ABSTRACT
The optimal separation of substances by the method can be accomplished by varying either the solvent or the structure of the gel, generally by the manner of drying: air-dried, stored, activated gels, or gels with admixtures show different sorption activities. The preparation of the gels with specific adsorption properties toward a certain substance is accomplished by acidifying water glass and adding an aqueous solution of the particular substance to the mixture. With the printing techniques used so far, the capability of silica gels to print three-dimensional structures appears to be small when compared to stereochemical specificity of biochemical systems. The silica gel system is peculiar insofar as it formulates the information with only a single signal, namely, the silanol group capable of adsorption,* so that the specificity of an information is due solely to the order of this signal. The theoretically derived similarity between biological specificity and specifically adsorbing silica gels can be demonstrated experimentally in some cases.
