Polarized infrared attenuated total reflection for the in situ determination of the orientation of surfactant adsorbed at the solid/solution interface

Research was conducted to examine are determine the average orientation of the methylene tail of cetyltrimethylammonium bromide (CTAB) using polarized infrared attenuated reflection. Calculations were made of the methylene absorbance bands of CTAB adsorbing on silica in the S and P polarized states. Results indicate that surfactant desorption occurs in localized areas and that the residual surfactant is present in isolated clusters of highly ordered molecules that take a considerable time to relax their orientation.