Study On The Conductive Properties Of Bromine Doped Polyaniline And MWNTs/Br Dopped Polyaniline Composites

Conducting polymers (CPs) and their composites attract much attention because of their great potential value in application. Polyaniline (PANI) is found to be the most promising because of its ease of synthesis, low monomer cost, tunable properties, and better stability in undoped and doped states compared to other CPs, these advantages have led PANI to more potential applications in many areas such as electrical, electronics, thermoelectric, electrochemical,electromagnetic, electro-luminescence and sensors.Polyaniline was synthesised by chemical oxidation method, then doped by bromine vapor, the conductivity of PANI was increased by 11 orders of magnitude after doping. FTIR, TGA, UV-Vis and XPS spectra were used to characterize the interaction between dopants and PANI and studied the conducting mechanism of Br doped PANI. It is showed that bromine anions and charge transfer complex formed in the doping process enhanced the charge carrier concentration then promote the conductivity of PANI.MWNTs/PANI and MWNTs/Br2 doped PANI composites were prepared by mechanical blending method, exhibiting high electrical conductivity. Fourier transform infrared spectroscopy (FTIR),thermo gravimetric (TG), ultraviolet-visible absorption spectra (UV-Vis), x-ray powder diffraction(XRD) and X-ray spectroscopy (XPS) were used to study the electrical conductivity properties and mechanism. The results suggested thatπ-πand p-πsystem was formed between MWNTs and doped PANI.MWNTs combined with the Br2 doped PANI to generate charge transfer composites, then form individual conductive units, which play a critical role in the conducting net of composites.With the increase of conductive units, conducting system was formed by conductive unit connection and the conductivity of composites reaches the maximum.