Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
J Mater Chem B. 2019 Mar 14;7(10):1690-1696. doi: 10.1039/C8TB02854K. Epub 2018 Dec 13.
Catechol-bearing polymers form hydrogel networks through cooperative oxidative crosslinking and coordination chemistry. Here we describe the kinetics of cation-dependent electrochemical-mediated gelation of precursor solutions composed of catechol functionalized four-arm poly(ethylene glycol) combined with select metal cations. The gelation kinetics, mechanical properties, crosslink composition, and self-healing capacity is a strong function of the valency and redox potential of metal ions in the precursor solution. Catechol-bearing hydrogels exhibit highly compliant mechanical properties with storage moduli ranging from = 0.1-5 kPa depending on the choice of redox active metal ions in the precursor solution. The gelation kinetics is informed by the net cell potential of redox active components in the precursor solution. Finally, redox potential of the metal ion precursor can differentially alter the effective density of crosslinks in networks and confer properties to hydrogels such as self-healing capacity. Taken together, this parametric study generates new insight to inform the design of catechol-bearing hydrogel networks formed by electrochemical-mediated multimodal crosslinking.
含儿茶酚的聚合物通过协同氧化交联和配位化学形成水凝胶网络。在这里，我们描述了由儿茶酚功能化四臂聚（乙二醇）与选择的金属阳离子组成的前体溶液的阳离子依赖性电化学介导凝胶化的动力学。凝胶化动力学、力学性能、交联组成和自修复能力强烈依赖于前体溶液中金属离子的价态和氧化还原电位。含儿茶酚的水凝胶具有高顺应性的力学性能，储能模量范围为 = 0.1-5 kPa，具体取决于前体溶液中氧化还原活性金属离子的选择。凝胶化动力学受前体溶液中氧化还原活性成分的净电池电势的影响。最后，金属离子前体的氧化还原电位可以改变网络中有效交联密度的差异，并赋予水凝胶自修复能力等特性。总的来说，这项参数研究为通过电化学介导的多模式交联形成的含儿茶酚水凝胶网络的设计提供了新的见解。
