Synergistically optimizing interlaminar and electromagnetic interference shielding behavior of carbon fiber composite based on interfacial reinforcement

The development of structure-function integrated materials is an important trend in military field. How to achieve the enhanced interfacial property and electromagnetic interference (EMI) shielding property of carbon fiber (CF) reinforced polymer (CFRP) simultaneously is the main challenge at present. Herein, the mechanically strengthened CFRP with superior EMI shielding property was developed by the introduction of reduced graphene oxide/Fe3O4, i.e., RGF into epoxy resin, combined with CF modified by uniform polyaniline (PANI) shell. The interlaminar shear analysis indicated that the RGF nanofiller in resin matrix and uniform PANI shell on CF could effectively optimize the interlaminar shear behavior due to the enhanced cohesive strength and adhesion strength among interface phase. Notably, the resultant composite achieved an interlaminar shear strength of 80.4 MPa, 37.4% higher than that of virgin CF/epoxy composite. Additionally, thanks to the excellent electromagnetic wave loss of RGF as well as the unique alternating multilayer, the super EMI shielding effectiveness of 78.5 dB with was achieved when the RGF content was 4.0 wt%, much higher than 34.7 dB of virgin CF/epoxy composite. The excellent interlaminar shear and EMI shielding behaviors endow the composite with potential application in military field, which providing a new strategy for the development of high-performance CF/epoxy composite.