McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA.
Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA.
J Biomed Mater Res A. 2025 Jan;113(1):e37840. doi: 10.1002/jbm.a.37840.
Conductive hydrogels have gained interest in biomedical applications and soft electronics. To tackle the challenge of ionic hydrogels falling short of desired mechanical properties in previous studies, our investigation aimed to understand the pivotal structural factors that impact the conductivity and mechanical behavior of polyethylene glycol (PEG)-based hydrogels with ionic conductivity. Polyether urethane diacrylamide (PEUDAm), a functionalized long-chain macromer based on PEG, was used to synthesize hydrogels with ionic conductivity conferred by incorporating ions into the liquid phase of the hydrogel. The impact of salt concentration, water content, temperature, and gel formation on both mechanical properties and conductivity was characterized to establish parameters for tuning hydrogel properties. To further expand the range of conductivity available in these ionic hydrogels, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was incorporated as a single copolymer network or double network configuration. As expected, conductivity in these ionic gels was primarily driven by ion diffusivity and charge density, which were dependent on hydrogel network formation and swelling. Copolymer network structure had minimal effect on the conductivity, which was primarily driven by counter-ion equilibrium; however, the mechanical properties and equilibrium swelling were strongly dependent on network structure. The structure-property relationships elucidated here enable the rationale design of this new double network hydrogel to achieve target properties for a broad range of biomedical applications.
导电水凝胶在生物医学应用和软电子领域引起了广泛关注。为了解决以往研究中离子水凝胶力学性能不理想的问题，我们的研究旨在探讨影响基于聚乙二醇（PEG）的具有离子导电性的水凝胶导电性和力学性能的关键结构因素。聚醚型氨酯二丙烯酰胺（PEUDAm）是一种基于 PEG 的功能化长链大分子单体，通过在水凝胶的液相中引入离子来合成具有离子导电性的水凝胶。我们对盐浓度、含水量、温度和凝胶形成对机械性能和导电性的影响进行了表征，以确定调整水凝胶性能的参数。为了进一步扩大这些离子水凝胶的可用导电性范围，我们将 2-丙烯酰胺基-2-甲基-1-丙磺酸（AMPS）作为单共聚物网络或双网络结构引入。正如预期的那样，这些离子凝胶中的导电性主要取决于离子扩散率和电荷密度，而这又取决于水凝胶网络的形成和溶胀。共聚物网络结构对导电性的影响很小，导电性主要由抗衡离子平衡驱动；然而，机械性能和平衡溶胀强烈依赖于网络结构。本文阐明的结构-性能关系可用于合理设计这种新型双网络水凝胶，以实现广泛生物医学应用的目标性能。
