arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0706.0618cond-mat.softcond-mat.stat-mech
收藏

具有相互吸引和排斥作用的流体的相行为

Phase behavior of a fluid with competing attractive and repulsive interactions

Andrew J. Archer, Nigel B. Wilding

摘要:

流体中的粒子间的潜力有一个硬核,是有吸引力的,在中等分离,并在更大的分离排斥已知表现出新的相行为,包括稳定的非均匀相。在这里,我们报告了这样的流体的联合模拟和理论研究,侧重于液体-蒸汽过渡线和任何新的阶段之间的关系。相图研究作为一个函数的吸引力的振幅为一定的固定幅度的长程排斥。我们发现斥力的作用是用两个一级相变代替汽液临界点和一部分汽液相变线。其中一个转变将蒸汽从球形类液簇的流体中分离出来;另一个转变将液体从球形空隙的流体中分离出来。在低温下,这两条转变线彼此相交,并且汽-液转变线相交于三相点。虽然大多数积分方程理论无法描述新的相变,Percus Yevick近似确实成功地捕捉到了蒸汽-团簇转变,以及团簇流体结构的各个方面,与模拟结果合理一致。

英文摘要:

Fluids in which the interparticle potential has a hard core, is attractive at moderate separations, and repulsive at greater separations are known to exhibit novel phase behavior, including stable inhomogeneous phases. Here we report a joint simulation and theoretical study of such a fluid, focusing on the relationship between the liquid-vapor transition line and any new phases. The phase diagram is studied as a function of the amplitude of the attraction for a certain fixed amplitude of the long ranged repulsion. We find that the effect of the repulsion is to substitute the liquid-vapor critical point and a portion of the associated liquid-vapor transition line, by two first order transitions. One of these transitions separates the vapor from a fluid of spherical liquidlike clusters; the other separates the liquid from a fluid of spherical voids. At low temperature, the two transition lines intersect one another and a vapor-liquid transition line at a triple point. While most integral equation theories are unable to describe the new phase transitions, the Percus Yevick approximation does succeed in capturing the vapor-cluster transition, as well as aspects of the structure of the cluster fluid, in reasonable agreement with the simulation results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