No abstract

Low molecular weight polyaniline nanotubes were prepared by fast emulsion polymerization in the presence of both n‐dodecylbenzenesulfonic acid (DBSA) and HCl(aq). The anilinium monomers associated with DBSA emulsifiers were found to self‐arrange into strands of associated cylindrical micelles before polymerization, as monitored by their optical activity and optical image. In the presence of some HCl(aq), the monomer‐associated cylindrical micelles expanded and the polymerization rate could be speeded up. It was found that the low molecular weight (viscosity‐averaged molecular weight) polyaniline obtained can easily lead to the formation of highly conductive, one‐dimensional nanotubes or nanofibers monitored by the variation of optical activities and λmax of the UV–visible–near IR spectra during polymerization. The DBSA/HCl ratio played an important role in the eventual properties and morphologies of the one‐dimensional polyanilines, which can be illustrated by conductivity, SEM and transmission electron microscopy measurements. The resultant one‐dimensional polyaniline nanotubes can be arranged into a layered structure by orientation, illustrated by AFM and wide‐angle X‐ray diffraction. © 2012 Society of Chemical Industry

A multiwalled carbon nanotubes (MWCNTs) were carboxylated after refluxing with sulfuric and nitric acids. These attached carboxylic acid groups were further condensated with o-phenylene diamine into amide catalyzed by dicyclohexyl carbodiimide (DCC). The obtained amidized MWCNTs were in situ-polymerized with aniline monomers to graft a conducting polyaniline (PANI) onto MWCNT (ES-g-MWCNTs) through the polymerization occurring in the ortho-and meta-positions. The reduced conductivity of the MWCNT after carboxylation can be recovered after grafting with PANI, which owns a strong k max at the near infrared region due to the extended conjugation from MWCNTs to PANI. Transmission electronic microscopic pictures show a gradual broadening of the MWCNT diameter after carboxylation, amidization, and polymerization. The weight loss from the thermogravimetric thermograms due to the carboxylations of MWCNTs, amidized MWCNTs, and the PANI grafted MWCNTs into CO 2 can be used to estimate the degree of carboxylation, amidization, and grafting of PANI. The degree of carboxylation of MWCNT calculated from ESCA spectrum is around 23% close to that estimated from TGA thermogram. The doping level of redoped PANI-grafted MWCNT is found to be 27.78% much less than the maximum 50% of neat PANI.