“…The characteristics of surfactant absorption are complex and multi-faceted (Theng et al, 1967;Lagaly and Weiss, 1971;Pan et al, 1997;Chen et al, 1998). The orientation of the adsorbed alkylammonium is a function of the layer composition and charge density of the clay (Lagaly and Weiss, 1971;Ertem et al, 2010), and these aspects tend to differ amongst bentonitic montmorillonites (Jonas and Roberson, 1966).…”