Mass transfer of weak acid in nanometer-sized pores of octadecylsilyl-silica gel.
The sorption of bromophenol blue or anthracene-9-carboxylic acid as a weak acid into single octadecylsilyl (ODS)-silica gel microparticles in a solution was analyzed by microcapillary injection-manipulation and absorption microspectroscopy. The distribution ratio and the sorption rate were highly dependent on the pH of the solution. These results are discussed in terms of the acid dissociation/association, distribution between the ODS and solution phases, and intraparticle diffusion of the weak acid in the nanometer-sized pores of the ODS-silica gel.
Kakizaki
Hiroshi
H
Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki 305-8571, Japan.
Aonuma
Chiaki
C
Nakatani
Kiyoharu
K