Roughness Induced Rotational Slowdown Near the Colloidal Glass Transition

粗糙胶体椭球单层中的玻璃化转变

Glass Transition in Monolayers of Rough Colloidal Ellipsoids

本研究通过胶体实验与粗粒化模拟，发现表面粗糙度可消除光滑椭球单层中的取向玻璃和两步玻璃化转变，并破坏结构-动力学关联，为调控胶体玻璃化转变提供了新途径。

Jamming Distance Dictates Colloidal Shear Thickening

We report experimental and computational observations of dynamic contact networks for colloidal suspensions undergoing shear thickening. The dense suspensions are comprised of sterically stabilized poly(methyl methacrylate) hard sphere colloids that are spherically symmetric and have varied surface roughness. Confocal rheometry and dissipative particle dynamics simulations show that the shear thickening strength scales exponentially with the scaled deficit contact number and the scaled jamming distance. Rough colloids, which experience additional tangential and rolling constraints, require an …

Structures and dynamics of glass-forming colloidal liquids under spherical confinement

Recent theories predict that when a supercooled liquid approaches the glass transition, particle clusters with a special "amorphous order" nucleate within the liquid, which lead to static correlations dictating the dramatic slowdown of liquid relaxation. The prediction, however, has yet to be verified in 3D experiments. Here, we design a colloidal system, where particles are confined inside spherical cavities with an amorphous layer of particles pinned at the boundary. Using this novel system, we capture the amorphous-order particle clusters and demonstrate the development of a static correlat…

Sedimentation of a Colloidal Monolayer Down an Inclined Plane

We study the driven collective dynamics of a colloidal monolayer sedimentating down an inclined plane. The action of the gravity force parallel to the bottom wall creates a flow around each colloid, and the hydrodynamic interactions among the colloids accelerate the sedimentation as the local density increases. This leads to the creation of a universal "triangular" inhomogeneous density profile, with a traveling density shock at the leading front moving in the downhill direction. Unlike density shocks in a colloidal monolayer driven by applied torques rather than forces [Phys. Rev. Fluids, 2(9…

基于表面化学的胶体颗粒扩散泳与扩散渗流连续分离

Surface Chemistry-based Continuous Separation of Colloidal Particles via Diffusiophoresis and Diffusioosmosis

本研究利用扩散泳和扩散渗流，在双结微流控装置中通过盐浓度梯度，实现了表面羧基浓度不同但尺寸和ζ电位相似的胶体颗粒的100%效率连续分离。

Hydrodynamic Correlations slow down Crystallization of Soft Colloids

Crystallization is often assumed to be a quasi-static process that is unaffected by details of particle transport other than the bulk diffusion coefficient. Therefore colloidal suspensions are frequently argued to be an ideal toy model for experimentally more difficult systems such as metal melts. In this letter, we want to challenge this assumption. To this aim, we have considered molecular dynamics simulations of the crystallization in a suspension of Yukawa-type colloids. In order to investigate the role of hydrodynamic interactions (HIs) mediated by the solvent, we modeled the solvent both…