Exploring graphene and graphene/nanoparticles as fillers to enhance atomic oxygen corrosion resistance of polyimide films

Graphene and graphene/nanoparticles were explored to enhance the atomic oxygen (AO) corrosion resistance of polyimide (PI) composites. Graphene flakes (EGs) were produced by electrochemical method using alternating current (AC). A series of EGs/PI composite films were prepared by in-situ polymerization. After exposure to AO, although all EGs/PI composite films were resistant to AO, we found a much greater enhancement, i.e. adding 1.5 wt% EGs can reduce the mass loss of the composite by 42%. On this basis, EGs/SiO2 and EGs/Al2O3 co-doping fillers were firstly used to further enhance the AO corrosion resistance of PI. The sample co-doped 1.5 wt% EGs with 3 wt% SiO2 could achieve a 71% decrease in the composite' mass loss. Bonding effect and barrier effect of graphene fillers are responsible for the enhanced protective performance. At the same time, the "synergistic effect" between EGs and nanoparticles also plays a role in the enhancement. These preliminary but interesting results pave a novel way for the study of AO corrosion resistance.