METHOD FOR MEASURING CONCENTRATION OF SILANOL GROUP

摘要

PROBLEM TO BE SOLVED: To provide a method for readily measuring silanol groups of low concentration in silica particles, suitably usable in controlling the physical properties of the silica particles. SOLUTION: To measure the concentration (mmol/g) of silanol groups in silica particles through absorptiometry using near infrared rays as light sources, the silica particles are dispersed in an organic solvent and the resulting dispersion obtained is used as a sample to measure absorbancy in an absorption band of 4200 to 4800 cm-1 or 6800 to 7400 cm-1 by transmission method. The absorbancy measured is compared with the absorbancy of an organic solvent solution of organosilanol of known silanol group concentration and is thereby converted into silanol group concentration.