A novel soluble polyaniline powder, polyaniline-maleicacid-dodecylhydrogensulfate salt was synthesized directly via emulsion polymerization pathway using benzoyl peroxide oxidant, sodium dodecyl sulfate surfactant and maleic acid as effective dopant. Dry polyaniline powder is soluble in polar solvents like DMF, NMP, DMSO and maximum solubility was found to be 6% w/v. In this emulsion polymerization pathway, both acid group (maleic acid - 0.21 U per aniline group) and surfactant molecule (dodecylhydrogensulfate - 0.25 U per aniline group) were incorporated as dopant in the polyaniline chain. Long and nonpolar chain dopant present in the polyaniline chain may provide space for the polyaniline backbone and allows the penetration of solvent molecules inside the chain and induces solubility of polymer in polar solvents. Polyaniline salt showed nano sphere morphology with average diameter of 200 nm size. The influence of synthetic conditions such as the duration of the reaction, concentration of the reactants and solvent medium on the properties of polyaniline was investigated to determine the optimum conditions for the synthesis of polyaniline salt. The conductivity of polyaniline salt was found to be 10(-1) S/cm. (c) 2006 Elsevier B.V. All rights reserved.