Inspired by the “brick-and-mortar” structure and remarkable mechanical performance of nacre, many efforts have been devoted to fabricating nacre-mimicking materials. Herein, a class of graphene oxide (GO) based artificial nacre material with quadruple hydrogen-bonding interactions was fabricated by functionalization of polydopamine-capped graphene oxide (PDG) with 2-ureido-4[1H]-pyrimidinone (UPy) self-complementary quadruple hydrogen-bonding units followed by supramolecular assembly process. The artificial nacre displays a strict “brick-and-mortar” structure, with PDG nanosheets as the brick and UPy units as the mortar. The resultant nanocomposite shows an excellent balance of strength and toughness. Because of the strong strengthening via quadruple hydrogen bonding, the tensile strength and toughness can reach 325.6 ± 17.8 MPa and 11.1 ± 1.3 MJ m^–3, respectively, thus exceeding natural nacre, and reaching 3.6 and 10 times that of a pure GO artificial nacre. Furthermore, after further H₂O treatment, the resulting H₂O-treated PDG-UPy actuator displays significant bending actuations when driven by heat. This work provides a pathway for the development of artificial nacre for their potential applications in energy conversion, temperature sensor, and thermo-driven actuator.

中文翻译：

---

氧化石墨烯超分子组装的人工珍珠母

受“砖混结构”结构和珍珠母出色的机械性能的启发，人们在制造类似珍珠母的材料上进行了许多努力。本文中，通过将聚多巴胺封端的氧化石墨烯（PDG）与2-ureido-4 [1 H]官能化，制备了一类具有四重氢键相互作用的基于氧化石墨烯（GO）的人造珍珠质材料。]-嘧啶酮（UPy）自互补四氢键合单元，然后进行超分子组装过程。人造珍珠质显示出严格的“砖混结构”，其中PDG纳米片为砖，UPy单元为砂浆。所得的纳米复合材料显示出优异的强度和韧性平衡。由于通过四重氢键的强力增强，抗张强度和韧性分别可以达到325.6±17.8 MPa和11.1±1.3 MJ m ^–3，从而超过天然珍珠母质，是纯GO人造珍珠母质的3.6和10倍。此外，在进一步的H ₂ O处理之后，所得的H ₂经过O处理的PDG-UPy执行器在受热驱动时显示出明显的弯曲执行力。这项工作为人造珍珠层在能量转换，温度传感器和热驱动执行器中的潜在应用提供了开发途径。