Interactions and Self-Assembly of Particles in Complex Fluids

该奖项支持复杂流体的理论和计算研究。PI的目标是结合联合收割机场理论和基于粒子的方法，开发混合模拟工具，可用于研究热力学和复杂流体中的粒子自组装。这些混合技术可以解释复杂流体介质中颗粒分散体的不同长度尺度，同时有效地结合空间和短程相互作用。提出了两类研究和工具：（1）场论模拟（FTS），最近开发的PI的方法，将用于系统地评估在不同的复杂流体中的任意几何形状的颗粒之间的相互作用。结果可能会产生根本的见解不同的因素，影响波动引起的力量，特别是，他们的nonpairwise添加剂的性质，以及之间的相互作用充满活力的（所产生的复杂的流体和粒子表面之间的物理相互作用）和熵的相互作用。这些研究的结果也将用于实现粒子的真空模拟，以便深入了解粒子的自组装特征。(2)PI将开发一种混合多体模拟方法，用于复杂流体中粒子的自组装。在每一步的场的FTS和平均场方程的组合确定刚性单元之间的有效相互作用。这些有效的相互作用将用于通过基于粒子的模拟来"演化"刚性单元。 这些研究的目的是澄清多体相互作用的作用，nonpairwise相加力和排除体积相互作用在调制的各种复杂的流体和粒子的混合物的自组装。该研究将在聚合物-颗粒混合物、电荷稳定的胶体分散体和多嵌段棒-线圈共聚物中的相互作用和自组装研究的背景下进行。这些都是理想的模型系统，在其中研究有关波动，自组装和动力学的影响。这些中的每一个都可以通过定制合成条件以受控的方式独立地调节。这种能力允许与实验研究进行协同互动，以比较预测和实验。在每个模型系统中，PI计划进行研究，通过一个共同的目标联系起来，以识别空间和能量相互作用之间的竞争所产生的自组装，以及双晶/近晶有序之间的相互作用，这些混合模拟方法的成功实施预计将对多尺度计算方法的发展产生重大影响，先进材料的设计。该奖项支持复杂流体的理论和计算研究和教育。PI的目标是联合收割机不同的和强大的计算方法，开发混合模拟工具，可用于研究热力学和复杂流体中的粒子自组装。这些工具将用于研究聚合物颗粒混合物，电荷稳定的胶体分散体和多嵌段棒-线圈聚合物中的相互作用和自组装，以阐明复杂流体物理学中的重要问题。模拟工具还有助于使用理论方法来预测由特定分子参数产生的先进材料的形态特征和性能。***

This award supports theoretical and computational research on complex fluids. The PI aims to combine field-theoretic and particle-based approaches to develop hybrid simulation tools that can be used to study the thermodynamics and self-assembly of particles in complex fluids. These hybrid techniques can account for the disparate length scales accompanying particle dispersions in complex fluid media, while efficiently incorporating steric and short-range interactions. Two classes of studies and tools are proposed: (1) Field-Theoretic Simulations (FTS), an approach recently developed by the PI, will be used to systematically evaluate the interactions between particles of arbitrary geometries in different complex fluids. The results may yield fundamental insights into the different factors that influence fluctuation-induced forces, in particular, their nonpairwise additive nature, as well as the interplay between energetic (arising from a physical interaction between the complex fluid and the surface of the particle) and entropic interactions. The results from these studies will also be used in effecting an in vacuo simulation of the particles, in order to glean insights into the self-assembly features of the particles. (2) The PI will develop a hybrid multibody simulation approach to the self-assembly of particles in complex fluids. A combination of FTS and mean-field equations for the fields at every step determines the effective interactions between the rigid units. These effective interactions will be used to "evolve" the rigid units through a particle-based simulation. The studies are aimed to clarify the role of multibody interactions, nonpairwise additivity of forces and excluded volume interactions in modulating the self-assembly of a variety of mixtures of complex fluids and particles. The research will be effected in the context of studies of the interactions and self-assembly in polymer-particle mixtures, charge stabilized colloidal dispersions, and multiblock rod-coil copolymers. These are ideal model systems in which to study effects pertaining to fluctuations, self-assembly, and dynamics. Each of these can be tuned independently and in a controlled way by tailoring the synthesis conditions. This capability allows for a synergistic interaction with experimental studies to compare predictions and experiments. In each of these model systems, the PI plans to carry out studies, linked by a common objective, to discern the self-assembly arising from a competition between steric and energetic interactions, as well as the interplay between nematic/smectic ordering, crystallization and microphase separation.The successful implementation of these hybrid simulation approaches is expected to have significant impact on the development of multiscale computational approaches to the design of advanced materials.%%%This award supports theoretical and computational research and education on complex fluids. The PI aims to combine distinct and powerful computational approaches to develop hybrid simulation tools that can be used to study the thermodynamics and self-assembly of particles in complex fluids. These tools will be used to study the interactions and self-assembly in polymer-particle mixtures, charge stabilized colloidal dispersions, and multiblock rod-coil polymers to elucidate important issues in the physics of complex fluids. The simulation tools also contribute to efforts to use theoretical methodology to predict the morphological characteristics and properties of advanced materials that result from specific molecular parameters. ***