Synthesis and characterization of a non-aqueous conductive microgel coated with poly(aniline)–DBSA in a colloidal dispersion

An electrically conductive microgel coated with poly(aniline) and dodecylbenzenesulfonic acid (PANI–DBSA) was prepared in an organic medium containing polymeric microgels and aniline–DBSA salts using ammonium persulphate (APS) as an oxidant, to yield a colloidal dispersion. Polymerization kinetics similar to those of the aqueous system were observed, with an induction period of about 80–100 mm. At a molar ratio of 1.2 of the oxidant to aniline, the maximum conductivity was obtained and the electrical conductivity reached values as high as 0.2–0.8 S/cm. The conductivity of the prepared conductive microgel increased by increasing the weight ratio of PANI–DBSA/non-aqueous conductive microgel, and leveled off at a ratio larger than 0.30. Transmission electron microscopy revealed that the prepared conductive microgel has a core-shell microsphere, which is composed of a cross-linked acrylic core and a PANI–DBSA shell. The particle size of the prepared conductive microgel is distributed in the range of 80–90 nm. Highly transparent films in the 103–105 Ω per square range could be prepared by varying the film thickness.