Surface plasmon resonance study of adhesion kinetics of smectites on the Au/water interface: Clay and organo-clay film formation

Surface plasmon resonance was employed for the in-situ investigation of film formation from aqueous dispersions of clay minerals on gold/water interface. High charge (SAz-1) and intermediate charge smectite (STx-1b) were studied for their ability to form stable clay films on gold surfaces and their adhesion kinetics at different concentrations was investigated. Layer charge and charge distribution seems to affect not only the kinetics of film formation but also the overall amount of clay mineral on the gold substrate. Subsequently to stable clay mineral film formation, the in-situ preparation of hybrid organo-clay films with the introduction of alkylammonium chains and their adsorption kinetics was examined. Alkylammonium adsorption via ion exchange in the interlayer of the clay minerals is controlled by the density of the clay mineral film in full accordance with layer charge and charge localization. Hence, a simple self-assembly procedure for the in-situ preparation of hybrid organo-clay films for novel applications is proposed.