Molecular Simulation of I2-H2O Diffusion in Different Pore Structures of Activated Carbon Fiber

Abstract Activated carbon fiber (ACF) is a new, efficient, and multifunctional adsorption material developed in the 1970s. In order to develop an iodine adsorbent of ACF, the diffusion effect of iodine in the pores of ACF was studied. Based on molecular dynamics, and Monte Carlo methods, a pore structure model of ACF was constructed based on carbon nanotubes. The accuracy of the model was verified through diffusion experiments and comparison with simulation results. And then, according to the basic structural unit of the constructed ACF pores, the mean square displacement and radial distribution functions of I2 and H2O under different pore sizes, functional groups and temperatures were studied, and the interaction between I2-H2O was obtained. The results show that for different diffusion components at the same temperature, the diffusion rate shows I2 > CH3I > H2O with the increase of time step. The diffusion rate of I2 is positively correlated with temperature and pore size. For different relative humidity, the diffusion rate is 40% > 80% > 10% with the increase of time steps. This study provides a theoretical basis for achieving the goal of iodine removal of activated carbon fiber.