Effect of Temperature on the Thermodynamic Properties, Kinetic Performance, and Stability of Polybutadiene-Coated Zirconia

This article describes the results of a study of the effect of temperature on the performance of a reversed-phase material prepared by coating polybutadiene (PBD) on porous zirconia. We examined the effect of temperature on retention, efficiency, and stability of this phase. The thermodynamic properties were evaluated via the separation of alkylbenzenes and a set of tricyclic antidepressant drugs at different temperatures, while the intrinsic kinetic performance of the PBD phase at elevated temperatures was examined by using alkylbenzenes as probe solutes. Moreover, the thermal stability was determined by measuring the drift in k' while continuously pumping a mobile phase at 100 °C. We found that enthalpy changes were between -2 and -4 kcal/mol and that changes in selectivity varied with the type of solute. High temperatures improved the column efficiency by 30%, mainly by accelerating the solute diffusion rate in the stationary phase. Finally, the PBD-coated zirconia phase was very stable at a temperature of 100 °C for at least 7000 column volumes.