(273f) Correlating the Structure and Properties of Imprinted Gels with Reaction Parameters

Macromolecular recognition is reported to improve template binding properties in weakly and highly crosslinked polymer networks. Binding properties of imprinted gels are said to be influenced by the structural homogeneity of the polymer matrix as well as the quality and quantity of non-covalent complexation sites formed by the imprinting process. In our previous work, we have demonstrated an improvement in binding properties of the imprinted gels due to the non-covalent chemistries introduced by the imprinting process. With this work we will demonstrate the potential for using reaction analysis as a tool for improving the structural homogeneity of imprinted polymer matrices by correlating the changes in the imprinting and reaction parameters with the observed changes in the mechanical and binding properties of the gels.

Weakly crosslinked (5% crosslinking) poly(methacrylic acid-co-ethylene glycol dimethacrylate) gels were used to perform the experiments. The various gels studied differed in terms of either the imprinting parameter (template/functional monomer ratio) or the reaction parameters ((iniferter/conventional photoinitiator ratio or solvent content in reaction mixture). The structural analysis of the imprinted poly(MAA-co-EGDMA) gels included swelling experiments in multiple solvents. In addition, samples of each gel were analyzed with a RSA III Dynamic Mechanical Analyzer. Equilibrium binding experiments were carried out to calculate the template affinity and binding capacity. Corresponding poly(MAA) homopolymers were also created and analyzed using gel permeation chromatography (GPC).

The structural analysis of the polymer gels yielded their average mesh size while the binding analysis carried out using the freundlich isotherm yielded their imprinting efficiencies. The GPC results for the corresponding homopolymers indicate that template-monomer complexes formed affect polymer structure formation even with homopolymer systems. The results demonstrate that reaction analysis can be very useful for achieving improved structural homogeneity of template binding sites within the polymer matrix which in turn result in improved binding and delayed transport. This work is leading to a greater understanding of the structural configuration of imprinted polymer matrices and how to manipulate properties of these polymers using reaction analysis for emerging applications in the fields of drug delivery and biosensor substrates.