Application of the Attenuated-Total-Reflection Technique to the Measurement of Silica-Gel Particle Size

Attenuated-total-reflection (ATR) spectra of thinly deposited silica-gel particles measuring several microns in diameter were measured. The band intensity increased monotonously with decreasing the particle diameter as expected from the characteristic of the evanescent wave. The silica-gel particle size was proved to be determined by use of the ATR technique.