Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Colloid Interface Sci. 2022 Feb 15;608(Pt 1):396-404. doi: 10.1016/j.jcis.2021.09.125. Epub 2021 Sep 24.
One prevailing method to construct excellent temperature tolerance/long-lasting moisture hydrogels is to couple the original hydrogel networks with freezing-tolerant/moisture retaining agents, including ionic liquids, inorganic salts, zwitterionic osmolytes, and polyhydric alcohols. Among them, organohydrogels have shed new light on the development of ionic skins with long-term usability and stable sensing performance at subzero temperatures due to their long-lasting water retention and anti-freezing capability.
We report a dual network organohydrogel by doping conductive ZnSO into the double network hydrogel of polyvinyl alcohol-polyacrylamide (PVA-PAM) with subsequent immersing in a mixed solvent of ethylene glycol (EG) and HO. The anti-freezing and moisture retaining abilities of the PVA/PAM/Zn/EG (PPZE) organohydrogel were studied and the sensing performances of the PPZE organohydrogel-based ionic skin were investigated.
The organohydrogel exhibits a high conductivity (0.44 S m), excellent fatigue resistance and exceptional moisture retaining ability with more than 99.3% of the initial weight retention after 31 days storage at ambient temperature. Importantly, the PPZE organohydrogel-based ionic skin shows an ultra-low temperature anti-freezing ability and remains flexibility and sensing capability with a high sensitivity (signal response time ∼ 0.23 s) even at -50 °C. The PPZE organohydrogel demonstrates a tremendous potential in artificial skin and health monitoring.
构建卓越的温度耐受性/持久保湿水凝胶的一种流行方法是将原始水凝胶网络与耐冻/保湿剂结合使用，包括离子液体、无机盐、两性离子渗透调节剂和多元醇。其中，由于其持久的保水能力和抗冻能力，有机水凝胶为具有长期可用性和在亚低温下稳定传感性能的离子皮肤的发展带来了新的曙光。
我们通过将导电 ZnSO 掺杂到聚乙烯醇-聚丙烯酰胺（PVA-PAM）的双网络水凝胶中，随后浸入乙二醇（EG）和 HO 的混合溶剂中，报告了一种双网络有机水凝胶。研究了 PVA/PAM/Zn/EG（PPZE）有机水凝胶的抗冻和保湿能力，并研究了基于 PPZE 有机水凝胶的离子皮肤的传感性能。
有机水凝胶表现出高导电性（0.44 S m）、优异的耐疲劳性和卓越的保湿能力，在环境温度下储存 31 天后，初始重量保留率超过 99.3%。重要的是，基于 PPZE 有机水凝胶的离子皮肤具有超低温抗冻能力，即使在-50°C 下仍保持灵活性和传感能力，具有高灵敏度（信号响应时间约为 0.23s）。PPZE 有机水凝胶在人造皮肤和健康监测方面具有巨大的潜力。
