复合硅源在大理石表面仿生合成二氧化硅保护膜的研究

使用硅酸钠/氟硅酸钠复合硅源,通过仿生合成方法在大理石表面制备得到了一层SiO2为主要成分的保护膜,并对该膜的性能进行了检测评价。运用傅里叶变换红外光谱仪和扫描电子显微镜对膜的结构和形貌进行了表征,探讨了SiO2的成膜机理。结果表明,运用复合硅源可在近中性条件下在大理石表面形成SiO2膜,SiO2颗粒以球形形态沉积在大理石表面,表现出成核、颗粒长大和颗粒堆聚3个阶段。24 h可形成较完整、均匀致密的保护层。该膜不仅具有优良的耐酸、耐候性,还具有良好的透气性能。

复合硅源制备SiO2气凝胶及改性研究

以正硅酸乙酯(Tetraethyl orthosilicate,TEOS)为主要硅源,以三甲基氯硅烷(trimethyl chlorosilane,TMCS)和r-缩水甘油基丙基三甲氧基硅烷(3-Glycidyloxypropyltrimethoxysilane,KH560)作为改性硅源,采用溶胶-凝胶法制备了二氧化硅(SiO2)气凝胶。研究结果表明,改性后SiO2气凝胶的接触角由27°提升至130°;在H2O/TEOS摩尔比为5时,凝胶时间为3min;改性的SiO2气凝胶为多孔结构,密度为0.22g/cm^3,孔隙率为89.9%,比表面积为870.42m^2/g,孔体积为1.38cm^3/g,平均孔径为48.6nm。

不同硅源制备二氧化硅气凝胶研究进展

近年来,二氧化硅气凝胶凭借其优异性能在诸多领域被广泛应用。硅源作为制备SiO_(2)气凝胶最重要的组成部分,对获得结构完整、性能优良的SiO_(2)气凝胶至关重要。本文综述了多种硅源为前驱体的SiO_(2)气凝胶发展历程及制备。硅源种类划分为单一硅源和复合硅源。单一硅源主要有水玻璃、硅溶胶、工农业含硅废料及常见硅醇盐;复合硅源通过引入疏水性和功能性基团来改善结构性能,从而实现其在不同领域的应用。最后对SiO_(2)气凝胶硅源的选择、研究现状及前景进行探讨。

Improvement of Impact Absorbed Energy of CFRPs on Adding the Nanoparticles into Epoxy Resins

The present study investigates the effect of the addition of nanoparticles into epoxy resins as the matrix on the impact absorbed energy of CFRP （carbon fiber reinforced polymer）. Impact absorbed energy is one of the main properties to evaluate the CFRP＇s performance for transportation and aerospace structures. Two types of nanoparticle, namely nanofibers and nano-silica beads, were added into the epoxy resin to improve the impact absorption capacity of the CFRP. Two modified additives and conventional epoxy resins were quantitatively compared. The impact test results showed that impact absorbed energy for nanofibers was higher than nano-silica beads, and nanofibers as the additive promoted about 11% of impact absorbed energy compared with neat epoxy resin.