ADSORPTION ENTHALPY AND ADSORPTION-ISOTHERM OF TETRADECYLPYRIDINIUM BROMIDE ON NA-MONTMORILLONITE

The adsorption enthalpy and the adsorption isotherm of tetradecylpyrid inium bromide (TPB) onto a Na-montmorillonite suspension and the dilut ion enthalpy of the TPB solution have been determined at 298.15 K. The dilution process is endothermic and the adsorption process is exother mic, For ion exchange adsorption, the interaction between TP+ and the montmorillonite is much stronger than that between Na+ and the montmor illonite because the cumulative adsorption enthalpy increases dramatic ally with adsorption amount. For molecular adsorption, however, the in teraction between TPB and the clay is much weaker. (C) 1997 Academic P ress