Films of polyaniline (PANI) interpolymer complexes were electrodeposited from aqueous solutions of aniline containing: (1) poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA, flexible-backbone), (2) poly-(p,p'-(2,2'-disulfoacid)-diphenylen-tere-phthalamid) (t-PASA, rigid-backbone), (3) mixtures of the former two polyacids in different ratios (6:1, 3:1, 1:1, 1:3, 1:6). The obtained polymer films were characterized by UV-vis-NIR spectroscopy, CV, spectroelectrochemical and AFM measurements. An abnormally intensive influence of the rigid-chain polyacid on the process of matrix electropolymerizalion of aniline in the presence of the polyacid mixtures was at first demonstrated. Spectroelectrochemical properties of the obtained PANI complexes with the mixtures of flexible-backbone and rigid-backbone polyacids in different ratios (up to 6:1) are very similar to those ones for the complex with rigid-backbone t-PASA. The films prepared in the presence of polyacid mixtures (up to 6:1) have high absorbance in the NIR region similarly to the complexes with rigid-backbone t-PASA. (C) 2011 Elsevier Ltd. All rights reserved.