Preparation and microwave absorption properties of Nanomesh Poly (3,4-ethylenedioxythiophene) covalently functionalized graphene oxide

In this work, we report a simple and effective method to prepare conducting poly (3,4-ethylenedioxythiophene)/thiophene-grafted graphene oxide (Th-GO-PEDOT) composite with enhanced microwave absorption properties. The first step, the carboxyl group of graphene oxide was converted into an acyl chloride intermediate by treating with thionyl chloride and then reacted with thiophene to give the thiophene group. The second step, the target product of Th-GO-PEDOT was successfully obtained by in-situ polymerization of 3,4-ethylenedioxythiophene on the surface of thiophene-grafted graphene nanosheets (Th-GO). The resulting samples were fully characterized by Raman spectroscopy, FT-IR, X-ray and Vector network analyzer. The as-prepared Th-GO-PEDOT composites exhibited superior electromagnetic microwave absorption performance and showed the minimum reflection loss (R_L) of − 47.5 dB (99.9% microwave absorption) at 15.5 GHz frequency and effective frequency (R_L ≤ − 10 dB) of 4.9 GHz only 1.5 mm matching thickness. This study found that the strong covalent bond interaction between PEDOT and graphene is the crucial factor for the enhanced EM absorption performance, which provided a method for designing and manufacturing the microwave absorption materials further to meet the requirements of the ideal absorber.