Preparation Of Flexible Lightweight Graphene/Carbonnanotube/Silic One Rubber Composites And Their Electromagnetic Shielding Applications

With the widespread use of various electronic devices such as mobile phones and computers,problems such as electromagnetic radiation,electromagnetic pollution and information leakage have caused great troubles for people's production,life and health.As a new type of electromagnetic shielding material,conductive silicone rubber not only has good flexibility,sealing and weather resistance,but also exhibits excellent electromagnetic shielding performance,which can effectively solve the above problems.For conductive silicone rubber,the electrical conductivity of the filler and its dispersion and connectivity in the silicone rubber are important factors that limit its overall electrical conductivity and electromagnetic shielding performance.The traditional blending method can not achieve the uniform distribution and high-efficiency penetration of the filler in the matrix material,resulting in problems such as large filler content and poor electromagnetic shielding performance.Therefore,it is of great practical significance to develop a new construction strategy for the preparation of silicone rubber composites with low filler content and high shielding effectiveness.Based on the above problems,graphene oxide(GO)with good dispersibility being as the main three-dimensional material precursor and high-conductivity single-walled carbon nanotubes(SWCNT)being as the second conductive filler are used to prepare a flexible graphene/carbon nanotube/silicone rubber composite(PTGCA)by the method of pre-building graphene-based aerogel network and backfilling silicone rubber.On the one hand,the construction method promotes the uniform dispersion of pure SWCNT in an aqueous system by means of the dispersion of GO,and effectively retains its high conductivity;on the other hand,the graphene sheet skeleton and SWCNT form an efficient dual network in the matrix material,which becomes an effective transmission channel for electronics and significantly improves the utilization and connectivity of the filler.Therefore,the new PTGCA composite exhibits high electrical conductivity(1.2 S/cm),high electromagnetic shielding effectiveness(37.6 dB)and excellent mechanical properties at a low filler loading(0.24 wt%).In addition,in order to meet the more stringent new requirements of electromagnetic shielding materials in aerospace,military aircraft and other fields.A lightweight,multi-shaped silicone rubber composite material was constructed in this paper.We have prepared a series of porous lightweight PTGCA composites with adjustable porosity and density by simply controlling the backfilling the concentration of silicone rubber monomer.The electromagnetic shielding performance of The material with a porosity of 85%and a density of 0.15 g/cm~3 is achieved 37.8 dB.At the same time,taking the zigzag material as an example,the mold is customized by 3D printing technology,and the preparation of different sawtooth angle composite materials is realized.The composite exhibits excellent tensile,compressive and angular stability while exhibiting excellent electromagnetic shielding performance which is up to 37.7 dB.