Structure and Dynamics of Composite, Fluid Interfaces

该研究将研究由胶体颗粒和两亲分子组合组成的复合流体界面的动力学和结构。不对称粒子的二维悬浮液也将被研究。由于许多商业和自然存在的系统（乳剂、泡沫和肺中的肺泡）是两亲性材料的复杂混合物，因此对其界面流变学的基本理解对于提高产品性能和治疗程序至关重要。这项工作主要是实验性的，将利用我们实验室开发的新的测量方法（界面流变学，界面流动显微镜）来揭示界面微观结构和界面流变学之间的关系。这项工作将集中在由与分子两亲体共存的胶体粒子组成的移动界面上。这导致二维悬浮液预计具有独特的流变特性。除了球形，胶体颗粒，长形和扁形颗粒将被研究，因为这些系统提供了模仿脂肪酸和醇的可能性，其中位置和方向顺序聚集在一起，创建复杂的二维相图。知识价值。复杂流体界面的分类方法与复杂流体界面（二维熔体、溶液、悬浮液等）相似。事实上，将分子和粒子限制在二维空间往往会增加流变非线性。然而，大多数物理系统是两亲性成分的混合物，但很少有人在这方面给予注意。这里计划的实验将提供第一个二维悬浮液的系统数据，其中颗粒收集在非牛顿分子两亲体的单层内。更广泛的影响。复杂、复合单层的界面流变学对许多商业活动都很重要，例如食品和个人产品的加工。这些系统通常以需要稳定的乳液和泡沫的形式存在。此外，胶体系统是研究基本物理现象的有用模型系统，在这种情况下，由不对称颗粒组成的二维单层将用于模拟脂肪酸和磷脂的富相行为。

The proposed research will investigate the dynamics and structure of composite, fluid interfaces comprised of combinations of colloidal particles and molecular amphiphiles. Two-dimensional suspensions of asymmetric particles will also be studied. Since many commercial and naturally occurring systems (emulsions, foams, and the alveoli in our lungs) are complex mixtures of amphiphilic materials, fundamental understanding of their interfacial rheology is central to advancing the performance of products and treatment procedures.This work, which is primarily experimental, will take advantage of new measurement methods developed in our laboratory (interfacial rheometry, interfacial flow-microscopy) to reveal the relationship between interfacial microstructure and interfacial rheology. This work will focus on mobile interfaces comprised of colloidal particles that coexist with molecular amphiphiles. This results in two-dimensional suspensions that are expected to have a unique rheological character. In addition to spherical, colloidal particles, prolate and oblate particles will be studied since these systems offer the possibility of mimicking fatty acids and alcohols where positional and orientational order come together to create complex 2D phase diagrams. Intellectual merit. Complex fluid interfaces can be classified in ways that are similar to their complex fluid counterparts (2D melts, solutions, suspensions, etc.). Indeed, restricting molecules and particles to two dimensions often increases rheological nonlinearities. Most physical systems, however, are mixtures of amphiphilic constituents, but little attention has been offered in this direction. The experiments planned here will provide the first systematic data on two-dimensional suspensions where particles are collected within monolayers on nonNewtonian, molecular amphiphiles.Broader impacts. The interfacial rheology of complex, composite monolayers is important to many commercial activities, such as the processing of food products and personal products.These systems are often in the form of emulsions and foams that require stabilization. Furthermore, colloidal systems are useful model systems for the study of basic physical phenomena and in this case two-dimensional monolayers comprised of asymmetric particles will be used to mimic the rich phase behavior of fatty acids and phospholipids.