Molecular Simulations of PIM-1-like Polymers of Intrinsic Microporosity

Polymers of intrinsic microporosity, or PIMs, are characterized by rigid and nonlinear or nonplanar backbones that inhibit space efficient packing, thus creating microporosity. PIM-1 has been well studied by both simulations and experiments and is compared in this work to two different PIM-1-like polymers, PIM-1c and PIM-1n. A detailed method for the generation of representative structures, including charge assignment from ab initio calculations, is presented along with simulated characterization of the pore size distributions, surface areas, structure factors, and methane adsorption isotherms. Simulated scattering for PIM-1c and PIM-1n show similar characteristic peaks as PIM-1, suggesting similar conformations. Adsorption isotherms of methane in PIM-1, PIM-1c, and PIM-1n were also predicted and compared to experimental data for PIM-1.