关键词: 分子筛, 吸附, 蒙特卡罗法, 微观结构

Adsorption isotherm of nitrogen in MCM-41 at temperature T = 77 K was measured by using the ASAP 2010 volumetric adsorption analyzer produced by Micromeritics Instrument Corp.. The BET specific surface was obtained. Based on the BJH analysis method, which is a suitable method for analyzing adsorption of fluid in meso-porous materials, the BJH adsorption cumulative pore volume and average pore diameter were also solved. The grant canonical Monte Carlo (GCMC) simulation was also carried out to investigate the adsorption of nitrogen in MCM-41 at T = 77 K. In our GCMC simulation, the MCM-41 material was modeled as cylindrical pore, and nitrogen was considered as the Lennard-Jones spherical molecule. The Tjatjopoulos-Feke-Mann (TFM) potential was used for representing the interaction between nitrogen molecules and cylindrical pore walls. In the simulation, the diameter size was taken from the result measured. Simulated adsorption isotherm of nitrogen in MCM-41 was obtained, and the micro-structure of the fluid in MCM-41 was also analyzed, which is good guidance to understand the mechanism of adsorption. Note that a set of parameters representing MCM-41 was determined by making the experiment isotherm and simulation isotherm in a good agreement, which is a basis for predicting the adsorption of other adsorbate in MCM-41.

Key words: MOLECULAR SIEVE, ADSORPTION, MONTE CARLO METHOD, MICRO-STRUCTURE