直接测定受限在狭窄圆柱硬孔中的方阱流体的固液共存。

Direct determination of fluid-solid coexistence of square-well fluids confined in narrow cylindrical hard pores.

机构信息

Division of Chemical and Biomolecular Engineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore.

出版信息

J Chem Phys. 2010 Jun 14;132(22):224504. doi: 10.1063/1.3429741.

DOI:10.1063/1.3429741

PMID:20550405

Abstract

Fluid-solid phase transition and coexistence of square-well fluids confined in narrow cylindrical hard pores are characterized using molecular simulation methods. The equation of state containing a fluid phase, a solid phase and a fluid-solid coexistence state was separately obtained for different attractive ranges of potential well and pore diameters; lambda=1.2, 1.3, 1.4, and 1.5 for a pore of diameter D=2.2sigma, lambda=1.5 and 1.65 for a pore of diameter D=2.5sigma. For lambda=1.2, 1.3, and 1.4 at pore diameter D=2.2sigma, lambda=1.5 at D=2.5sigma, the fluid-solid phase coexistence densities and pressure are close to the hard sphere fluids at the same temperature, while the pressure decreases significantly for lambda=1.5 at D=2.2sigma and lambda=1.65 at D=2.5sigma, respectively. We also report the structural properties of the systems undergoing a phase transition.

摘要

采用分子模拟方法研究了受限于狭窄圆柱形硬孔中的方阱流体的固-液相转变和共存。对于不同的位阱吸引力范围和孔径，分别得到了包含流体相、固体相和固-液共存相的状态方程；对于孔径为 D=2.2sigma 的孔，λ=1.2、1.3、1.4 和 1.5，对于孔径为 D=2.5sigma 的孔，λ=1.5 和 1.65。对于孔径为 D=2.2sigma 的孔，λ=1.2、1.3 和 1.4，以及孔径为 D=2.5sigma 的孔，λ=1.5，固-液共存密度和压力接近相同温度下的硬球流体，而对于孔径为 D=2.2sigma 的孔，λ=1.5 和孔径为 D=2.5sigma 的孔，λ=1.65，压力显著下降。我们还报告了经历相转变的系统的结构特性。