Theory of Fluids, Phase Transitions, and Interfaces

康奈尔大学的Ben Widom得到了理论和计算化学计划的支持，继续他对流体、相变和界面的研究。他将使用统计力学方法研究液体和液体混合物的性质，这种流体经历的相变，以及流体相之间界面的热力学和结构变化。将探讨五个研究课题：1)二元相分离液体混合物界面张力的模拟；2)疏水相互作用的一维模型向更高维和更类似水的溶剂的扩展；3)对最近关于碳氢化合物在水上扩散的两阶段润湿转变的意外实验观察的理论处理；4)确定表面活性剂的存在对界面结构波动的影响的研究；5)与荷兰研究人员合作分析混合胶体和聚合物的实验结果。在实验室和工业实践中，经常需要预测相分离液体混合物的界面张力。本研究项目针对双组分混合物中的界面张力进行研究。水溶液中两个非极性疏水分子之间的有效吸引是物理化学和生物学中一个基本且被广泛研究的现象。最近提出的一个模型表明疏水吸引的范围和强度之间存在反向关系，这项工作将把该模型扩展到更高的维度，并包括更多的类似水的溶剂行为。与实验者的合作将分析混合胶体和聚合物的结果。

Ben Widom of Cornell University is supported by the Theoretical and Computational Chemistry Program to continue his research on fluids, phase transitions, and interfaces. He will employ statistical mechanical methods to study the properties of liquids and liquid mixtures, the phase transitions that such fluids undergo, and the thermodynamics and structural transformations of the interfaces between fluid phases. Five research topics will be explored: 1) modeling of interfacial tensions of binary phase-separated liquid mixtures; 2) an extension of a one-dimensional model for hydrophobic interaction to higher dimensions and more water-like solvent; 3) a theoretical treatment of a recent unexpected experimental observation regarding the two-stage wetting transition for the temperature dependence of hydrocarbon spreading on water; 4) a study to determine the effect of the presence of surfactants on the fluctuations in the structure of interfaces; 5) a collaborative study with researchers from the Netherlands to analyze experimental results on mixed colloids and polymers.Both in the laboratory and in industrial practice it is often necessary to predict the interfacial tensions of phase-separated liquid mixtures. This research project address the interfacial tensions in two-component mixtures. The effective attraction between two nonpolar, hydrophobic molecules in a water solution is a fundamental and much studied phenomenon in physical chemistry and biology. A recently proposed model suggests an inverse relation between the range and strength of the hydrophobic attraction, and this work will extend that model to higher dimensions and include more "water-like" solvent behavior. Collaborative work with experimentalists will analyze results on mixed colloids and polymers.