Institute of Industrial Science, The University of Tokyo , 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Department of Materials Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Biomacromolecules. 2017 Sep 11;18(9):2959-2966. doi: 10.1021/acs.biomac.7b00921. Epub 2017 Aug 30.
Man-made glues often fail to stick in wet environments because of hydration-induced softening and dissolution. The wound healing process of a tunicate inspired the synthesis of gallol-functionalized copolymers as underwater adhesive. Copolymers bearing three types of phenolic groups, namely, phenol, catechol, and gallol, were synthesized via the methoxymethyl protection/deprotection route. Surprisingly, the newly synthesized copolymers bearing gallol groups exhibited stronger adhesive performances (typically 7× stronger in water) than the widely used catechol-functionalized copolymers under all tested conditions (in air, water, seawater, or phosphate-buffered saline solution). The higher binding strength was ascribed to the tridentate-related interfacial interaction and chemical cross-linking. Moreover, gallol-functionalized copolymers adhered to all tested surfaces including plastic, glass, metal, and biological material. In seawater, the performance of gallol-functionalized copolymer even exceeds the commercially available isocyanate-based glue. The insights from this study are expected to help in the design of biomimetic materials containing gallol groups that may be utilized as potential bioadhesives and for other applications. The results from such a kind of comparable study among phenol, catechol, and gallol suggests that tridentate structure should be better than bidentate structure for bonding to the surface.
人造胶水在潮湿环境中常常失效，因为水合作用会导致其软化和溶解。基于被囊动物的伤口愈合过程，研究人员合成了含没食子酚官能团的共聚体作为水下胶粘剂。通过甲氧基甲基保护/脱保护路线，合成了含三种酚类基团（苯酚、儿茶酚和没食子酚）的共聚体。令人惊讶的是，与广泛使用的儿茶酚官能化共聚体相比，新合成的含没食子酚基团的共聚体在所有测试条件下（在空气、水、海水或磷酸盐缓冲盐溶液中）都表现出更强的粘附性能（通常在水中强 7 倍）。更高的结合强度归因于三叉相关的界面相互作用和化学交联。此外，含没食子酚的共聚体能够粘附在所有测试的表面，包括塑料、玻璃、金属和生物材料。在海水中，含没食子酚的共聚体的性能甚至超过了市售的基于异氰酸酯的胶水。这项研究的结果有望有助于设计含有没食子酚基团的仿生材料，这些材料可用作潜在的生物胶粘剂和其他应用。在苯酚、儿茶酚和没食子酚之间进行这种类似的比较研究的结果表明，对于与表面的键合，三齿结构应该优于二齿结构。
