Wang Weilin, Tong Zongwei, Li Ran, Su Dong, Ji Huiming
Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China.
Materials (Basel). 2021 Apr 19;14(8):2046. doi: 10.3390/ma14082046.
In order to improve the mechanical properties of SiO aerogels, PHMS/VTES-SiO composite aerogels (P/V-SiO) were prepared. Using vinyltriethoxysilane (VTES) as a coupling agent, the PHMS/VTES complex was prepared by conducting an addition reaction with polyhydromethylsiloxane (PHMS) and VTES and then reacting it with inorganic silica sol to prepare the organic-inorganic composite aerogels. The PHMS/VTES complex forms a coating structure on the aerogel particles, enhancing the network structure of the composite aerogels. The composite aerogels can maintain the high specific surface area and excellent thermal insulation properties, and they have better mechanical properties. We studied the reaction mechanism during preparation and discussed the effects of the organic components on the structure and properties of the composite aerogels. The composite aerogels we prepared have a thermal conductivity of 0.03773 W·m·K at room temperature and a compressive strength of 1.87 MPa. The compressive strength is several times greater than that of inorganic SiO aerogels. The organic-inorganic composite aerogels have excellent comprehensive properties, which helps to expand the application fields of silicon-based aerogels.
为了提高SiO气凝胶的力学性能，制备了PHMS/VTES-SiO复合气凝胶（P/V-SiO）。以乙烯基三乙氧基硅烷（VTES）为偶联剂，通过聚甲基氢硅氧烷（PHMS）与VTES进行加成反应制备PHMS/VTES络合物，然后使其与无机硅溶胶反应制备有机-无机复合气凝胶。PHMS/VTES络合物在气凝胶颗粒上形成涂层结构，增强了复合气凝胶的网络结构。复合气凝胶能够保持高比表面积和优异的隔热性能，并且具有更好的力学性能。我们研究了制备过程中的反应机理，并讨论了有机组分对复合气凝胶结构和性能的影响。我们制备的复合气凝胶在室温下的热导率为0.03773W·m·K，抗压强度为1.87MPa。抗压强度比无机SiO气凝胶大几倍。有机-无机复合气凝胶具有优异的综合性能，这有助于拓展硅基气凝胶的应用领域。
