本文研究了酸催化条件下（pH≈3），TEOS（正硅酸乙酯）水解制备二氧化硅干凝胶过程中，不同胶凝速度对所获得的干凝胶表面分形特性的影响，并分析了煅烧处理的影响．实验以盐酸为催化剂，丙酮为溶剂．结果表明，胶凝速度对未经煅烧的二氧化硅干凝胶表面分形维数几乎没有影响，但较慢的胶凝速度下制备的二氧化硅干凝胶在600℃煅烧后，其表面分形维数有较大的降低．改变煅烧温度的实验表明，在600℃以上继续提高煅烧温度，一般二氧化硅干凝胶的表面分形维数可维持到800℃以上不出现显著下降．
This paper investigated the effect of gelation speed on the surface fractal dimensions of silica xerogels derived from TEOS (actone
as solvent, catalyzed by HCl, pH≈3), and analyzed the influence caused by calcination. The results show that different gelation speeds hardly
affect the surface fractal dimensions of the xerogels without calcination, but the surface fractal dimensions of xerogel acquired with slower gelation
speed will decrease more after calcinated at 600℃. Generally, the surface fractal dimensions of calcinated silica xerogel can remaine almost
unchanged over 800℃.
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