Surface chemistry of K-montmorillonite: ionic strength, temperature dependence and dissolution kinetics.

Abstract

The surface chemistry of K-montmorillonite was investigated by potentiometric titrations conducted at 25, 50 and 70 degrees C and at ionic strengths of 0.001, 0.01 and 0.1 M KNO(3). Proton adsorption decreases with electrolyte concentration at all pHs. The pH of zero net proton charge (PZNPC) decreases from 8.1 to 7.6 when the ionic strength increases from 0.001 to 0.1 M. Temperature has a very small effect on surface charge. A constant capacitance model that accounts for protonation/deprotonation of aluminol and silanol edge sites and basal plane H(+)/K(+) exchange is used to fit the experimental data. H(+) and OH(-) adsorption to specific surface sites appear to account for the pH-dependence of the K-montmorillonite dissolution.

DOI: 10.1016/j.jcis.2009.01.059

Cite this paper

@article{Rozaln2009SurfaceCO, title={Surface chemistry of K-montmorillonite: ionic strength, temperature dependence and dissolution kinetics.}, author={Marisa Rozal{\'e}n and Patrick V Brady and Francisco J Huertas}, journal={Journal of colloid and interface science}, year={2009}, volume={333 2}, pages={474-84} }