发表机构
PSL Research University, ESPCI Paris; Université Lyon 1（巴黎文理研究大学，巴黎高等物理化工学院; 里昂第一大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究借助全内反射荧光显微镜（TIRFM）观测微凝胶悬浮液近表面胶体动力学，证实近壁异质性是微凝胶壁滑移的主要机制，为相关研究开辟了新视角。
AI 中文摘要
软微凝胶颗粒的阻塞悬浮液可能沿光滑边界发生滑移，由于其预期的亚微米尺寸，对被认为是该滑移原因的近表面层内动力学的直接观测一直难以实现。本研究采用全内反射荧光显微镜（TIRFM）观测玻璃/微凝胶悬浮液界面附近的纳米颗粒动力学，悬浮液的速度分布呈非线性，表明存在近壁动态异质性；这些分布在距壁亚微米距离处趋于恒定滑移速度，与宏观壁滑移测量结果一致。此外，纳米级颗粒高度分布强烈依赖于滑移速度，揭示了动态介导的纳米级颗粒组织效应。收集到的观测结果支持近壁异质性是微凝胶壁滑移的主要机制，本研究也为复杂界面环境中颗粒动力学与组织的研究开辟了新视角。
英文摘要
Jammed suspensions of soft microgel particles may exhibit slippage along smooth boundaries. Owing to their expected sub-micrometric dimensions, direct observations of dynamics within the near-surface layers supposed to be responsible for this slippage have been difficult to achieve. Here, we use total internal reflection fluorescence microscopy (TIRFM) to observe nanoparticle dynamics near glass/microgel-suspension interfaces. Indicating near-wall dynamic heterogeneity, velocity profiles for suspensions are nonlinear. These profiles tend to a constant slippage velocity at submicrometric distances from the wall, consistent with macroscopic wall slip measurements. Furthermore, nanoscale particle altitude distributions are strongly dependent on the slip velocity, revealing a dynamically-mediated and nanoscale particle-organisation effect. The collected observations give support for the existence of near-wall heterogeneity as a dominant mechanism contributing to microgel wall slip. Our work also opens new perspectives for the study of particle dynamics and organisation in complex interfacial environments.
