A Self-Healing Composite Material with Microwave Absorbing and Anticorrosion Properties Accelerated by Carboxylated Carbon Nanotubes

Due to rapid self-healing characteristics, hydrogen-bonding composite materials have great potential in biological and medical fields. Carbon nanotubes have been widely used in composites and engineering fields because of their high aspect ratio and excellent mechanical, electrical, and chemical stability. Therefore, understanding how to combine carbon nanotubes with a hydrogen bond self-healing interaction can be important to expand the application field of self-healing materials. In this paper, we designed and fabricated a kind of self-healing composite material with a rapid hydrogen-bonding interaction by polymerization of polyvinylpyrrolidone (PVPON) with appropriate proportions of carboxylated multiwalled carbon nanotubes (MWCNTs-COOH) as additives. In addition, the self-healing process of the PAA-PVPON composites with different amounts of MWCNTs-COOH was simulated by molecular dynamics (MD). Our results showed that the composite materials performed excellent self-healing properties (initial self-healing time within 5 min, 75% of mechanical self-healing efficiency, and more than 100% anticorrosion self-healing efficiency), high reflection loss (<-27 dB), and high impedance modulus with only a 5 wt % MWCNTs-COOH addition. Moreover, the results of the MD calculation indicated that the MWCNTs-COOH could improve the ability of the composite materials to contact each other through the water layer, thus accelerating the self-healing speed on the basis of the increase of the density and attraction of the materials. Our work provided the experimental and theoretical basis for the application of MWCNTs-COOH in more hydrogen-bonding, self-healing composite materials.