González García Álvaro, Tuinier Remco
Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands and Van't Hoff Laboratory for Physical and Colloid Chemistry, Department of Chemistry & Debye Institute, Utrecht University, Padualaan 8, 3584 CH, The Netherlands.
Phys Rev E. 2016 Dec;94(6-1):062607. doi: 10.1103/PhysRevE.94.062607. Epub 2016 Dec 16.
Theory that predicts the phase behavior of interacting Yukawa spheres in a solution containing nonadsorbing polymer is presented. Our approach accounts for multiple overlap of depletion zones. It is found that additional Yukawa interactions beyond hard core interactions strongly affect the location and presence of coexistence regions and phase states. The theoretical phase diagrams are compared with Monte Carlo simulations. The agreement between the two approaches supports the validity of the theoretical approximations made and confirms that, by choosing the parameters of the interaction potentials, tuning of the binodals is possible. The critical end point characterizes the phase diagram topology. It is demonstrated how an additional Yukawa interaction shifts this point with respect to the hard sphere case. Provided a certain depletant-to-colloid size ratio for which a stable colloidal gas-liquid phase coexistence takes place for hard spheres, added direct interactions turn this into a metastable gas-liquid equilibrium. The opposite case, the induction of a stable gas-liquid coexistence where only fluid-solid was present for hard spheres, is also reported.
提出了一种预测在含有非吸附性聚合物的溶液中相互作用的汤川球的相行为的理论。我们的方法考虑了耗尽区的多重重叠。结果发现，除硬核相互作用之外的额外汤川相互作用强烈影响共存区域和相态的位置及存在情况。将理论相图与蒙特卡罗模拟进行了比较。两种方法之间的一致性支持了所做理论近似的有效性，并证实通过选择相互作用势的参数，可以对双节线进行调控。临界终点表征了相图拓扑结构。展示了额外的汤川相互作用相对于硬球情形如何使该点发生移动。对于硬球而言，当存在一定的贫化剂与胶体尺寸比时会发生稳定的胶体气 - 液相共存，加入直接相互作用会将其转变为亚稳的气 - 液平衡。还报道了相反的情况，即对于硬球仅存在流 - 固共存时诱导出稳定的气 - 液共存。
