The intriguing reversible underwater adhesive phenomena in nature have inspired the rapid development of artificial adhesives by microscopic topography engineering or chemical modification on solid surfaces. However, most of the existing reversible underwater adhesives often suffer from low adhesion strength or complex fabrication processes. Here we present a reversible underwater glue by incorporating photo- and thermal-responsive anthracenyl moieties into an adhesive polyethylenimine backbone, featuring strong, widely tunable adhesion strength from 50.5 ± 7.4 to 606.7 ± 30.3 kPa, desirable fluidity, and compatibility to various substrates. Under orthogonal photo- and thermal stimuli, the reversible anthracene dimerization endows dynamic forming and breaking of cross-linked polymer networks within the glue, leading to reversible adhesion between solid substrates. Moreover, the glue can spontaneously spread over solid surfaces and absorb interfacial water molecules to realize adequate contact, promoting strong adhesion to diverse substrates and liquid environments. This study will provide an important strategy to develop the next generation of smart underwater adhesives.

中文翻译：

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基于光敏和热敏动态共价键的可逆水下胶†

自然界中令人着迷的可逆水下胶粘剂现象通过微观形貌工程学或化学修饰固体表面激发了人造胶粘剂的快速发展。然而，大多数现有的可逆水下粘合剂经常遭受低粘合强度或复杂的制造过程的困扰。在这里，我们通过将光响应和热响应性蒽基基团结合到粘合剂聚乙烯亚胺主链中，提出了一种可逆的水下胶，该粘合剂具有从50.5±7.4到606.7±30.3 kPa的牢固，广泛可调的粘合强度，理想的流动性以及与各种基材的相容性。在正交的光和热刺激下，可逆的蒽二聚化可动态形成和破坏胶中交联的聚合物网络，导致固体基材之间的可逆粘合。此外，胶水可以自发地散布在固体表面上并吸收界面水分子以实现充分的接触，从而促进对各种基材和液体环境的牢固粘合。这项研究将为开发下一代智能水下胶粘剂提供重要策略。