Yamada Shunsuke, Honda Takashi
Department of Electrical and Electronic Engineering, Kyushu Institute of Technology, 1-1 Sensuicho, Tobataku, Kitakyushushu, Fukuoka 804-8550, Japan.
Nanoscale. 2025 Jan 23;17(4):2184-2192. doi: 10.1039/d4nr04792c.
Gels are promising candidates for environmental sensing and implants because of their high stretchability, ionic conductivity, and low toxicity toward the environment and human body. Self-healing gels can recover their mechanical and electrical properties after rupturing under environments with harsh mechanical stress. However, current self-healing gels rely on healing agents, metal ions, or dynamic bonding; these materials exhibit toxicity and nonbiodegradability, hindering their use in environmental sensing and implant applications. Herein, we developed supramolecular ionic gels (SIGs) with self-healing capability and biodegradability through the physical crosslinking of poly(vinyl alcohol) (PVA) and the bioderived ionic liquid (IL) choline lactate. Fourier-transform infrared spectroscopy and wide-angle X-ray scattering revealed that the IL and PVA formed hydrogen bonds, thereby resulting in nanocrystalline structures in the SIGs. After cutting, dynamic bonding helps self-healed SIGs recover fracture stress and strain by 39% and 45%, respectively, compared to pristine SIGs. Furthermore, hydrogen bonding is a reversible reaction that enables ruptured SIGs to reconfigure their shapes after tensile-stress tests. The reconfigured SIGs involve fracture stress and strain comparable with those of the initial SIGs. This study provides insights into bio/ecoresorbable electronics with high mechanical robustness, which can help develop transient devices for wearables, implants, and environmental sensing.
由于具有高拉伸性、离子导电性以及对环境和人体的低毒性，凝胶是环境传感和植入物的理想候选材料。自愈合凝胶在承受苛刻机械应力的环境中破裂后，能够恢复其机械和电学性能。然而，目前的自愈合凝胶依赖于愈合剂、金属离子或动态键合；这些材料具有毒性且不可生物降解，阻碍了它们在环境传感和植入应用中的使用。在此，我们通过聚乙烯醇（PVA）与生物衍生离子液体（IL）乳酸胆碱的物理交联，开发了具有自愈合能力和生物可降解性的超分子离子凝胶（SIGs）。傅里叶变换红外光谱和广角X射线散射表明，离子液体和聚乙烯醇形成了氢键，从而在超分子离子凝胶中产生了纳米晶体结构。切割后，与原始超分子离子凝胶相比，动态键合帮助自愈合超分子离子凝胶分别恢复39%和45%的断裂应力和应变。此外，氢键是一种可逆反应，使破裂的超分子离子凝胶在拉伸应力测试后能够重新配置其形状。重新配置的超分子离子凝胶的断裂应力和应变与初始超分子离子凝胶相当。这项研究为具有高机械强度的生物/生态可吸收电子器件提供了见解，有助于开发用于可穿戴设备、植入物和环境传感的瞬态器件。
