Here we present an economical ambient pressure drying method of preparing monolithic silica aerogels from methyltrimethoxysilane precursor while using sodium bicarbonate solution as the exchanging solvent. We prepared silica aerogels with a density and a specific surface area of 0.053 g·cm⁻³ and 423 m²·g⁻¹, respectively. The average pore diameter of silica aerogels is 23 nm as the pore specific volume is 1.11 cm³·g⁻¹. Further, the contact angle between water droplet and the surface of silica aerogels in specific condition can be as high as 166°, which indicates a super-hydrophobic surface of aerogels.

中文翻译：

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碳酸氢钠溶液对在常压下干燥的甲基三甲氧基硅烷衍生的二氧化硅气凝胶的影响

在这里，我们提出了一种经济的环境压力干燥方法，该方法由碳酸三钠溶液作为交换溶剂，由甲基三甲氧基硅烷前体制备整体硅胶气凝胶。我们制备的二氧化硅气凝胶的密度和比表面积分别为0.053 g·cm ^-3和423 m ² ·g ^-1。二氧化硅气凝胶的平均细孔直径为1.11cm ³ ·g ^-1时，平均细孔径为23nm 。此外，在特定条件下水滴与二氧化硅气凝胶表面之间的接触角可以高达166°，这表明气凝胶表面具有超疏水性。