摘要
It is still challenging for conductive polymer composite-based electromagnetic interference(EMI)shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness(EMI SE),especially undergoing external mechanical stimuli,such as scratches or large deformations.Herein,an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube(CNT)/graphene oxide(GO)/polyurethane(PU)composite with excellent and reliable EMI SE,even bearing complex mechanical condition.The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite,establishing a high EMI SE of 52.7 dB at only 10 wt%CNT/GO loading.The Diels–Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%.Additionally,the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite,resulting in high tensile strength of 43.1 MPa and elongation at break of 626%.The healing efficiency of elongation at break achieves 95%when the composite endured three cutting/healing cycles.This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.
基金
The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant Nos.51973142,51721091,21878194)
the National Key Research and Development Program of China(2018YFB0704200)
the funds of the State Key Laboratory of Solidification Processing(Northwestern Polytechnical University)(SKLSP201918).
