The preparation and properties of carbon nanotubes in-situ encapsulated by polyaniline

Insitu encapsulation of carbon nanotubes by polyaniline was carried out by polymerization of aniline in hydrochloric acid solution with (NH4)2S2O8 as the oxidizing agent. The structures and configurations of the encapsulated carbon nanotubes were observed by SEM and TEM. The surface properties and the microwave electromagnetic parameters of this material were tested. Results showed that when the weight ratio of carbon nanotubes to aniline was equal to 4∶1, all of the polyaniline produced could fully encapsulate the carbon nanotubes, with the thickness of the encapsulating layer being 10?nm～20?nm. The surface energy of the carbon nanotubes encapsulated by polyaniline was increased and dispersive ability of encapsulated carbon nanotubes as powder or in water was also improved significantly. The real part (e′, μ′), the imaginary part (e″, μ″) and the dissipation factor (tgδe=e″/e′, tgδm=μ″/μ′) of the microwave electromagnetic permittivity were improved. Carbon nanotubes encapsulated by polyaniline would be a good candidate for electromagnetic shielding applications.