Aqueous Precursors

Abstract

Salts of many cations that dissolve in water are used in the sol-gel process. Depending on the cation, the salts include halides, primarily chlorides. It is also possible to use sulfates, oxysulfates, and nitrates. In addition to salts of mineral acids, the salts of organic acids are suitable as precursors. These include acetates, citrates, lactates, and others. Hydrolysis of the salts leads to various hydroxides, oxyhydroxides, and colloidal sols. In some cases, oxides form directly. The ability to use aqueous precursors is controlled by concentration and pH.