Quasi-Two Dimensional Colloid Suspensions

斯图尔特·赖斯是由理论和计算化学计划的资助，以执行准二维系统的性质的实验和理论研究。 待研究的系统是不带电的单分散胶体颗粒在非常薄的细胞中的悬浮液。 拟议的实验研究将基于数字视频显微镜测量，并将使用光镊进行捕获实验。 理论模拟将用于扩展胶体悬浮液中的运输理论，以包括结构波动。 密度泛函理论的各种应用也将被用来研究准二维系统的相图。 具体的问题包括：1）准二维相结构的变化，以及这些相之间的转变作为与约束相关的约束的函数的特征; 2）弛豫过程的密度依赖性，以及玻璃形成的开始; 3）准二维到三维约束的转变如何影响胶体悬浮液中的弛豫过程;（4）胶体-胶体相互作用的范围对准二维悬浮液的结构和动力学行为的影响，这些研究将有助于更深入地理解液体系统的性质，因为它们被限制在二维运动中，表现出独特的热力学行为。 这项工作可能在新材料或专用设备的开发中具有重要的应用。

Stuart Rice is supported by a grant from the Theoretical and Computational Chemistry Program to perform experimental and theoretical studies of the properties of quasi-two dimensional systems. The systems to be studied are suspensions of uncharged monodisperse colloid particles in very thin cells. The proposed experimental studies will be based on digital video microscopy measurements, and use will be made of an optical tweezer to perform trapping experiments. Theoretical simulations will be used to extend the theory of transport in colloid suspensions to include structural fluctuations. Various applications of density functional theory will also be used to study the phase diagram of quasi-two dimensional systems. Particular questions to be addressed include: 1) the changes induced in structures of quasi-two dimensional phases, and the character of the transitions between those phases as a function of constraints associated with confinement; 2) the density dependence of the relaxation processes, and the onset of glass formation; 3) how relaxation processes in colloid suspensions are influenced by a transition from quasi-two dimensional to three dimensional confinement; and 4) how the range of colloid-colloid interaction influences the structure and dynamical behavior of quasi-two dimensional suspensions.The proposed studies will lead to a deeper understanding of the properties of liquid systems that, because they are constrained to two dimensional motion, exhibit unique thermodynamic behavior. This work may have important applications in the development of new materials or specialized devices.