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In this research project, the hexagonal boron nitride@(silver/copper) (h-BN@(Ag/Cu)) hybrids are successfully synthesized through a jointly decorated two-step process in this work. First, the copper nanoparticles (CuNPs) are decorated on h-BN flakes by reducing copper ions (Cu2+). Subsequently, h-BN@(Ag/Cu) hybrids are fabricated via silver nanoparticles (AgNPs) deposition on the surface of hexagonal boron nitride@copper (h-BN@Cu) flakes. The obtained h-BN@(Ag/Cu) hybrids serve as loading fillers to substantially boost the thermal conductivity of poly(dimethylsiloxane) (PDMS). The thermal conductivity of as-prepared h-BN@(Ag/Cu)/PDMS composite reaches 1.5645 W m−1 K−1 at 25 vol% filler loading. Furthermore, the electrical properties of these composites are comprehensively investigated. Additionally, the mechanism of h-BN@(Ag/Cu) hybrids for thermal conductivity improvement are demonstrated utilizing Fogg's model. This work may provide valuable insight and information for the design and construction of high-performance thermally conductive materials in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Polymer composites with electrical insulation and high thermal conductivity are in high demand in the electronics industry. The application potential of electronics material mainly depends on its mechanical properties. In this work, the silver nanoparticles (AgNPs) modified siloxane/graphene nanoplatelet core-shell hybrid (Ag@SiO/GNP) is synthesized through a two-step process. First, hydrolysis-condensation of TEOS and MPS is performed on the surface of pre-treated GNP. Subsequently, AgNPs are decorated on SiO/GNP core-shell hybrids to obtain Ag@SiO/GNP core-shell hybrid. The as-prepared hybrids serve as fillers of epoxy resin (EPR) to prepare Ag@SiO/GNP/EPR composite with high thermal conductivity (1.03W·m−1·K−1, which is 457.2% higher than pure EPR) and good electrical insulation (>1010Ω) at 1 wt% fillers loading. The hydrolysis-condensation of TEOS and saline coupling agent can decline the electrical conductivity of carbon-based materials efficiently, otherwise, the core-shell hybrids can be modified further based on the existing functional groups. The Ag@SiO/GNP/EPR composites exhibit excellent mechanical properties. The mechanism for thermal conductivity improvement of the composites prepared with these core-shell hybrids is demonstrated in detail. [ABSTRACT FROM AUTHOR]

A battery of siloxane (SiO)/multi-walled carbon nanotube (MWCT) core-shell hybrids are successfully fabricated by encapsulating MWCTs with siloxanes via the hydrolysis-condensation reaction. First, MWCT is treated by the surfactant to improve the surface polarity. Then, the hydrolysis-condensation reaction of tetraethoxysilane (TEOS) and different saline coupling agents is performed on the surface of MWCTs to achieve various core-shell hybrids. These hybrids serve as fillers of epoxy resin (EPR) to prepare high-performance thermally conductive, electrically insulating and strength-enhanced composites at low fillers loadings. The SiO/MWCT/EPR composite possesses high thermal conductivity (0.55 W m−1 K−1, which is 196.7% higher than pure EPR) and excellent electrical insulation (>1012 Ω) at 1 wt% filler loading. The thermal conductivity improvement mechanism for these composites containing SiO/MWCT core-shell hybrids is demonstrated in detail. Moreover, the siloxane encapsulation route for MWCTs significantly declines their electrical conductivity, which greatly upgrades the practical value of as-prepared thermal conductivity composites. [Display omitted] • Siloxane/carbon nanotube core-shell hybrid is successfully fabricated via the hydrolysis-condensation reaction. • The EPR composites with SiO/MWCT core-shell hybrid fillers possess high thermal conductivity (0.55 W m−1 K−1). • The EPR/SiO/MWCT composite shows excellent electrical insulation (>1012 Ω) at 1 wt% filler loading. • This research provides a practical avenue for producing conductive and electrically insulating materials. [ABSTRACT FROM AUTHOR]

