Diffusio-phoretic fast swelling of chemically responsive hydrogels
Abstract
Acid-induced release of stored ions from polyacrylic acid hydrogels (with a free surface fully permeable to the ion and acid flux) was observed to increase the gel osmotic pressure that leads to rapid, temporary swelling faster than the characteristic solvent absorption rate of the gel. Here we develop a continuum poroelastic theory that quantitatively explains the experiments by introducing a "gel diffusio-phoresis" mechanism: Steric repulsion between the gel polymers and released ions can induce a diffusio-osmotic solvent intake counteracted by the diffusio-phoretic expansion of the gel network. For applications ranging from drug delivery to soft robotics, engineering the gel diffusio-phoresis may enable stimuli-responsive hydrogels with amplified strain rates and power output.
Cite
@article{arxiv.2309.05165,
title = {Diffusio-phoretic fast swelling of chemically responsive hydrogels},
author = {Chinmay Katke and Peter A. Korevaar and C. Nadir Kaplan},
journal= {arXiv preprint arXiv:2309.05165},
year = {2024}
}
Comments
The proposed gel diffusio-phoresis mechanism is detailed on p. 1, column 2, and in the revised Figure 1 (along with its revised caption). We have added additional statements to explain the contributions to the equations that were not specified in the previous version (p.2, 1st column, 2nd paragraph; p.3, 1st column, following Eqs.5, 6, and 7). New supplementary sections S1 and S4 are added