Analysis of the solvent exchange kinetics of acetonitrile on the polymer followed the intraparticle diffusion (IPD) model, and diffusion required longer times to achieve adsorption equilibrium (Figs. and). In addition, the temperature dependence of the solvent exchange revealed that only a few percent of the pores were utilized for the liquid-phase events, even at 313 K (Table ), compared to the total pore volume for micro-and mesopores determined by gas-phase adsorption isotherms using N2 at 77 K. The limited diffusion restricts the maximum sites for Table Thermodynamic parameters for the association/dissociation equilibrium in acetonitrile and PBS (the equilibrium constant K in M -1 , the enthalpy change ΔH in kJ mol -1 , and the entropy change ΔS in J K -1 mol -1 ) at 273 K unless otherwise noted. a These values were derived from the van't Hoff plot between 283 and 313 K as shown in Fig. ; b the value in parenthesis was calculated by computational chemistry using DFT method with PCM(acetonitrile) for implicit solvation.