Anti-corrosion coatings have been widely applied to protect metals against corrosion attacks. To improve the corrosive resistance, it is an effective way to employ porous materials loaded with corrosion inhibitors as fillers of coatings. One of the critical challenges is to advance the inhibitor loading capability of porous fillers. In this study, the mesoporous silica encapsulation is introduced on the ZSM-5 molecular sieves through the hydrolysis-condensation of tetraethyl orthosilicate (TEOS), followed by calcinated for removing the residual templates. The porous SiO 2 @ZSM-5 particles are used as micro-nano containers to load corrosion inhibitor benzotriazole (BTA). The morphologies, structures and BTA releasing behaviors are thoroughly investigated. Subsequently, the as-prepared BTA-SiO 2 @ZSM-5 particles serve as fillers for waterborne epoxy resin (WER) to fabricate BTA-SiO 2 @ZSM-5/WER composite coatings with long-term anti-corrosion property. The corrosive resistance behavior and mechanism are emphatically tested and analyzed. The results demonstrate that the introduction of mesoporous silica on the ZSM-5 molecular sieves significantly increases the specific surface area and pore volume, which is highly beneficial for improving the BTA loading capability of fillers as well as the anti-corrosion performance of coatings. Moreover, the great dielectric, mechanical and UV light-shielding properties of the composite coatings are confirmed. This study presents an effective and practical route for fabricating long-term anti-corrosive composite coatings. [Display omitted] • The mesoporous silica encapsulation is performed through hydrolysis-condensation to improve BTA loading content. • The BTA-SiO 2 @ZSM-5 particles were used to fabricate BTA-SiO 2 @ZSM-5/WER composite coatings with long-term anti-corrosion. • The great dielectric, mechanical and UV light-shielding properties of the composite coatings are confirmed. [ABSTRACT FROM AUTHOR]

In this study, the easy moisture absorption of molecular sieves was addressed by a two-step surface hydrophobic modification process. First, the hydrolysis-condensation of tetraethoxysilane (TEOS) was performed on the pre-treated ZSM-5 zeolite powders to fabricate silica encapsulated ZSM-5 (SiO 2 @ZSM-5) molecular sieves. Second, hydrogen-containing silicone oil (HCSO) was grafted on the surface of SiO 2 @ZSM-5 molecular sieves to prepare hydrogen-containing silicone oil modified silica@ZSM-5 (HCSO-m-SiO 2 @ZSM-5) nanocomposites. After modification, the BET specific surface area of HCSO-m-SiO 2 @ZSM-5 nanocomposite was reduced from 275 to 69 m2 g−1, the pore volume was decreased from 0.27 to 0.05 cm3 g−1, and the average pore diameter was decreased from 4.6 to 2.6 nm. Then, the HCSO-m-SiO 2 @ZSM-5 nanocomposites were used as fillers to endow epoxy resin (EPR) coatings with hydrophobicity. The water contact angle of as-prepared HCSO-m-SiO 2 @ZSM-5/EPR composite coatings reached up to 148° at 30 wt% filler content. Electrochemical analysis shows that the corrosion potential (E corr) of composite coatings was positively shifted from −1.060 to −0.433 V and the corrosion current (I corr) was reduced from 9.0791 × 10−5 to 2.4433 × 10−6 A/cm2 with the increase of filler content from 0 to 30 wt%, demonstrating their enhanced anti-corrosion property. Furthermore, the dielectric, light-shielding and mechanical properties were investigated. The results indicate that the composite coatings perform multifunctions of good hydrophobicity, dielectric performance, anti-corrosion, light-shielding efficiency and mechanical properties, which may have great potential in electronics applications. [Display omitted] • The hydrogen-containing silicone oil modified silica@ZSM-5nanocomposites were prepared through a two-step process. • The as-prepared HCSO-m-SiO 2 @ZSM-5/EPR composite coatings exhibited hydrophobicity with the water contact angle about 148°. • The composite coatings exhibited good dielectric properties and excellent anti-corrosion property. • The composite coatings presented good light-shielding, flexibility and adhesion performances. [ABSTRACT FROM AUTHOR]