Abstract Highly flexible and hydrophobic silica aerogels were synthesized using methyltriethoxysilane and polydimethysiloxane as precursors via two-step acid–base catalyzed sol-gel and supercritical drying. The effects of different precursor and catalyst content on mechanical properties, thermal properties, and contact angles of aerogels were investigated. The aerogels prepared here can be compressed to as high as ~50% of original length and recovered back to their original length. The aerogels showed the hydrophobicity with a water contact angle of 145.6° and low thermal conductivity of 0.0338 W/(mK). Thermal gravimetric analysis shows that the aerogels were thermally stable up to 350 °C. The mechanical and thermal mechanisms of the silica aerogels were also studied. The prepared silica aerogels that were highly flexible, hydrophobic, and lightweight can be applied in thermal insulation of irregular parts, such as pipelines and outdoor attire that are exposed to moist circumstances as well.

中文翻译：

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溶胶-凝胶法制备具有高柔韧性和疏水性的二氧化硅气凝胶

摘要 以甲基三乙氧基硅烷和聚二甲基硅氧烷为前驱体，通过两步酸碱催化溶胶-凝胶和超临界干燥合成了高柔性和疏水性二氧化硅气凝胶。研究了不同前体和催化剂含量对气凝胶力学性能、热性能和接触角的影响。这里制备的气凝胶可以压缩到原始长度的 50% 左右，然后恢复到原始长度。气凝胶显示出疏水性，水接触角为 145.6°，导热系数低，为 0.0338 W/(mK)。热重分析表明，气凝胶在高达 350 °C 的温度下是热稳定的。还研究了二氧化硅气凝胶的机械和热机制。制备的二氧化硅气凝胶具有高柔韧性、疏水性、