Statistical Mechanics of Ordered Fluids and Almost-ideal Solids

William Gelbart得到了理论与计算化学项目的资助，继续他在两亲动物统计力学处理方面的工作。他正在研究两亲体在水中的自组织性质和相变随浓度的变化。确定了三个新的研究领域：a)水体系中浓缩表面活性剂胶束大小/形状与长程序的耦合；B)柔性胶束溶液的结构和流动特性；c)应力作用下几乎理想固体的统计力学。Gelbart使用了大量的分析方法，包括密度泛函理论、平均场近似、重整化群方法和类自旋矢量哈密顿方法，并在少数情况下辅以蒙特卡罗和分子动力学模拟。两亲分子是长链状分子，一端具有水溶性极性基团，另一端具有油性烃基团。两亲化合物被广泛用作表面活性剂和洗涤剂。这些分子倾向于在溶液中聚集在一起，并自组织成层或胶束，胶束是封闭的表面，极性基团在外面，长链油部分在里面。两亲植物有广泛的工业和商业用途。Gelbart的理论研究将帮助我们更好地理解这类重要化合物的物理化学性质，并设计出更好的这类材料。

William Gelbart is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work in statistical mechanical treatment of amphiphiles. He is studying the self-organizing properties and phase transitions of amphiphiles in water as a function of concentration. Three areas of new study are identified: a) coupling between micellar size/shape and long range order in concentrated surfactant in water systems; b) structures and flow properties of solutions of flexible micelles; and c) statistical mechanics of almost ideal solids under stress. Gelbart is using a whole host of analytical methodologies including density functional theory, mean field approximation, renormalization group approaches, and spin- vector-like Hamiltonian approaches supplemented in a few cases with Monte Carlo and molecular dynamics simulations. %%% Amphiphiles are long chainlike molecules which have water soluble polar groups at one end and oily hydrocarbon groups at the other end. Amphiphiles find widespread use as surfactants and detergents. These molecules tend to aggregate together in solution and self-organize into layers or micelles which are enclosed surfaces having the polar groups on the outside, and the long chain oily portions on the inside. Amphiphiles have widespread industrial and commercial use. Gelbart's theoretical research will help us to better understand the physical chemistry of this important class of chemical compounds, and to design even better materials of this type.