Choi Haryeong, Parale Vinayak G, Lee Kyu-Yeon, Nah Ha-Yoon, Driss Zied, Driss Dorra, Bouabidi Abdallah, Euchy Souhir, Park Hyung-Ho
Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Korea.
Laboratory of Electro-Mechanic Systems (LASEM), National School of Engineers of SENIS), University of Sfax, 3.5 Soukra, 3038 Sfax, Tunisia.
J Nanosci Nanotechnol. 2019 Mar 1;19(3):1376-1381. doi: 10.1166/jnn.2019.16257.
Silica aerogels possess low thermal conductivity but have a brittle nature, while their polymers tend to exhibit enhanced mechanical properties. In this study, we introduce a new approach to overcoming this brittle property of silica aerogels. Polypropylene/silica aerogel composites were prepared by thermally induced phase separation followed by a supercritical CO₂ drying method. Silica aerogel was formed onto a polypropylene scaffold using a two-step sol-gel process with methyltrimethoxysilane as the silica precursor. Enhancement of the mechanical properties of the polypropylene/silica aerogel composite compared with a pristine methyltrimethoxysilane-based silica aerogel was observed. The effects of the latter on the microstructure and physical properties of the polypropylene/silica aerogel (hereafter referred to as the polymer matrix aerogel) composite were investigated. Compared with the polypropylene monolith, the polymer matrix aerogel composite demonstrated enhanced surface-chemical and microporous-structural properties such as higher hydrophobicity (135°), pore volume (0.18 cm³/g), average pore diameter (12.55 nm), and specific surface area (57.2 m²/g). This novel approach of incorporating methyltrimethoxysilane-based silica aerogel onto polypropylene when synthesizing the polymer matrix aerogel composite shows great potential as a durable superhydrophobic and corrosion resistant thermal insulating material.
二氧化硅气凝胶具有低导热性，但质地易碎，而其聚合物往往表现出增强的机械性能。在本研究中，我们引入了一种新方法来克服二氧化硅气凝胶的这种易碎特性。通过热致相分离然后采用超临界二氧化碳干燥法制备了聚丙烯/二氧化硅气凝胶复合材料。以甲基三甲氧基硅烷作为二氧化硅前驱体，采用两步溶胶 - 凝胶法在聚丙烯支架上形成二氧化硅气凝胶。观察到与原始的基于甲基三甲氧基硅烷的二氧化硅气凝胶相比，聚丙烯/二氧化硅气凝胶复合材料的机械性能有所增强。研究了后者对聚丙烯/二氧化硅气凝胶（以下简称聚合物基体气凝胶）复合材料的微观结构和物理性能的影响。与聚丙烯整体材料相比，聚合物基体气凝胶复合材料表现出增强的表面化学和微孔结构性能，如更高的疏水性（135°）、孔体积（0.18 cm³/g）、平均孔径（12.55 nm）和比表面积（57.2 m²/g）。在合成聚合物基体气凝胶复合材料时，将基于甲基三甲氧基硅烷的二氧化硅气凝胶掺入聚丙烯的这种新方法，作为一种耐用的超疏水和耐腐蚀隔热材料具有巨大潜力。
