Abstract:
Covalent organic framework (COF) is a sort of porous materials with big BET and low density, which has broad potential applications in capturing of greenhouse gases. In this paper, computer simulation is adopted to investigate the adsorption and separation of CO2-CH4 in COFs such as COF-102. Four published charge models of CO2: (1) C(0.70 e) with O(-0.35 e),and the bond length of C=O is 1.16×10-10m; (2) C(0.576 e) with O(-0.288 e),and the bond length of C=O is 1.18×10-10m; (3) C(0.544 e) with O(-0.272 e),and the bond length of C=O is 1.18×10-10m; (4) C(0.664 5 e) with O(-0.332 25 e),and the bond length of C=O is 1.16×10-10m, UFF and Dreiding of COF are selected during the computer simulation. The adsorption isotherms and the selectivity of CO2-CH4 mixture in COFs were simulated by using the above charge models and force fields. Through the comparison between the simulation results and the published experiments, the simulation based on UFF and the second charge model is closest to the results of experiments.