The incorporation of charge within in situ covalently gelling poly(oligo ethylene glycol methacrylate) (POEGMA) precursor polymers enables the fabrication of hydrogels that exhibit both pH-responsive swelling and tunable network structures due to multimechanism cross-linking interactions. The gelation times, swelling responses, degradation kinetics, and mechanics of the resulting gels were strongly influenced by both the type of charge(s) incorporated and pH, with both amphoteric gels and anionic gels showing clear evidence of dual network formation. While the amphoteric dual network was anticipated due to charge interactions, the mechanism of the 5-fold enhancement in mechanical properties observed with the anionic gel relative to the neutral gel was revealed by isothermal titration calorimetry and small-angle neutron scattering to relate to the formation of a zippered chain structure based on dipole–dipole interactions. Consequently, rational design of the chemistry and the microscopic network structure results in controllable macroscopic properties amenable to potential biomedical applications.

中文翻译：

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pH离子化的原位胶凝聚（低聚乙二醇甲基丙烯酸甲酯）基水凝胶：内部网络结构在控制宏观性能中的作用

将电荷并入原位共价凝胶化聚甲基丙烯酸低聚乙二醇酯（POEGMA）的前体聚合物能够制造出水凝胶，该水凝胶由于多机理交联相互作用而具有pH响应性溶胀和可调网络结构。所得凝胶的胶凝时间，溶胀反应，降解动力学和力学性质受掺入的电荷类型和pH值的强烈影响，两性凝胶和阴离子凝胶均显示出双重网络形成的明显证据。由于电荷相互作用，预计会出现两性双网络，等温滴定热法和小角中子散射揭示了阴离子凝胶相对于中性凝胶力学性能提高5倍的机理，这与基于偶极-偶极相互作用的拉链链结构的形成有关。因此，化学和微观网络结构的合理设计导致了可控的宏观特性，适合潜在的生物医学应用。