METHOD FOR PREPARING MACROPOROUS SILICA GEL HAVING HIGH-VOLUME OF PORES

摘要

A method of preparing macroporous silica gel with an average diameter of pores ranging from 20 to 40 nm by expanding pores of a narrow-porous silica gel can be characterised in a combined action of some of hydrous, concentrated or saturated solutions of sodium, potassium, lithium or ammonium salts of (in)organic acids in presence of an applied hydroxide cation while preserving a pH value within a range between 8 and 9. The mixture is kept at a boiling temperature for several hours depending on a required pore size. The method is carried out at atmospheric pressure using a simple apparatus. The method, when compared to those known in the art, provides considerable repeatability for preparing silica gels of expanded pores diameters whose volume is decreased only by 5 - 15 percent with respect to the source silica gel.