Abstract
Thermodynamic characterization of butyl methacrylate-co-ethylene dimethacrylate neat monolith and zeolitic imidazolate framework-8 incorporated with butyl methacrylate-co-ethylene dimethacrylate composite monolith were studied using inverse gas chromatography at infinite dilution under 1 MPa column pressure and various column temperatures. The free energy of adsorption (Delta G(A)), enthalpy of adsorption (Delta H-A) and entropy of adsorption (Delta S-A) were determined using a series of n-alkanes. The dispersive component of surface energy (gamma(D)(S)) was estimated by Dorris-Gray and Schultz et al. methods. The composite monolith showed a more energetic surface than the neat monolith. The acidic, K-A, and basic, K-D, parameters for both materials were estimated using a group of polar probes. A basic character was concluded with more basic behavior for the neat monolith. Flory-Huggins parameter, chi, was taken as a measure of miscibility between the probes with the low molecular weight and the high molecular weight monolith. Inverse gas chromatography provides a better understanding of the role of incorporated zeolitic imidazolate framework (ZIF-8) into the polymer matrix in its monolithic form. (C) 2016 Elsevier B.V. All rights reserved.