Coatings Comprised of Graphene Oxide Decorated with Helical Polypyrrole Nanofibers for Microwave Absorption and Corrosion Protection

In recent years, microwave absorbing (MA) materials have developed rapidly and made good progress. However, MA materials with thin thickness and light weight are still a huge challenge. Furthermore, the application of single-function MA materials is severely restricted due to poor environmental adaptability in actual use, especially in harsh marine environments. Herein, we prepared graphene oxide/chiral polypyrrole hybrid (GO/CPPy) materials, which showed microwave absorbing properties combined with anticorrosion performance, by in situ polymerization. The sheet-layer GO/CPPy was composed of chiral helical polypyrrole and two-dimensional GO sheets. The introduction of chiral polypyrrole not only brought good dielectric loss but also produced additional magnetic loss. As a result, the GO/CPPy hybrids indicated a strong reflection loss (RL) of -55.5 dB at 8.55 GHz with a thickness of 3.8 mm. Meanwhile, they exhibited a broad effective bandwidth of 8.4 GHz from 9.1 to 17.5 GHz. In addition, 0.6% GO/CPPy-EP composite coatings displayed excellent long-term corrosion resistance with a remarkable corrosion protection capability (99.73%) after 21 days of immersion in a corrosive medium. Furthermore, the corresponding 6% GO/CPPy-EP microwave absorbing coatings retained high MA performance with a minimum RL of -27.5 dB at 12.38 GHz, which was tested using a bow reflectivity test system after immersion in 3.5% NaCl solution for 21 days. Moreover, the MA performance dropped only by 13.79%. This work could open new avenues toward the development of MA materials with corrosion protection performance.