A study of the electromagnetic shielding properties of epoxy resin matrix composites synergistically reinforced with CNTs and Copper foams

Copper foam (Cu f ) is regarded as a lightweight material for electromagnetic interference (EMI) shielding; nevertheless, Cu f suffers from disadvantages such as facile surface oxidation and low structural strength, preventing it from meeting aerospace service performance requirements. Hence, carboxylation-treated nanotubes (C-CNTs) incorporated into epoxy (EP) reinforced by Cu f were fabricated; and concurrently, EP reinforced by CNTs reinforced Cu f (CNTs/Cu f ) were also prepared as comparative samples. The microscopic morphology and EMI shielding performance of the above-prepared composites were characterized and tested. The results reveal that the introduction of Cu f into EP can prominently enhance the EMI shielding effectiveness of the composites; meanwhile, the concentration of C-CNTs is positively correlated with its EMI shielding. This study explores the influence of CNTs content in Cu f on the EMI effectiveness of (CNTs/Cu f ) reinforced EP materials. The experimental results indicate that the EMI shielding effectiveness reaches 42.26 dB when the content of CNTs in the matrix amounts to 0.073 wt%. And the EMI shielding effectiveness of the composites attains the maximum value of 45.53 dB when the porosity of Cu f is 130 PPI and the content of C-CNTs is 1.0 wt%. (Note: PPI refers to the average number of holes per square inch of length. The larger the number of PPI, the smaller the holes on Cu f .)