Preparation of polyaniline conductive composites with diene-rubber or polyphenylacetylene

We describe the preparation of polyaniline (PANI-EB) by aniline oxidation w ith KIO3 and the purification of the resulting dedoped polymer by an aceton e extraction step to eliminate undesired by-products from polyaniline, whic h could generate some safety concerns in the application and use of PANI. E xcellent homogeneous and electrically conducting composite films can be pre pared from chloroform solutions of purified PANI doped with camphorsulfonic acid in presence of cis-1,4-polybutadiene as the film-forming agent. These films have been characterized by FT-IR and UV-VIS-NIX spectroscopy. A meth od to synthesisze PANI directly doped with dodecylbenzenesulfonic acid (DBS A) is also reported. DBSA-doped-PANI was then used to prepare composites wi th polyphenylacetylene (PPA) by growing homogeneous films from chloroform s olution. These films were conductive and were studied by FT-IR and UV-VIS-N IX spectroscopy. In view of the application of these composites as gas sens ors or in "electronic noses", a short discussion is presented about the cri teria used in the selection of the chemical nature of the host polymer wher e doped PANI is included to confer electrical conductivity. The interaction between the molecules to be detected and the polymeric sensing surface is discussed in terms of physisorption, chemisorption and charge-transfer-comp lex formation. Copyright (C) 2001 John Wiley & Sons, Ltd.