Theory of Nonuniform Fluids

马里兰大学的约翰·威克斯得到了理论和计算化学项目的支持，该项目研究非均匀流体的性质。这项工作集中在离子系统，并涉及以下主题：1)离子液体理论的研究，重点是分子和中间长度尺度发挥重要作用的区域以及长程库仑相互作用，2)疏水相互作用理论的进一步发展和应用到描述疏水和亲水表面附近水的密度分布的新实验，3)详细检查这一新的理论方法与密度泛函理论之间的关系，以及4)通过结合体相系统的已知数据和精确求和规则在理论中发展新的技术扩展和改进。这可能是某些应用中定量结果所必需的，特别是离子液体，并有望促进利用实验数据来帮助发现新的定性效应的简单半经验方法的发展。非均匀流体领域的问题由于其在生物物理和工业应用中的实际重要性而引起了极大的兴趣。实验表明，非均匀简单流体的静态和动态性质，特别是当限制在小孔或狭缝中时，与均匀体系的静态和动态性质有很大的不同。含有盐和蛋白质等离子的非均匀溶液在生物过程中起着关键作用。与双层形成相关的不均匀的电荷分布被认为是稳定大分子和胶体的水溶液。

John Weeks of the University of Maryland is supported by the Theoretical and Computational Chemistry Program to investigate the properties of nonuniform fluids. This work concentrates on ionic systems, and addresses the following topics: 1) research in the theory of ionic liquids focusing on regimes where molecular and intermediate length scales play an important role along with long-range Coulomb interactions, 2) further development of the theory of hydrophobic interactions and application to new experiments describing the density distribution of water near hydrophobic and hydrophilic surfaces, 3) detailed examination of the relationship between this new theoretical approach and density functional theory, and 4) development of new technical extensions and improvements in the theory by incorporating known data for bulk systems and exact sum rules. This may be required for quantitative results in some of the applications, ionic liquids in particular, and is expected to facilitate the development of simple semi-empirical approaches that make use of experimental data to help uncover new qualitative effects.Problems in the area of nonuniform fluids are of great current interest due to their practical importance in biophysical and industrial applications. Experiments have shown that the static and dynamic properties of nonuniform simple fluids, particularly when confined to small pores or slits, differ dramatically from those of uniform systems. Nonuniform solutions containing ions such as salts and proteins play a key role in biological processes. The nonuniform charge distribution associated with double layer formation is believed to stabilize aqueous solutions of macromolecules and colloids.