报告题目：The contact aging scenario in adhesive colloidal suspensions
报 告 人：Anaël Lemaître 教授，法国Laboratoire Navier (Université Gustave Eiffel, CNRS, École des Ponts)
报告时间：2026年11月9日 周一14:00-15:00
报告地点：物理科技楼 101室
报告摘要：Moderately dense colloidal suspensions constitute a broad class of materials found in many areas, ranging from environmental systems (silts, clays), to industry (ceramics, drilling muds, slurries) and construction (cement), foodstuff, cosmetics, etc. They often display time-dependent rheological properties, such as mechanical aging, a non-saturating logarithmic growth of their shear modulus and yield stress at rest. Until recently, this behavior was attributed to the slow, glass-like, structural dynamics, which can be observed in transparent colloidal model systems. However, the conditions of transparency required in these studies also eliminate van der Waals attraction, which is otherwise one of the most pervasive forces at small scales. Most real-life suspensions are often opaque and ionic: these two conditions set the stage for the existence of adhesive forces that drive the formation of interparticle adhesive contacts. In an experimental study combining rheometry, confocal microscopy, and particle-scale mechanical tests using laser tweezers, we demonstrated that, in such systems at moderate densities, macroscopic aging is driven by time-dependent processes that take place at the contact scale. After presenting this general scenario, we will examine how it can be affected by a polymer admixture that adsorbs on particle surfaces.
报告人简介：Anaël Lemaître is a researcher at Laboratoire Navier (Université Gustave Eiffel, CNRS, École des Ponts, France) and Professor at École des Ponts. His research focuses on identifying the physical mechanisms underlying the mechanical behavior of disordered materials, including amorphous solids, granular media, and dense suspensions. He addresses these questions primarily by carrying out theoretical analyses and numerical simulations, while also engaging in and stimulating experimental investigations.
