Dudka Maxym, Kondrat Svyatoslav, Kornyshev Alexei, Oshanin Gleb
Institute for Condensed Matter Physics, 1 Svientsitskii str., 79011 Lviv, Ukraine.
J Phys Condens Matter. 2016 Nov 23;28(46):464007. doi: 10.1088/0953-8984/28/46/464007. Epub 2016 Sep 14.
The ion-ion interactions become exponentially screened for ions confined in ultranarrow metallic pores. To study the phase behaviour of an assembly of such ions, called a superionic liquid, we develop a statistical theory formulated on bipartite lattices, which allows an analytical solution within the Bethe-lattice approach. Our solution predicts the existence of ordered and disordered phases in which ions form a crystal-like structure and a homogeneous mixture, respectively. The transition between these two phases can potentially be first or second order, depending on the ion diameter, degree of confinement and pore ionophobicity. We supplement our analytical results by three-dimensional off-lattice Monte Carlo simulations of an ionic liquid in slit nanopores. The simulations predict formation of ionic clusters and ordered snake-like patterns, leading to characteristic close-standing peaks in the cation-cation and anion-anion radial distribution functions.
对于限制在超窄金属孔中的离子，离子-离子相互作用会受到指数屏蔽。为了研究这种被称为超离子液体的离子集合体的相行为，我们发展了一种基于二分晶格的统计理论，该理论在贝特晶格方法内允许解析解。我们的解预测了有序相和无序相的存在，在有序相中离子分别形成类似晶体的结构，在无序相中形成均匀混合物。这两个相之间的转变可能是一级或二级的，这取决于离子直径、限制程度和孔的憎离子性。我们通过对狭缝纳米孔中离子液体的三维非晶格蒙特卡罗模拟来补充我们的解析结果。模拟预测了离子簇的形成和有序的蛇状图案，导致阳离子-阳离子和阴离子-阴离子径向分布函数中出现特征性的紧密峰。
