Jin Huiran, Zhou Xinyu, Xu Tingting, Dai Chenye, Gu Yawei, Yun Shan, Hu Tao, Guan Guofeng, Chen Jing
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 210009, PR China.
School of Chemical Engineering, Huaiyin Institute of Technology, Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, Huai'an 223003, PR China.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11815-11824. doi: 10.1021/acsami.9b20923. Epub 2020 Mar 2.
Clay-based aerogel is a promising material in the field of thermal insulation and flame retardant, but obtaining clay-based aerogel with high fire resistance, low thermal conductivity, hydrophobicity, and mechanical robustness remains a challenge. In this work, palygorskite-based aerogel was successfully fabricated via combining with a very small proportion of alginate to form a distinctive hierarchically meso-microporous structure. By employing ethanol solution (EA) replacement method and freeze-drying process, the resultant aerogel exhibited ultralow density (0.035-0.052 g/cm), practical mechanical strengths (0.7-2.1 MPa), and low thermal conductivity of 0.0332-0.165 W/mK (25-1000 °C). The hydrophobicity of aerogel was achieved by simple chemical vapor deposition of methyltrimethoxysilane (MTMS). The Pal-based aerogel showed good performance in both fire resistance with high limiting oxygen index up to 90%, and heat resistance with tolerance of flame up to 1000 °C for 10 min. This renewable Pal-based aerogel with a 3D framework is a promising material to be applied in fields of construction and aerospace for thermal insulation and high fire resistance.
黏土基气凝胶是隔热和阻燃领域一种很有前景的材料，但制备具有高耐火性、低导热性、疏水性和机械强度的黏土基气凝胶仍然是一个挑战。在这项工作中，通过与极少量藻酸盐结合成功制备了坡缕石基气凝胶，形成了独特的分级介孔-微孔结构。通过采用乙醇溶液（EA）置换法和冷冻干燥工艺，所得气凝胶具有超低密度（0.035-0.052 g/cm）、实用的机械强度（0.7-2.1 MPa）以及在25-1000 °C下0.0332-0.165 W/mK的低导热率。气凝胶的疏水性通过甲基三甲氧基硅烷（MTMS）的简单化学气相沉积实现。基于坡缕石的气凝胶在耐火性方面表现出色，极限氧指数高达90%，在耐热性方面能够耐受高达1000 °C的火焰10分钟。这种具有三维框架的可再生坡缕石基气凝胶是一种很有前景的材料，可应用于建筑和航空航天领域的隔热和高耐火性方面。
