摘要
用巨正则 Ｍｏｎｔｅ Ｃａｒｌｏ（ＧＣＭＣ）方法模拟了超临界甲烷在层柱纳米材料中的吸附．模拟中，层柱纳米材料采用了柱子均匀分布在层板间的模型，非极性分子甲烷采用Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ分子模型，层板墙采用Ｓｔｅｅｌｅ的１０－４－３模型，流体分子与柱子的相互作用采用点－点（ｓｉｔｅ ｔｏ ｓｉｔｅ）的方法计算．得到了甲烷的随着压力先增大后减小的超额吸附等温线．在 Ｔ＝ ２０７．３ Ｋ时，１．０２、１．７０和 ２．３８ ｎｍ孔宽对应的最适操作压力（即对应于最大吸附量时的操作压力）分别为２．４、３．１和３．７ ＭＰａ．然而，在 Ｔ＝２３７．０ Ｋ时，１．０２、１．７０和２．３８ ｎｍ孔宽对应的最适操作压力分别为２．９、３．６和４．９ ＭＰａ，分别比 Ｔ＝２０７．３ Ｋ时相同孔宽下对应的最适操作压力至少高 ０．５ＭＰａ．模拟结果表明，ＧＣＭＣ方法是研究材料吸附性能的一种强有力的工具．
A grand canonical Monte Carlo(GCMC) method is carried out to investigate adsorption of supercritical methane in layered pillared nano-material. In the simulation, layered pillared nano-material is modeled by the approach of Yi et al([6, 7]) with a uniform distribution of pillars. Steele's 10-4-3 potential is used for representing the interaction between a Lennard-Jones(LJ) methane molecule and a layered wall in the GCMC simulation. The site-site interaction is also used for calculating the interaction between methane of U fluid and pillars. The classical excess adsorption isotherms of methane with three different pore widths, are obtained at two supercritical temperatures T = 207. 3 and 237. 0 K. The optimum adsorption pressures, corresponding to the greatest excess adsorption, are 2. 4, 3. 1 and 3. 7 MPa in the pore widths 1. 02, 1. 70 and 2. 38 nm at temperature 207. 3 K, respectively. It can be found that the optimum adsorption pressures increase with the increase of temperature under otherwise identical conditions, which are 2. 9, 3. 6 and 4. 9 MPa, respectively, corresponding to pore widths of 1. 02, 1. 70 and 2. 38 urn at T = 237. 0 K. Simulation indicates that the GCMC method is a useful tool for providing the optimum adsorption pressure of supercritical methane in layered pillared nano-materials.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2001年第10期940-943,共4页
Acta Physico-Chimica Sinica
基金
国家重点基础研究发展规划基金(G2000048010)
国家自然科学基金(2977604)
国家高性能计算基金(99118)
