Identifier

etd-07132007-014052

Degree

Doctor of Philosophy (PhD)

Department

Chemistry

Document Type

Dissertation

Abstract

Studies of grafting polymer on surfaces with chemical bonds started in the 1970’s, but few projects have focused on grafting polypeptide on spherical particles. In this research, polypeptides poly(å-carbobenzyloxy-L-lysine) (PCBL) or poly(ã-benzyl-L-glutamate) (PBLG) were grafted on silica sphere surfaces by using the “grafting from” method. The polypeptide-grafted silica spheres are called SiPCPs. The growth of polypeptide chains as a function of monomer amount and reaction time was explored. The properties of a mixture of PBLG rod-like polymer and PBLG SiPCPs were investigated. At high concentrations of these two components, the phase behavior was studied. At low concentrations of PBLG, the fluorescein isothiocyanate (FITC) labeled PBLG SiPCPs were used as probes to measure the probe diffusion through the PBLG matrix in pyridine. Because of the depletion-attraction effect, the mixture becomes very viscous even at low concentrations; consequently the diffusion of probe is very slow. A holographic fluorescence photobleaching recovery (FPR) instrument, which creates the grating from the interference of two crossed beams, was developed to satisfy such a specific condition. The polypeptides were grafted on silica spheres with a cobalt core inside, and Co-SiPCPs were formed. Preliminary results demonstrate that these particles can respond to an external magnetic field and the solvent can affect the magnetic behaviors of these particles.

Date

2007

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Palu S. Russo

Included in

Chemistry Commons

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