Chen Dangjia, Gao Hongyi, Liu Panpan, Huang Pei, Huang Xiubing
Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory of Function Materials for Molecule & Structure Construction, School of Materials Science and Engineering, University of Science and Technology Beijing No. 30, Xueyuan Road, Haidian District Beijing 100083 PR China
RSC Adv. 2019 Mar 15;9(15):8664-8671. doi: 10.1039/c8ra08646j. eCollection 2019 Mar 12.
Robust low-cost silica based aerogels can be obtained by choosing appropriate silane precursors and chemical conditions. In this paper, we synthesized two kinds of bridged siloxane precursors, bridged silsesquioxane (BSQ) from (3-aminopropyl)-triethoxysilane (APTES) and -phthalaldehyde (MPA), and bridged methylsiloxane (BMSQ) from (3-aminopropyl)-diethoxymethylsilane (APDEMS) and -phthalaldehyde (MPA) to prepare robust aerogels. Methanol and ethanol were used individually as solvents in the experiment and all the products were dried directly at ambient pressure without any solvent exchange process. All the products show low densities (about 0.15 g cm) and large porosities (larger than 80%). The influence of the precursor and solvent was investigated. The BSQ aerogels have larger specific surface areas, smaller pore sizes and more stable mechanical performances. Aerogels prepared using methanol as the solvent gel faster and have larger pore sizes. The solvent has greater impacts on the BSQ aerogels, the BSQ aerogels prepared using ethanol as the solvent can withstand 60% deformation in repeated compression tests, exhibiting good mechanical performance.
通过选择合适的硅烷前驱体和化学条件，可以获得坚固且低成本的二氧化硅基气凝胶。在本文中，我们合成了两种桥连硅氧烷前驱体，由（3-氨丙基）-三乙氧基硅烷（APTES）和间苯二甲醛（MPA）合成桥连倍半硅氧烷（BSQ），以及由（3-氨丙基）-二乙氧基甲基硅烷（APDEMS）和间苯二甲醛（MPA）合成桥连甲基硅氧烷（BMSQ），以制备坚固的气凝胶。实验中分别使用甲醇和乙醇作为溶剂，所有产物均在常压下直接干燥，无需任何溶剂交换过程。所有产物均显示出低密度（约0.15 g/cm）和大孔隙率（大于80%）。研究了前驱体和溶剂的影响。BSQ气凝胶具有更大的比表面积、更小的孔径和更稳定的机械性能。以甲醇为溶剂制备的气凝胶凝胶化速度更快且孔径更大。溶剂对BSQ气凝胶的影响更大，以乙醇为溶剂制备的BSQ气凝胶在反复压缩测试中可承受60%的变形，表现出良好的机械性能。
