The post-modified HAp demonstrated enhanced interfacial compatibility with PCL, bestowing the composite with superior mechanical characteristics, notably a peak bending strength of 6.38 ± 0.037 MPa and a tensile strength of 3.71 ± 0.040 MPa. Scanning electron microscope (SEM) imagery revealed an intriguing characteristic of the composite: an initial ascension in porosity upon HAp integration, subsequently followed by a decline. Beyond this, the composite not only exhibited stellar auto-degradation prowess but also realized a sustained release cycle of 24 h, markedly optimizing drug utility efficiency. A kinetic model for drug dispensation was developed, positing an adherence to a pseudo-second-order kinetic principle. In tandem, through the formulation of an intra-particle diffusion model, the diffusion mechanisms pre- and post-modification were deeply probed. Cytotoxicity assays underscored the composite’s exemplary biocompatibility. Such findings accentuate the vast potential of the modified HAp–PCL composite in bone tissue engineering, heralding a novel and efficacious avenue for impending bone defect amelioration. Full article

The hydrophobic nature of inorganic zeolite particles plays a crucial role in the efficacy of mixed matrix membranes (MMMs) for the separation of trichloroethylene (TCE) through pervaporation. This study presents a novel approach to further augment the hydrophobicity of ZSM-5. The ZSM-5 zeolite molecular sieve was subjected to modification using three different silane coupling agents, namely, n-octyltriethoxysilane (OTES), γ-methacryloxypropyltrimethoxysilane (KH-570), and γ-aminopropyltriethoxysilane (KH-550). The water contact angles of the resulting OTES@ZSM-5, KH-570@ZSM-5, and KH-550@ZSM-5 particles exhibited significant increases from 97.2° to 112.8°, 109.1°, and 102.7°, respectively, thereby indicating a notable enhancement in hydrophobicity. Subsequently, mixed matrix membranes (MMMs) were fabricated by incorporating the aforementioned silane-modified ZSM-5 particles into polydimethylsiloxane (PDMS), leading to a considerable improvement in the adsorption selectivity of these membranes towards trichloroethylene (TCE). The findings indicate that the PDMS membrane with a 20 wt.% OTES@ZSM-5 particle loading exhibits superior pervaporation performance. When subjected to a temperature of 30 °C, flow rate of 100 mL/min, and vacuum of 30 Kpa, the separation factor and total flux of a 3 × 10⁻⁷ wt.% TCE solution reach 328 and 155 gm⁻²·h⁻¹, respectively. In comparison to the unmodified ZSM-5/PDMS membrane, the separation factor demonstrates a 41% increase, while the TCE flux experiences a 6% increase. Consequently, this approach effectively enhances the pervaporation separation capabilities of the PDMS membrane for TCE. Full article

Epoxy resin is extensively used in gas insulated switches as a renewable energy coating due to its exceptional insulation, mechanical characteristics, and environmental friendliness. The higher resistivity of the epoxy resin causes numerous surface charges to accumulate on the surface of the epoxy resin as a result of carrier injection due to the high DC electric field, which may cause insulation failure of the power transmission system. In this study, various concentrations of epoxy resins blended with nano-alumina (nano-Al₂O₃) at 0 wt%, 1 wt%, 3 wt%, and 5 wt% were created. Afterwards, the epoxy resin and Al₂O₃ nanocomposites were fluorinated by utilizing a combination of F₂ and N₂ with a ratio of 20% F₂ at 0.05 MPa while maintaining the temperature at 40 °C. In order to improve dispersion, nano-Al₂O₃ was treated with a silane coupling agent called γ-aminopropyltriethoxysilane (KH550). Additionally, infrared spectroscopy based on the Fourier transform was used to investigate the structure of chemical bonds. Furthermore, the changes in the molecular chains were verified by the FTIR spectra. The DC breakdown strength of epoxy resin\Al₂O₃ nano-composites showed that breakdown strength significantly improved after gas-phase fluorination. Moreover, 1 wt% nano-Al₂O₃ showed a higher breakdown strength. The fluorinated layer had a charge-suppressing effect, reducing the charge injected into the polymer matrix of the epoxy-resin matrix and increasing its DC breakdown capability. Thermally stimulated current (TSC) measurements indicate that epoxy resin’s trap energy and trap density are altered by nano-Al₂O₃ incorporation and fluorination treatment (gas-phase). It was also observed that introducing nano-Al₂O₃ at a lower concentration (e.g., 1 wt%) can hinder the growth of space charge in the polymer matrix of the epoxy resin, thus enhancing the deep traps’ energy. Furthermore, a fluorination layer containing a strong polarization of C-F bonding would seize the charge injection from electrodes, thus decreasing the conductivity and suppressing the charge injection. Full article

