In this paper, multi-walled carbon nanotubes (MWCNTs) were modified using ionic liquids (ILs), and silicone rubber/carbon nanotube composites were prepared. The surface of carbon nanotubes is coated with a layer of ionic liquid by non-covalent bond modification, and the van der Waals force between the carbon nanotubes is reduced to achieve the purpose of improving their dispersibility. The electrical conductivity of silicone rubber/carbon nanotube composites prepared by modified carbon nanotubes is improved. The dispersion of modified carbon nanotubes in silicone rubber matrix and the interface interaction between carbon nanotubes and silicone rubber are analyzed by rubber process analyzer and scanning electron microscopy (SEM) tests. The effects of modified carbon nanotubes on electrical conductivity, mechanical properties and electromagnetic shielding properties of silicone rubber composites were studied. The results show that the dispersion of carbon nanotubes in silicone rubber matrix is improved effectively through the modification of ionic liquid, the conductive property of the composite is improved, the electromagnetic wave reflection of the composite is increased, and the electromagnetic shielding efficiency of the composite is improved, and the shielding efficiency is up to 26 dB.

Keywords: ionic liquid, carbon nanotubes, silicone rubber, electromagnetic shielding.