Nanoscale Networks for Efficient Energy Conversion

Many energy conversion applications, e.g. PEM fuel cells, bulk heterojunction solar cells, and Dye-Sensitized solar cells, rely on inexpensive, self-assembled, ion conducting networks. These materials are often obtained by the casting of polymer electrolytes via the evaporation of the ambient solvent in a process lasting hours. Modeling a casting process from the atomistic level is prohibative. We have developed a general approach to relax the Canham-Helfrich energy into finite-width interfacial energies which are higher order generalizations of the Cahn-Hilliard energies that possess a much richer structure. The associated gradient flows are able to span the long time scales of the hysteric casting process, and evidence spontaneous network formation, including the pearling instability, in compelling agreement with experimental data. We present an analsyis of these models, and show how they may be validated against coarse-grained MD simulations.