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arXiv · 2608.21698

Non-uniform swelling of polyelectrolyte hydrogels: effects of charge regulation

Du Chen·Rudolph Podgornik·David Andelman·Xianghong Wang·Linli He·Shigeyuki Komura·Bin Zheng
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Abstract

We investigate the impact of charge regulation (CR) on the non-uniform swelling behavior of polyelectrolyte hydrogels. The Poisson-Boltzmann theory with electro-elastic coupling between the local polymer density and elastic deformation is considered. We investigate the spatial distributions of the elastic displacement and polymer density under different salt concentrations and compare charge-regulated gels with fixed-charge (non-CR) gels of the same net charge. Our results show that the CR induces spatially varying charge fractions, which strengthen the electro-elastic response and lead to stronger non-uniform swelling compared with non-CR gels. These findings provide a theoretical basis for understanding and controlling non-uniform swelling in responsive polyelectrolyte hydrogels.

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Du Chen, Rudolph Podgornik, David Andelman, Xianghong Wang, Linli He, Shigeyuki Komura, Bin Zheng. 2026-08-22. Non-uniform swelling of polyelectrolyte hydrogels: effects of charge regulation. https://arxiv.org/abs/2608.21698

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