EAGER: Forced Assembly of Nanocomposite Structures using Polymer Crystallization

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

This EArly-concept Grant for Exploratory Research (EAGER) award provides funding to evaluate the feasibility of assembling nanoparticles in semi-crystalline polymer matrices using polymer crystallization and crystal morphology as the driving force and template for assembly, respectively. Specifically, the experimental activities will focus on three key issues related to this assembly process using a series of gold nanoparticle/polyethylene oxide nanocomposites. First, structural and morphological characterization activities will be used to identify where nanoparticles locate in the polymer crystal structure. The specific locations preferred by the nanoparticles in this hierarchical structure will have impacts on the material's potential applications. Second, the materials used in the model nanocomposite system will allow the effects of component interactions on the assembly process to be robustly examined which will govern material design guidelines. And third, calorimetric studies using a wide range of rates will be used to determine if the structures resulting from this assembly method are kinetically-trapped or are in a quasi-equilibrium state. Understanding the structure's thermodynamic nature will have implications on determining processing strategies that favor nanoparticle assembly. If successful, the envisioned morphologies resulting from this research have functional and structural applications with direct application to bulk heterojunction organic photovoltaics (OPVs) since the performance of OPV devices is often tied to the degree of crystallinity and length scale of phase segregation achieved. Ultimately, advances in the areas of OPV efficiency and stability will lead to wide-spread replacement of the more expensive silicon-based photovoltaic devices, making solar energy a more affordable energy source and reducing dependence on fossil fuels. Beyond OPVs, hierarchical nanocomposite morphologies have applications as biomedical implants with improved mechanical stability during degradation as well as structural materials with cellular morphologies. Finally, the research results will provide valuable, new insight to understanding the fundamental crystallization behavior of semi-crystalline nanocomposites which is clearly needed to disruptively advance this area.