In this study, we investigate the molecular diffusion of carbon dioxide through hyperbranched polyethyleneimine (HB-PEI) membrane using quantum mechanics and classical molecular dynamics simulation. The effect of various conditions are analyzed. Especially, the effect of water on the dynamics of HB-PEI and the CO2 diffusion is pursued. For this purpose, we design the HB-PEI model according to the experimental observations, and build the 3D model of HB-PEI membrane. The atomic partial charges are assigned using Mulliken population method with B3LYP and 6-31G** and the numbers of primary, secondary, and tertiary amine are determined to have the values from experiments. 3D structures are modeled to have amorphous phase. Using annealing procedure to obtain equilibrium state, the volume compression and expansion with heating and cooling are repeated 5 times, and subsequently the equilibrium MD simulation is performed. CO2 diffusion is evaluated using the mean-square displacement analysis. Then, the correlation of CO2 diffusion with the structure of HB-PEI membrane is elucidated.

Molecular diffusion of carbon dioxide through hyperbranched polyethylenimine

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.