Cheng Ruidong, Zhang Xuehui, Li Jie, Zheng Hua, Zhang Qiuyu
Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
ACS Appl Mater Interfaces. 2024 Aug 14;16(32):42783-42793. doi: 10.1021/acsami.4c10382. Epub 2024 Aug 1.
Most natural supporting tissues possess both exceptional mechanical strength, a significant amount of water, and the anisotropic structure, as well as nanoscale assembly. These properties are essential for biological processes, but have been challenging to emulate in synthetic materials. In an effort to achieve simultaneous improvement of these trade-off features, a hydrogen bonding-induced self-assembly strategy was introduced to create nanoporous plastic-like polymer hydrogels. Multiple hydrogen bonding-mediated networks and nanoporous orientation structures endow transparent hydrogels with remarkable mechanical robustness. They exhibit Young's modulus of up to 223.7 MPa and a breaking strength of up to 10.3 MPa, which are superior to those of most common polymer hydrogels. The uniform porous nanostructures of hydrogen-bonded hydrogels contribute to a significantly larger specific surface area compared to conventional hydrogels. This allows for the retention of high mechanical properties in environments with a high water content of 70 wt %. A rubbery stage is observed during the heating process, which can reverse and reshape the manufacture of objects with various desired 2D or 3D shapes using techniques such as origami and kirigami. Finally, as a proof-of-concept, the outstanding mechanical properties of poly(MAA--AA--NVCL) hydrogel, combined with its high water content, make it suitable for applications such as smart temperature monitors, multilevel information anticounterfeiting, and artificial muscles.
大多数天然支撑组织都具有出色的机械强度、大量的水分、各向异性结构以及纳米级组装。这些特性对于生物过程至关重要，但在合成材料中模拟却具有挑战性。为了同时改善这些相互矛盾的特性，引入了一种氢键诱导的自组装策略来制备纳米多孔塑料状聚合物水凝胶。多个氢键介导的网络和纳米多孔取向结构赋予透明水凝胶显著的机械稳健性。它们表现出高达223.7 MPa的杨氏模量和高达10.3 MPa的断裂强度，优于大多数常见的聚合物水凝胶。与传统水凝胶相比，氢键水凝胶均匀的多孔纳米结构导致其具有显著更大的比表面积。这使得在水含量高达70 wt%的环境中仍能保持高机械性能。在加热过程中观察到一个橡胶态阶段，利用折纸和剪纸等技术可以对具有各种所需二维或三维形状的物体进行可逆的制造和重塑。最后，作为概念验证，聚（MAA-AA-NVCL）水凝胶出色的机械性能及其高含水量使其适用于智能温度监测器、多级信息防伪和人造肌肉等应用。
