摘要 |
Silica hydrogel is prepared by electrolysis of an aqueous anolyte solution containing an alkali metal silicate and a salt of a non-siliceous anion, such as sodium nitrate or sodium sulfate, in a cell with a cation permselective membrane separating the anolyte and an aqueous catholyte. The electrolysis is effected in the presence of the salt to deposit silica hydrogel on the anode. The hydrogel can be easily recovered from the anode and dried to produce regular and intermediate density silica xerogels having narrow pore size distributions. |