(4r) Computational Studies of Polymeric Systems

Computer experiments have become routine because of the availability of faster and larger computer clusters. Together with the development of parallel algorithms and the availability of accelerators such as GPU’s, we are poised to handle larger simulations that approach sizes comparable to real-life experiments or perform orders of magnitude more smaller experiments. To illustrate I am presenting the results of my latest works. (1) I performed coarse-grained molecular dynamics of the thermal annealing of the active layer of an organic photovoltaic device. The simulations of the OPV were performed on the Titan supercomputer for up to 400 ns and the simulation sizes are comparable to the thickness of the active layer of a bulk heterojunction device (~100 nm). (2) I performed coarse-grained molecular dynamics simulations of polymer networks with varying stiffness of the networks’ polymer chain to explain the highly nonlinear stress–strain behavior manifested in these networks that stiffen with increasing deformation.  Although the sizes of the second set of simulations are small, we performed many samples that covered the whole range of polymer chain flexibility from Gaussian coils to rigid rods. In both cases, we have compared the results with theories and experiments in order to provide insights and get a better understanding of the physics of these processes. In the future, I hope to perform simulations that would tackle areas in polymer physics that are not yet fully understood such as charged polymers, liquid crystalline polymers and polymer crystallization.  In these future works, I will actively search for areas of collaboration with theorists and experimentalists in the hope of contributing in presenting a more complete picture of what is happening in these polymeric systems.