Synthesis, Electrical Conductivity, and Wave-Absorption Performances of Bamboo-Based Composites Co-Doped with Graphene Oxide and Polyaniline

Bamboo was carbonized and further modified via co-doping with graphene oxide (GO) and polyaniline (PANI) to prepare microwave absorption composites (GO/PANI/CB) by in situ polymerization of 1R-(-)-Camphorsulfonic acid (L-CSA). The conductivity of GO/PANI/CB reached 2.17 ± 0.05 S/cm under the optimized process conditions. The oxygen-containing group of GO reacts with PANI to form hydrogen bonds and thus polymerize. The GO and PANI particles covered the carbonized bamboo (CB) surface in a disordered aggregation form. Based on the measuring method of the vector network analyzer (VNA), the microwave-absorption performance of GO/PANI/CB was investigated. With 30% addition of GO/PANI/CB, the minimum reflection loss (RL_min) at 7.12 GHz with a thickness of 3.5 mm of samples reached -49.83 dB. The effective absorption bandwidth (<-10 dB) is as high as 4.72 GHz with a frequency range of 11.68-16.40 GHz and a thickness of 2 mm. Compared with many PANI based electromagnetic wave absorbing materials reported in recent years, GO/PANI/CB provides improved microwave-absorption performance while maintaining high absorption bandwidth. GO/PANI/CB exhibited the advantages of simple preparation, low cost, renewability, light texture, thinness, wide absorption bandwidth, and strong absorption ability, and can be used for new microwave absorption materials.