溶质相互作用与界面性质的关联
Relating solute interactions to interfacial properties
- Technical University of Darmstadt（达姆施塔特工业大学）
- The Pennsylvania State University（宾夕法尼亚州立大学）
- Princeton University（普林斯顿大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究构建稀溶液理论（DST），结合巨正则微扰理论与吉布斯系综，通过分子动力学模拟验证，揭示溶质相互作用对液-气相界面性质的影响。
AI中文摘要：
液体界面广泛存在于诸多商业产品、现代技术、生物过程及环境现象中，其性质对体相液相的组成十分敏感。本研究针对稀溶液溶质对共存液-气相界面的影响，构建了稀溶液理论（DST）；采用巨正则微扰理论，严格关联界面自由能与溶液浓度；借助对应吉布斯系综处理液-气共存，消除体相对该自由能的贡献；将所得展开式的系数以微观配分函数表示。通过最低阶处理溶质-溶质相互作用，区分了溶质的本征界面偏好与有效界面偏好：前者仅反映溶质-溶剂相互作用，后者则依赖溶液组成，体现溶质-溶质相互作用的影响。以Lennard-Jones球的二元及三元混合物的分子动力学模拟评估该DST，结果表明，DST可准确描述这些体系在相对高浓度下的界面性质；此外，模拟还显示，吸引性的溶质-溶质相互作用可将弱本征表面活性剂转化为弱有效耗散剂。
英文摘要：
Liquid interfaces are both ubiquitous and also critically important for many commercial products, modern technologies, biological processes, and environmental phenomena. The properties of these interfaces can depend quite sensitively upon the composition of the bulk liquid phase. In this work, we develop a dilute solution theory (DST) for the influence of dilute cosolutes upon the interface between coexisting liquid and vapor phases. We employ a grand canonical perturbation theory to rigorously relate the interfacial free energy to the concentration of the liquid solution. We leverage a corresponding Gibbs ensemble to treat liquid-vapor coexistence and to eliminate the contribution of the bulk phases from this free energy. We express the coefficients of the resulting expansion in terms of microscopic partition functions. By treating solute-solute interactions to lowest order, we distinguish between the intrinsic and effective interfacial preferences of solutes. While the former reflects only solute-solvent interactions, the latter depends upon the solution composition and reflects the influence of solute-solute interactions. We assess this DST with molecular dynamics simulations of binary and ternary mixtures of Lennard-Jones spheres. These simulations demonstrate that DST accurately models the interfacial properties of these systems up to relatively high concentrations. Moreover, the simulations illustrate the impact of attractive solute-solute interactions in converting weak intrinsic surfactants into weak effective depletants.
