Near-surface colloidal dynamics in jammed and slipping microgel suspensions
Abstract
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.
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BibTeX
@misc{gunny2026nearsurface,
title = {{Near-surface colloidal dynamics in jammed and slipping microgel suspensions}},
author = {Masoodah Gunny and Frédérick Caetano and Matilde Bureau and Alexandre Vilquin and Marie Le Merrer and Joshua D Mcgraw and Catherine Barentin},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.03540},
eprint = {2609.03540},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.03540},
}
RIS
TY - UNPB
TI - Near-surface colloidal dynamics in jammed and slipping microgel suspensions
AU - Masoodah Gunny
AU - Frédérick Caetano
AU - Matilde Bureau
AU - Alexandre Vilquin
AU - Marie Le Merrer
AU - Joshua D Mcgraw
AU - Catherine Barentin
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2609.03540
UR - https://arxiv.org/abs/2609.03540
AB - 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.
ER -