Carbon Dots as Fillers Inducing Healing/Self-Healing and Anticorrosion Properties in Polymers

5 years ago

Carbon Dots as Fillers Inducing Healing/Self-Healing and Anticorrosion Properties in Polymers

Yeshayahu Lifshitz, Hao Li, Lulu Hu, Yang Liu, Hui Huang, Sijie Guo, Changan Liu, Juan Liu, Yijun Fu, Cheng Zhu, Shuit-Tong Lee, Naiyun Liu, Zhenhui Kang, Igor Bello

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. This work utilizes a novel, simple, and versatile approach to produce self-healing polymers by introduction of surface functionalized carbon dots to the polymer. The concept is successfully validated for several common bulk polymers and standard polymer coatings. The introduction of carbon dots not only induces self-healing but also significantly improves the anticorrosion resistance of the polymer coatings.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701399