Date of Award

Fall 12-15-2017

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Ishrat Khan, Ph.D.

Second Advisor

Cass Parker, Ph.D.

Third Advisor

Myron Williams, Ph.D.

Abstract

A novel chiral helical imprinted polymer (MIP) has been prepared by bulk copolymerization of 3-methyl-4-vinylpyridine and a crosslinker using chiral S-mandelic acid as template. The resulting MIPs after removing the template show optical activity that is derived from the presence of chiral helical structures of poly(3-methyl-4-vinylpyridine) (P3M4VP) embedded within the MIP matrix. The basic functional monomer 3-methyl-4-vinylpyridine (3M4VP) was utilized with the acidic template to ensure good interaction between the template and the polymer. Divinylbenzene (DVB) and ethyleneglycoldimethacrylate (EGDMA) with widely varying degree of rigidity, flexibility, and polarity were selected as crosslinking agents. Using two different crosslinkers, it was possible to optimize the MIP for maximum specificity and selectivity. Spectroscopic methods such as FT-IR and 1H NMR were used to investigate the interaction between template and functional monomer. Scanning electron microscopy and nitrogen sorption analysis showed significant difference of the surface morphological characteristics between imprinted and non-imprinted polymers.

Thermogravimetric analysis (TGA) was carried out to investigate thermal stability of MIPs and NIPs. The binding studies and the selectivity of the polymers were analyzed using UV-visible spectroscopy. The chiral secondary or higher structural ordering within the MIPs was examined using circular dichroism (CD) spectrometry. The polymer preparations were evaluated and compared with non-imprinted polymers for their ability to bind the template which is a measure of the specificity of the imprinted system. The nature and degree of crosslinking and other parameters like concentration of the template solution, solvent, and time which influences the binding of these imprinted polymers towards the print molecule were also investigated to optimize the imprinted system. The ability of the S-enantiomer imprinted polymer to bind the R-enantiomer was investigated. The separation and selectivity factors have been quantified. The present study develops a successful strategy for preparing chiral MIPs, which are expected to find vital applications in chiral separation, and enantioselective release of chiral drugs.

Share

COinS