Stable polyaniline-dodecyl benzene sulfonic acid (PANI-DBSA) aqueous disper
sions were obtained by a unique method of aniline polymerization in the pre
sence of DBSA, through an anilinium-DBSA complex appearing as solid needle-
like particles, in an aqueous medium. The average size of the PANI primary
particles, determined by small angle X-ray scattering (SAXS), is 18.7 nm. T
hese primary particles form aggregates, which further cluster into similar
to 50 mu m agglomerates. PANI-DBSA/polymer blends were obtained by mixing a
n aqueous PANI-DBSA dispersion with an aqueous emulsion of the matrix polym
er, followed by water evaporation. These blends exhibit electrical conducti
vity already at a very low PANI-DBSA content (0.5 wt.%). The conductivity l
evel of the various blends depends on the PANI content, on the surfactant p
resent in the polymer matrix emulsion, and it is practically independent of
the polymer matrix nature. Thus, a similar structuring mechanism prevails
in these blends, irrespective of the polymer matrix (contrary to solution a
nd melt blends). The PANI-DBSA particles strongly segregate within the poly
mer matrix, already in the combined aqueous dispersion, and upon drying, a
very fine conductive network is formed. This strong segregation tendency le
ads to a conductive network formation already at low PANI-DBSA contents, th
us generating the conductive blends. (C) 2000 Published by Elsevier Science
S.A. All rights reserved.