Polymer materials are widely applicable to problems energy storage and renewable energy. I developed a method for constructing, equilibrating, running and analyzing polymer simulations. This method has been applied to examine fundamentally important processes, such as energy storage in lithium-ion batteries and gas diffusion through selectively permeable polymer membranes.
I developed a workflow for running polymer molecular dynamics simulations and applied it to a variety of problems, including polymer electrolytes for lithium-ion batteries and semipermeable membranes for CO2 reduction. Work is currently underway on a multiscale description of mixed matrix membranes for air and water treatment.
This workflow consists of several steps. First, the individual polymer chains are constructed in an amorphous builder. Then, the cell is equilibrated using the Desmond simulation package, with a critical Scaled Effective Solvent (SES) equilibration step, which allows for accelerated relaxation of the polymer chains. Afterwards, long timescale molecular dynamics simulations are performed. If needed, the structure can be converted to LAMMPS format for an improved description of electrostatics and surface equilibration.
This method was applied to study several problems including: understanding the diffusion mechanism in polymer electrolytes for lithium-ion batteries and developing an adjustable parameter-free description of gas permeation through polymer membranes.
1. Atomistic description of ionic diffusion in PEO-LiTFSI: effect of temperature, molecular weight, and ionic concentration. In preparation, (2018).
2. Predictive simulation of non-steady-state transport of gases through rubbery polymer membranes. Polymer, (2018).
3. Polarizable charge equilibration model for predicting accurate electrostatic interactions in molecules and solids. The Journal of Chemical Physics, (2017).