CAREER: Reinforced Biopolymers for Nanocomposite Construction and Materials Science and Engineering Curriculum Development

University Of Delaware, Newark DE

Investigators

Abstract

In this proposed Career award research effort, biopolymers, specifically polypeptides or biodegradable polyesters, will be used as the matrix materials for nanocomposite (NC) construction. The intellectual merit of the proposed work is that both significant fundamental and technological research accomplishments in the area of polymer nanocomposite materials are possible by using biopolymers as matrix materials. Fundamental: A) One can rigorously explore the effect of polymer conformation on nanocomposite formation through secondary structure transitions available in polypeptides (e.g. random coil to rigid-rod a helix). B) One can controllably observe the effects of nanoscopic filler addition on the semi-crystalline phase behavior of polymer matrix material, effects that will significantly affect the ultimate NC properties. Therefore, both conformation effects on NC formation and reinforcement phase effects on polymer crystallization will be directly probed. Technological: the use of biopolymers as the matrix material offers the intriguing possibility of introducing inherent biological properties (e.g. biodegradability, antimicrobial activity) into the NC material for biomedical or environmentally benign uses. These materials could range from possible commodity (antimicrobial packaging) to specialty/biomedical uses (tough, biocompatible implant materials). The intellectual merit extends to the chosen filler for nanocomposite construction in that traditional and exploratory reinforcement materials also provide both fundamental and technological research goals. Fundamental: the use of both 2-dimensional platelet vs. 1-dimensional fibrillar fillers will provide a direct comparison of the effectiveness of the two geometries as adequate NC reinforcement material. While significant work has been performed on 2-d inorganic fillers providing a wealth of literature results with which to compare these biopolymer-based composite results, more recently investigations into the efficacy of carbon nanotubes in polymer matrix reinforcement have also been performed. While the platelet filler to be studied herein will be inorganic clay materials, both hydrophilic and hydrophobically modified, the fibrillar reinforcement will be accomplished by self-assembled b-sheet peptide fibrils, a nanostructure traditionally familiar only to the biological science community. Technological: Peptide fibril reinforcement will provide the opportunity to produce stiff, tough, semicrystalline nanocomposites that are potentially 100% biocompatible and biodegradable due to the inherent peptide chemistry of the reinforcement phase. The broader impacts of the proposed work are due to the interdisciplinary nature of the proposed research project, the proposed scientific outreach, and the integration of research topics into new courses proposed to be developed by the PI. One of the most important, broader impacts of this proposed work is the interdisciplinary research education of the graduate students who will perform the research. A modern MSEG department must reflect current interdisciplinary research paradigms and topical material in the classroom environment in order to properly educate and train students interested in materials. Towards this end, a new, advanced polymer science and engineering course will be developed that integrates the physical property assessment results from the Pochan lab NC research effort with classroom lecture material inspired by courses recently developed and taught by the PI. This new course would be part of an ongoing, aggressive effort by the entire faculty in MSE at the University of Delaware (UD) to design and implement a totally new, 21st century materials curriculum.