Doctor of Philosophy (PhD)



Document Type



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.



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Committee Chair

Palu S. Russo



Included in

Chemistry Commons