(289i) Predicting the Equilibrium Structure of Polymer Nanocomposites

Authors: 
Koski, J., University of Pennsylvania
Riggleman, R. A., University of Pennsylvania

Polymer field theory has been transformative in the study of inhomogeneous polymer systems, such as polymer blends and block copolymers.  The power of field theory resides in the ability to efficiently model polymer systems on the order from a few nanometers to several hundred nanometers while working within a framework that is easily related to experiments. Numerous polymer applications are often enhanced with the incorporation of nanoparticles.  The inclusion of both polymers and nanoparticles, namely, polymer nanocomposites (PNCS), has been shown to improve material properties such as electrical, optical, and mechanical properties, which are not achievable with polymers or nanoparticles alone.  Unfortunately, we only really understand the thermodynamics of polymer nanocomposites in a few select cases, and there is a significant need for methods that are capable of efficiently predicting the equilibrium structure of polymer nanocomposites.

In recent years, we have extended the framework of polymer field theory to capture particle correlations and allow for the study of nanoparticles in phase-separated polymer matrices.  We believe that this extension of the polymer field theory framework allows for efficient study of bulk polymer nanocomposite systems where other methods may be limited by mean-field approximations, large computational expense, or the ability to study systems which macro- or microphase separate.

In this talk, I provide some key details of this framework and illustrate its potential by demonstrating its applicability to bulk polymer nanocomposite systems where we can relax the mean-field approximation, study systems with several hundred nanoparticles, and systems that can macro- or microphase separate (e.g. polymer blends or block copolymers).  Additionally, I show how our method is easily extended to particles of an abstract shape and grafted nanoparticles with simple (homopolymer grafting) or complex grafted architectures (diblock, mixed, and Janus grafting).  Finally, I will show results where our field theoretic simulations have guided recent experiments by our collaborators.