(129f) Understanding Three Transition States of Zwitterionic Carboxybetaine Methacrylate Hydrogels through Molecular Simulations

In order to improve the performance of carboxybetaine methacrylate (CBMA) hydrogel, a CBMA polymer network was modified by introducing one hydroxyl group to the carbon atom between positive and negative groups in each CBMA repeat unit. We observed that additional physical crosslinkers formed between hydroxyl groups and carboxylate groups. We also studied the physical properties of the hydrogel at various water contents. A series of all-atom hydrogel models were built by using the modified CBMA repeat unit. These models contain different amount of water molecules, ranging from 20% to 90% of the total weight of the hydrogels. Molecular dynamics simulations were performed to study the properties of the hydrogels. The hydrogel groups The results show that three transition states of hydrogel can be observed as the water content of hydrogel gets larger. These transitions can be directly correlated to the diffusion coefficient of water, the lifetime of physical crosslinkers, and the chemical crosslinkers in the polymer network. These results are comparable to previously published experimental studies about similar zwitterionic hydrogels.