Investigation of the dynamics of geometrically restricted soft matter systems with long-ranged interactions

我们提出了一个系统的理论和实验研究几何限制软物质系统的动力学与远程排斥和吸引相互作用。作为研究的主要系统，我们将使用在流体界面上被重力捕获的超顺磁性胶体粒子。对于这种粒径在几十微米以上的胶体，粒子之间存在一种类似于二维屏蔽牛顿引力的远程毛细相互作用，结合由外磁场诱导的排斥偶极子-偶极子相互作用，为研究存在远程吸引力时的动力学和结构形成提供了一种新的模型系统。特别的重点将放在低维设置，系统的外部几何约束及其对动力学的影响。此外，流体动力学相互作用预计会在准二维系统中表现出特殊的特征，因为二维粒子层与真正的，但几何上受限制的三维溶剂之间的相互作用预计会与真正的二维或三维设置有很大不同。拟议的项目涵盖同一系统的实验和理论工作，并进行密切合作，从而为理论和实验带来额外的互利和富有成效的投入。

We propose a systematic theoretical and experimental study of the dynamics of geometrically restricted soft matter systems with long-ranged repulsive and attractive interactions. As major system for investigation, we will use superparamagnetic colloidal particles trapped by gravity at a fluid interface. For such colloids with sizes above a tens of micrometers, the presence of a long-ranged capillary interaction among the particles, an analogue to screened Newtonian gravity in two dimensions, combined with repulsive dipole-dipole interactions induced by an external magnetic field, provides a new model system for the study of dynamics and structure formation in the presence of long-ranged attractions. Special focus will be on the low-dimensional setup, external geometric constraints of the system and their consequences on the dynamics. Additionally, hydrodynamic interactions are expected to exhibit special features in quasi two-dimensional systems, as the interplay between the two-dimensional layer of particles and the genuine, but geometrically restricted three-dimensional solvent is expected to differ significantly from genuinely two- or three-dimensional setups. The proposed project covers experimental and theoretical work on the same system and in close collaboration, resulting in additional mutual benefits and fruitful input for both, theory and experiment.