Influence of polymer morphology on the adsorption behaviors of molecularly imprinted polymer-methacrylic acid functionalized beta-cyclodextrin

摘要

The influence of molecularly imprinted polymer-methacrylic acid functionalized -cyclodextrin (MIP(MAA--CD)) morphology on the adsorption behavior studies towards benzylparaben (BzP) was explored. The effects of time, concentration, and temperature towards BzP uptake were extensively evaluated. The adsorption performance of MIP(MAA--CD) was compared with that on the molecularly imprinted polymer-methacrylic acid (MIP(MAA)) synthesized without -CD. The MIP(MAA--CD) was synthesized to obtain a spherical and spongy-porous texture with a broad pore size distribution. The MIP(MAA--CD) showed fast kinetic and the intra-particle diffusion model demonstrated a three step (surface and pore) adsorption process. The Koble-Corrigan isotherm was the most suitable model for data fitting, which indicated that MIP(MAA--CD) had homogeneous and heterogeneous surfaces. This finding clearly demonstrated that the large uptake and strong affinity of MIP(MAA--CD) did not only probably result from the monomer-template interactions, but also due to the morphological MIP(MAA--CD) structure. In contrary to MIP(MAA--CD), MIP(MAA) synthesized with uniform morphology and narrow pore size distribution had lower adsorption capacities and its kinetic data fitted the pseudo-second order diffusion model, indicating a two-step (surface only) adsorption process. The MIP(MAA) adsorption process followed the Langmuir isotherm model referred to solely homogeneous uptake. The calculated thermodynamic parameters showed that the BzP uptake was exothermic, spontaneous, and physisorption process onto MIPs, which supported the results of kinetics and isotherm adsorption data. This study clearly revealed that the presence of -CD improved the morphology of synthesized MIP, and automatically enhanced the adsorption behavior of MIP. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42720.