Transparent super-hydrophobic monolithic silica aerogels are prepared by the cost-effective ambient pressure drying. The drying of aerogel is performed at various temperatures ranging from 25 to 200°C. Oxidation states of different silica aerogels are investigated by XPS which shows the presence of both SiO and SiO 2 phases. Thermal stability of hydrophobic aerogel is found as ~320°C investigated by TGA and DSC. The chemical bonds (i.e., –CH 3 ) responsible for the hydrophobic (WCA > 170°) nature of synthesized silica aerogels are identified by FTIR. Further, out-gassing properties of the silica aerogels have been investigated and they are found in limit for the space application. The highest hardness and Young’s modulus are measured by the nanoindentation technique for the aerogel dried at 120°C which has higher density, while density decreases for the aerogel dried at 200°C and the corresponding nanomechanical properties are found to be lowest as expected.

中文翻译：

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通过常压干燥开发的空间应用超疏水透明二氧化硅气凝胶的结构、排气和纳米力学性能

通过具有成本效益的常压干燥制备透明的超疏水整体二氧化硅气凝胶。气凝胶的干燥在 25 至 200°C 的各种温度下进行。通过 XPS 研究了不同二氧化硅气凝胶的氧化状态，这表明存在 SiO 和 SiO 2 相。通过 TGA 和 DSC 研究发现疏水性气凝胶的热稳定性约为 320°C。FTIR 确定了合成二氧化硅气凝胶疏水（WCA > 170°）性质的化学键（即–CH 3 ）。此外，已经研究了二氧化硅气凝胶的除气特性，并且发现它们在空间应用方面受到限制。最高硬度和杨氏模量是通过纳米压痕技术测量的，气凝胶在 120°C 干燥后具有更高的密度，