Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, China.
Department of Materials Science and Engineering Technion, Israel Institute of Technology, Haifa, 3200003, Israel.
Adv Mater. 2017 Aug;29(32). doi: 10.1002/adma.201701399. Epub 2017 Jun 22.
Self-healing is the way by which nature repairs damage and prolongs the life of bio entities. A variety of practical applications require self-healing materials in general and self-healing polymers in particular. Different (complex) methods provide the rebonding of broken bonds, suppressing crack, or local damage propagation. Here, a simple, versatile, and cost-effective methodology is reported for initiating healing in bulk polymers and self-healing and anticorrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nanocrystallites, into the polymer matrix forming a composite. The CDs are blended into polymethacrylate, polyurethane, and other common polymers. The healing/self-healing process is initiated by interfacial bonding (covalent, hydrogen, and van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional groups which terminate the CDs. The healing properties of the bulk polymer-CD composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that are healed and by following the self-healing of scratches intentionally introduced to polymer-CD composite coatings. The composite coatings not only possess self-healing properties but also have superior anticorrosion properties compared to those of the pure polymer coatings.
自修复是大自然修复损伤和延长生物实体寿命的方式。各种实际应用一般都需要自修复材料，特别是自修复聚合物。不同的（复杂）方法提供了重新键合断裂键、抑制裂纹或局部损伤扩展的方法。在这里，报道了一种简单、通用且具有成本效益的方法，用于在块状聚合物中引发修复以及在聚合物涂层中实现自修复和防腐性能：将碳点（CDs），即 5nm 大小的碳纳米晶，引入聚合物基质中形成复合材料。CDs 被混合到聚甲基丙烯酸酯、聚氨酯和其他常见聚合物中。修复/自修复过程是通过 CDs 与聚合物基质之间的界面键合（共价键、氢键和范德华键合）引发的，可以通过修饰终止 CDs 的官能团来优化。通过比较原始（块状和涂层）复合材料与经过修复的断裂复合材料的拉伸强度，以及通过跟踪有意引入到聚合物-CD 复合涂层中的划痕的自修复，评估块状聚合物-CD 复合材料的修复性能。与纯聚合物涂层相比，复合涂层不仅具有自修复性能，而且还具有优异的防腐性能。
