Doctor of Philosophy (PhD)
Molecularly imprinted polymers (MIPs) are finding important applications in the field of separation science, catalysis, sensor, and immunoassays. To optimize the performance of the MIPs, it is essential to understand the underlying mechanism of the process. This research focuses on understanding binding site formation and performance, and improvement of the MIPs. Chapter 1 introduces the concept of the MIPs, and binding isotherm and affinity distribution of heterogeneous binding sites in the MIPs. Chapter 2 describes fundamental studies conducted to understand the binding site formation of the MIPs. The number of binding sites (N) and the number average association constant (Kn) were calculated for each different percent template imprinted polymer using the continuous affinity distribution analysis (AD). The trends of N and Kn for the polymer provided evidence that the final binding site of a molecularly imprinted polymer does not necessarily reflect the solution phase structure, thus the pre-polymer complex in solution is not "locked-in" as previously believed. Chapter 3 describes studies done to understand solvent effects on the binding performance of the imprinted polymers. Strong correlation between solvent-polymer interactions and enantioselectivity, and the visual inspection of the Benesi-Hildebrand plots of the enantiomers provided evidences that the solvent effects in MIPs are due to structural changes in the binding site, such as geometrical distortion of the binding cavity and proximity of the functional groups. Chapter 4 describes a new approach developed to incorporate multiple functional groups in the binding site of MIPs without unproductive interactions between functional monomers (“orthogonal approach”) utilizing a polymerizable crown ether derivative. This "orthogonal" functional group system is shown to act cooperatively in the MIPs to bind a template with higher selectivity than any of the individual functional monomers alone. Chapter 5 describes the value of Kn and heterogeneity index (n) obtained from the AD analysis on a combinatorial library mixture in evaluating binding properties of its components. The trends of Kn and n observed for different mixtures provided means to compare average value and distribution of the association constants of the corresponding components.
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Kim, Hyunjung, "New insights into the binding site formation and the performance of molecularly imprinted polymers" (2004). LSU Doctoral Dissertations. 451.
David A. Spivak