Tuning Thermal Memory and Dissipation in Colloidal Microgel Glasses via Particle Stiffness
Abstract
The Kovacs effect, characterized by nonlinear, path-dependent structural recovery, is a hallmark of glassy systems. In soft colloidal microgel glasses, particle stiffness governs deformation, swelling, rearrangement, and response to external stimuli, and thereby dictates the path-dependent structural recovery of these jammed non-equilibrium systems. To investigate this influence, microgels of different stiffnesses were synthesized by adjusting the concentration of the polar crosslinker, N, N methylenebisacrylamide (MBA). The relaxation of the storage and loss moduli was measured using oscillatory rheology under diverse temperature ramp rates, and cryo-FESEM imaging provided direct visualization of the underlying particle packing. While the rapid adaptability of soft particles and the kinetic arrest of stiff ones suppresses Kovacs asymmetry, intermediate-stiffness particles exhibit moderate thermoresponsivity, traversing distinct energy landscapes on heating and cooling to maximize asymmetry and dissipation. Cryo-FESEM micrographs, displaying gel-like networks in soft particle suspensions, dense packing in stiff particle suspensions, and disordered, compact structures in intermediate-stiffness systems, corroborate these findings. Our results demonstrate that intermediate-stiffness PNIPAM microgels optimize structural recovery, rendering them promising candidates for forming colloidal glasses, and establish Kovacs asymmetry as a robust probe of non-equilibrium dynamics in glassy systems.
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BibTeX
@misc{kawale2026tuning,
title = {{Tuning Thermal Memory and Dissipation in Colloidal Microgel Glasses via Particle Stiffness}},
author = {Sonali Vasant Kawale and Ranjini Bandyopadhyay},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.29389},
eprint = {2610.29389},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.29389},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Tuning Thermal Memory and Dissipation in Colloidal Microgel Glasses via Particle Stiffness
AU - Sonali Vasant Kawale
AU - Ranjini Bandyopadhyay
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.29389
UR - https://arxiv.org/abs/2610.29389
AB - The Kovacs effect, characterized by nonlinear, path-dependent structural recovery, is a hallmark of glassy systems. In soft colloidal microgel glasses, particle stiffness governs deformation, swelling, rearrangement, and response to external stimuli, and thereby dictates the path-dependent structural recovery of these jammed non-equilibrium systems. To investigate this influence, microgels of different stiffnesses were synthesized by adjusting the concentration of the polar crosslinker, N, N methylenebisacrylamide (MBA). The relaxation of the storage and loss moduli was measured using oscillatory rheology under diverse temperature ramp rates, and cryo-FESEM imaging provided direct visualization of the underlying particle packing. While the rapid adaptability of soft particles and the kinetic arrest of stiff ones suppresses Kovacs asymmetry, intermediate-stiffness particles exhibit moderate thermoresponsivity, traversing distinct energy landscapes on heating and cooling to maximize asymmetry and dissipation. Cryo-FESEM micrographs, displaying gel-like networks in soft particle suspensions, dense packing in stiff particle suspensions, and disordered, compact structures in intermediate-stiffness systems, corroborate these findings. Our results demonstrate that intermediate-stiffness PNIPAM microgels optimize structural recovery, rendering them promising candidates for forming colloidal glasses, and establish Kovacs asymmetry as a robust probe of non-equilibrium dynamics in glassy systems.
ER -