A State-of-the-art Review on Multi-Cross-linked Hydrophobic Associated Hydrogels for Soft Electronics, Biomedical, and Environmental Applications

Abstract

Thanks to their considerable toughness, self-recoverability, high swelling degree and stimuli-responsiveness, hydrophobic association (HA) hydrogels are promising in wearable electronics, biomedical applications and water treatment industry. Multiple (physical or/and chemical) cross-links can also promote the above-mentioned properties, broadening applications of the gels. Previous reviews on the HA hydrogels focused only on their mechanical and self-healing for biomedical applications. Herein, we aim to introduce HA hydrogels having multiple crosslinks (multi-cross-linked HA (MCHA) gels), discuss their various properties, and then present their (potential) practical applications. To explain, this review first describes the synthesis of MCHA gels. Then, mechanical, rheological, self-healing, injectability, swelling properties, and stimuli-responsiveness of MCHA hydrogels are discussed. In the meantime, we suggest useful approaches to address the current challenges for the sake of improving these properties. Finally, based on properties of MCHA gels, we introduce their (potential) applications in the field of soft electronics, biomedical, environment, and superabsorbents, followed by evaluate the performance of the developed devices in some cases. Taken together, this review can provide helpful perspective in developing high-performance MCHA hydrogels.