Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
Soft Matter. 2019 Oct 14;15(38):7654-7662. doi: 10.1039/c9sm01254k. Epub 2019 Sep 5.
In this work, a facile and simple yet effective method to generate intrinsic autonomous self-healing polymers was developed, leading to new materials that can be easily fine-tuned both mechanically and chemically. The new materials were designed to incorporate two dynamic and reversible types of chemical bonds, namely dynamic imine and metal-coordinating bonds, to enable autonomous self-healing, controlled degradability and ultra-high tunable stretchability (up to 800% strain) based on the ratio of metal to ligand incorporated. Through an easy condensation reaction, imine bonds are generated at the end-termini of a short siloxane chain. The new dynamic system was characterized by a variety of techniques, including tensile-pull strain testing, atomic force microscopy and UV-Vis spectroscopy, which showed that the highly dynamic imine bonds, combined with coordination with Fe ions, allow for the material to regenerate 88% of its mechanical strength after physical damage. The materials were also controlled to be degraded in mild acidic conditions. Lastly, application in self-healable electronics was demonstrated through the fabrication of a capacitive-based pressure sensor, which shows good sensitivity and dynamic response (∼0.33 kPa) before and after healing.
在这项工作中，开发了一种简便有效的方法来生成内在自主自修复聚合物，从而得到了新型材料，这些材料在机械和化学方面都可以很容易地进行微调。新的材料被设计成包含两种动态和可逆的化学键，即动态亚胺键和金属配位键，以实现自主自修复、可控降解和超高的可拉伸性（高达 800%的应变），这取决于所加入的金属与配体的比例。通过简单的缩合反应，亚胺键在短硅氧烷链的末端生成。新的动态系统通过各种技术进行了表征，包括拉伸拉伸应变测试、原子力显微镜和紫外可见光谱，结果表明，高度动态的亚胺键与 Fe 离子的配位相结合，使得材料在物理损伤后能够再生其 88%的机械强度。这些材料也可以在温和的酸性条件下进行控制降解。最后，通过制造基于电容的压力传感器，展示了自修复电子学的应用，该传感器在修复前后表现出良好的灵敏度和动态响应（约 0.33 kPa）。
