Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia.
Institut für Theoretische Physik II: Soft Matter, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
J Chem Phys. 2019 Mar 14;150(10):104903. doi: 10.1063/1.5082785.
We study the phase diagram of a two-dimensional (2D) system of colloidal particles, interacting via an isotropic potential with a short-ranged Yukawa repulsion and a long-ranged dipolar attraction. Such interactions in 2D colloidal suspensions can be induced by rapidly rotating in-plane magnetic (or electric) fields. Using computer simulations and liquid integral equation theory, we calculate the bulk phase diagram, which contains gas, crystalline, liquid, and supercritical fluid phases. The densities at the critical and triple points in the phase diagram are governed by the softness of Yukawa repulsion and can therefore be largely tuned. We observe that the liquid-gas binodals exhibit universal behavior when the effective temperature (given by the inverse magnitude of the dipolar attractions) is normalized by its value at the critical point and the density is normalized by the squared Barker-Henderson diameter. The results can be verified in particle-resolved experiments with colloidal suspensions.
我们研究了通过各向同性势相互作用的二维（2D）胶体粒子系统的相图，该势具有短程 Yukawa 排斥和长程偶极吸引。在 2D 胶体悬浮液中，这种相互作用可以通过快速旋转面内磁场（或电场）来诱导。使用计算机模拟和液体积分方程理论，我们计算了包含气体、晶体、液体和超临界流体相的体相图。相图中的临界点和三相点的密度受 Yukawa 排斥的柔软度控制，因此可以进行大量调整。我们观察到，当有效温度（由偶极力的倒数给出）除以临界点的值，并且密度除以 Barker-Henderson 直径的平方时，液体-气体双值线表现出普遍行为。这些结果可以在具有胶体悬浮液的颗粒分辨实验中得到验证。