Fine art coating is usually created by the combination of metal filler and water-based coatings, decorated to the surface of wood structures, furniture, and crafts. However, the durability of the fine art coating is limited by its weak mechanical qualities. In contrast, the metal filler’s dispersion and the coating’s mechanical properties can be significantly improved by the coupling agent molecule’s ability to bind the resin matrix with the metal filler. In this study, a brass powder-water-based acrylic coating was prepared, and three different silane coupling agents, 3-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560), and γ-methacryloxypropyltrimethoxysilane (KH570), were used to modify the brass powder filler in orthogonal tests. The artistic effect and optical properties of the modified art coating induced by different proportions of brass powder, silane coupling agents, and pH were compared. The result demonstrated that the amount of brass powder and the kind of coupling agent used had a substantial impact on the coating’s optical characteristics. Our results also determined how three different coupling agents affected the water-based coating with varying brass powder contents. The findings indicated that 6% KH570 concentration and pH 5.0 were the ideal conditions for brass powder modification. Better overall performance of the art coating applied to the surface of the Basswood substrates was provided by adding 10% of the modified brass powder into the finish. It had a gloss of 20.0 GU, a color difference of 3.12, a color main wavelength of 590 nm, a hardness of HB, an impact resistance of 4 kg·cm, an adhesion of grade 1, and better liquid resistance and aging resistance. This technical foundation for the creation of wood art coatings promotes the application of art coatings on wood. Full article

A superhydrophobic material was prepared by a simple and easily accessed sol-gel method using epoxy resin (E-51) and γ-aminopropyltriethoxysilane (KH-550) as the precursors, aqueous ammonia (NH₄OH) as the catalyst and hydrogenated silicone oil (PMHS) as the hydrophobic modifier, and then pelleting the final product. The morphologies, surface chemical properties and thermal stability of the superhydrophobic bulk materials were characterized by scanning electron microscopy, Fourier infrared spectrometry and thermal analyzer. The hydrophobic properties and repairability of the as-prepared materials were also studied. The results showed that the prepared epoxy resin-hydrogenated silicone oil bulk materials were composed of tightly bound nanoparticles with a size of 50–100 nm in diameter. The material showed excellent superhydrophobic properties with a surface contact angle of 152°. The material also had good thermal resistance with a heat-resistant temperature of 300 °C and showed good repairability. The epoxy resin-hydrogenated silicone oil bulk superhydrophobic material exhibited excellent performance and showed wide application prospects. Full article

Organically-modified magadiite (MAG–CTAB–KH550) was synthesized via ion-exchange method and condensation reaction in the presence of pure magadiite (MAG), cetyltrimethylammonium bromide (CTAB) and γ-aminopropyltriethoxysilane (KH550) in aqueous solution in this research. This new adsorbent material was studied using scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and N₂ adsorption/desorption isotherms process. It was found that the MAG–CTAB–KH550 has high Brunaur-Emmet-Teller (BET) specific surface area and mesoporous pore size distribution which enhanced its ability to remove phenol in aqueous solution; and, the value of pH has a relatively large impact on the adsorption behavior of the sorbent. Finally, the adsorptive behavior of the mesoporous material on phenol was followed pseudo-second-order kinetic adsorption model. In contrast, the adsorption equilibrium isotherm was better performed Langmuir isotherm model than the Freundlich isotherm model; in addition, the results also showed that the MAG–CTAB–KH550 had a better adsorption capacity and removal efficiency than MAG. Full article