Prediction and Detection of Submolecularly-Ordered Fluid Phases

摘要建议编号：9313714 P.I.：Marc D.Donohue研究所：约翰霍普金斯大学研究令人感兴趣的复杂流体的行为，因为它们展示了一系列有趣的现象，并且因为可以利用这种行为的各种工业过程。这里提出的研究将促进我们对微结构流体中亚分子环境的了解。此外，还将进行实验来探测这些亚分子环境。在过去的二十年里，流体相热力学取得了重大进展；尽管有这些改进，大多数胶束溶液、液晶和微乳液的理论和预测处理都强烈依赖于微观有序化的特定物理模型。这项拟议的研究将使用一种新的技术(Kuespert和Donohue，1993a)来修改高级状态方程，以用于复杂流体来预测微相平衡，例如在胶束溶液和计算机模拟中观察到的微相平衡。还将开展一项定性和定量研究微相平衡的实验计划，重点是非侵入性光谱研究。用傅里叶变换红外光谱仪研究微观有序流体相的极性和极化率。利用在不同红外光谱带观察到的变色位移，研究将无序流体分离成两个或多个有序微相。这种微相的极性和极化率的量化将允许它们的组成的干扰。这样确定的组成将与理论预测的组成进行比较。作为对FTIR方法的交叉验证，将使用溶剂位移和稀土元素移动剂效应的核磁共振测量来估计微相之间的相分离。

ABSTRACT Proposal Number: 9313714 P.I.: Marc D. Donohue Institution: The Johns Hopkins University The behavior of complex fluids of interest because of the intriguing range of phenomena they exhibit and because of the variety of industrial processes that can take advantage of this behavior. The research proposed here will advance our knowledge of submolecular environments within a microstructured fluid. Additionally, experiments will be carried out to probe these submolecular environments. Over the past twenty years, significant advances in the thermodynamics of fluid phases have occurred; despite these improvements, most theoretical and predictive treatments of micellar solutions, liquid crystals, and microemulsions depend strongly on specific physical models of the microscopic ordering. The proposed research will employ a new technique (kuespert and Donohue, 1993a) to modify advanced equations-of-state for use with complex fluids to predict microphase equilibria such as those observed in micellar solutions and in computer simulations. An experimental program to qualitatively and quantitatively study microphase equilibria also will be conducted, focusing on nonintrusive spectrometric investigations. The polarity and polarizability of microscopically-ordered fluid phases will be examined using Fourier transform infrared spectrometry. Separation of a nonordered bulk fluid into two or more ordered microphases will be studied using that salvatochromic shifts observed in various IR spectral bands. Quantification of the polarity and polarizability of such microphases will allow interference of their compositions. The compositions thus determined then will be compared with those predicted by theory. As a cross-check on the FTIR methods, nuclear magnetic resonance measurements of solvent shifts and lanthanide shift reagent effects will be used to estimate the phase splits between microphases.