Adsorption of cetyltrimethyl ammonium bromide surfactant for organophilization of palygorskite clay

Abstract

This work determines the optimal palygorskite (Plg) content (maximum surfactant adsorption point) to achieve organophilization using the cationic surfactant cetyltrimethyl ammonium bromide (CTAB) at various concentrations. Adsorption assays were carried out in a finite bath after varying the content of Plg and CTAB in solution. In those assays, the effects of time, temperature, pH and thermodynamic characteristics were studied. The results were analysed using the Langmuir, Freundlich, Dubinin-Radushkevich and Tempkin adsorption models. The increase in clay content in the dispersion leads to a decrease in adsorption of surfactant on the clay. It was possible to obtain the optimal Plg content to achieve organophilization at various concentrations of CTAB surfactant. The experimental data fitted well to the Freundlich model. The Dubinin-Radushkevich and Tempkin isotherms confirmed the chemical adsorption of CTAB on Plg clay.