Study of interfacial interaction effects in different systems including polymer nanocomposites and protein adsorption

by Yan Zhang

Institution: University of Cincinnati
Department: Arts and Sciences: Chemistry
Degree: PhD
Year: 2013
Keywords: Chemistry; Graphene; Polymer nanocomposites; Interfacial effect; Protein immobilization
Record ID: 2003289
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384870177


The goal of this project is to investigate the interfacial effect in different systems including polymer nanocomposites and surface immobilized proteins. In order to find out how the interaction between filler and polymer affects the polymer's properties in polymer nanocomposites, different polymers including polydimethylsiloxane and polybutadiene were filled with modified graphene, and mechanical and thermal properties were studied in section one. In addition, interfacial interactions between immobilized protein and modified surface affecting the protein's orientation and protein's activity were studied in section two. Since polymer nanocomposite was discovered by Toyota research group at 1990, it opened a new dimension in the field of polymer and materials science. Polymer nanocomposites consist of a polymer having nanofillers dispersed in the polymer matrix. The use of nanofillers including carbon nanotube and graphene has attracted increasing interest due to their unique properties and potential applications in aerospace, electronic and automotive industries. Polymer nanocomposites show substantial property enhancement at lower filler loading than polymer composites with conventional micro-scale fillers due to strong polymer-filler interaction and better filler dispersion. In protein surface immobilization, the interfacial effect will affect the immobilized protein orientation and morphology. There is an unmet need to develop biocompatible, non-adherent surface coatings for medical devices to combat the complications seen after cardiovascular stenting, a procedure used for hundreds of thousands of Americans each year. Among current post-stenting therapies, including anti-inflammatory drugs and drug eluting stents, long term administration of anti-platelet drugs is required to prevent thrombosis. In order to solve these unmet needs, we synthesized different coatings to covalently couple an enzyme, specifically human soluble calcium-activated nucleotidase (SCAN) protein, seeking to make the metal surfaces more biocompatible. We also investigated the covalently bound enzyme's structure and the characteristics of the adsorbed and covalently bound proteins on the substrate surfaces.