Amorphous aluminum hydroxide gels

Abstract The gelation of aluminum hydroxide sols obtained from aluminum-sec-butoxide in acidic media leads, depending on the conditions of preparation, to gels with a structure ranging from crystalline to amorphous to super-amorphous. A model for the structure of “super-amorphous” gels is presented to explain the observations. This model suggests the presence of swollen and folded boehmite planes as essential structural features.