The present invention concerns the use of sulphonic and phosphonic acids, functionalised with plastisizers, as dopants for polyaniline conductor films and polyaniline-based conductive composite materials. These acids meet the following formula: [chemical expression included] in which: R1 represents —SO3H or PO3H2 R2 is a linear or branched alkyl group and m equals 1 or 2, or R2 is a group having the formula: [chemical expression included] in which R1 is such as defined above and n is a whole number ranging from 1 to 16, and m equals 1.