Reversed micelle polymerization: a new route for the synthesis of DBSA-polyaniline nanoparticles

Chemical oxidative polymerization of aniline (An) was performed in dodecybenzenesulfonic acid (DBSA)-(2,2,4-trimethylpentane)-(isooctane)-water (H2O) reversed micelle system. By using a suitable functionalized protonic acid-DBSA to protonate polyaniline (PANI), the counter ion can induce processibility of the resulting PANI complex. DBSA was used to play both the roles of surfactant and dopant. The method of preparation DBSA doped PANI (DBSA-PANI) nanoparticles in reversed micelle had never been reported before. By using this method, a kind of white deposition-the DBSA-aniline salt precipitate can be avoided which availed the formation of nanoscaled particles with a dimensional uniformity. The resulting DBSA-PANI synthesized in this system and the corresponding de-doped emeraldine base (EB-PANI) were comprehensive charactered by UV-vis, FT-IR, CV, XRD, TGA-DTA, TEM, etc. The conductivity, solubility and molecular weight of the product were also investigated. By using these measurements, we have found the optimum synthetic condition. It was also found that PANI was well doped by DBSA, and the product showed a series of preferable properties. The particles of DBSA-PANI synthesized in reversed micelle were nanoscaled, needle-like in shape and had a uniform dispersal.