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arXiv · 2603.17180

Mesoscopic Modeling of Dynamic Tetra-PEG Hydrogel Networks

Pietro Miotti·Lucien Cousin·Mark W. Tibbitt·Igor V. Pivkin
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Abstract

We introduce a mesoscopic model of dynamic Tetra-PEG hydrogel networks based on a hybrid Dissipative Particle Dynamics/Monte Carlo (DPD/MC) approach. Polymer chains are described by Finite Extensible Nonlinear Elastic (FENE) potential, while reversible cross-links are modeled with Morse potential and Monte Carlo bond exchange governed by Bell's force-dependent kinetics. After systematic calibration against theory and experiments, the model reproduces the characteristic Maxwell-like viscoelastic response of these networks. In particular, the relaxation time follows the expected scaling, $\tau_R \propto \tau_b (p - p_{\text{gel}})$, and the simulated storage moduli agree with experimental rheology. The mesoscopic resolution allows for graph-based topological analysis, where Tetra-PEG molecules and cross-links are represented as nodes and edges, providing access to bond distributions, fraction of dangling chains, and size of percolating clusters that are challenging to measure experimentally. Comparison with permanent-network predictions further suggests that dynamic bond exchange can affect bond distributions and delay the formation of a system-spanning cluster. This model bridges macromolecular bond kinetics and macroscopic mechanical properties, providing a complementary tool for rational design of dynamic polymer networks.

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Pietro Miotti, Lucien Cousin, Mark W. Tibbitt, Igor V. Pivkin. 2026-03-17. Mesoscopic Modeling of Dynamic Tetra-PEG Hydrogel Networks. https://arxiv.org/abs/2603.17180

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