Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

Abstract

Currently, the enhancement in electromagnetic interference (EMI) performance of polymeric composite generally relies on either improving electrical conductivity (σ) for stronger electromagnetic (EM) reflections or tailoring structure for higher EM resonances. Herein, we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration (CPP-SS), which can reinforce these two factors simultaneously. The structural information was supplied by optical microscopy (OM) and scanning electron microscopy (SEM), both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene (UHMWPE)/graphene composites. Then, the result showed that CPP-SS can significantly improve the σ of samples. Ultimately, advanced specific EMI shielding efficiency of 31.1 dB/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%. Meanwhile, it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed. This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPP-SS, and to bring us a simple and efficient approach for fabricating high-performance, strong and light-weight polymeric EMI shields.