Preparation and Characterization of Polyaniline– Polypyrrole Composite from Polyaniline Dispersions Shuangxi Xing, 1,2 Chun Zhao, 1,2 Tieli Zhou, 2 Shengyu Jing, 2 Zichen Wang 1 1 College of Chemistry, Jilin University, Changchun 130012, People’s Republic of China 2 State Key Laboratory on Integrated Optoelectronics, Jilin University, Changchun 130012, People’s Republic of China Received 12 January 2006; accepted 10 October 2006 DOI 10.1002/app.25667 Published online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: Polyaniline–polypyrrole (PANI-PPy) com- posite was prepared by in situ polymerization of pyrrole in PANI dispersion using FeCl 3 6H 2 O as oxidant and sodium dodecyl benzene sulfonate (SDBS) as surfactant. Different synthesis conditions of PANI dispersion includ- ing the relative concentration of aniline and SDBS and the amount of acid (HCl) on the morphology and conductivity of the resulting composites were investigated. Fourier transformation infrared (FTIR) spectra, X-ray photoelec- tron spectroscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) patterns, and contact angles of the composites showed there existed cer- tain interaction between PANI (or PANI-SDBS) and PPy. Ó 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3523– 3529, 2007 Key words: PANI-PPy composite; PANI dispersion; SDBS INTRODUCTION In recent years, conducting polymers have been extensively researched due to their interesting chem- ical and physical properties and hence their wide range of applications, including rechargeable bat- teries, gas sensors, and kinds of electronic devices. 1–3 Among these conducting polymers, polyaniline (PANI) and polypyrrole (PPy) were considered as two of the most promising materials for potential use because of their relatively high conductivity, easy preparation, and environment stability, etc. 4 Many researchers have reported their studies on the synthesis of PANI and PPy, which showed different morphology with nano- or microstructure, improv- ing characteristic in conductivity, solubility, thermal stability, and so on. 5–7 PANI or PPy compounded with different materials including inorganic nano- particles and polymers have been largely prepared because the resulting composites embodied the mer- its of the different components, which can widen the application fields than the neat ones. 8–13 However, there is very little literature on the formation of PANI-PPy composite though they both have excel- lent performances mentioned earlier. Up to now, electrochemical copolymerization of pyrrole and ani- line or electrochemical deposition of PANI and PPy layers on different substrates has been reported to obtain PANI-PPy composite. 14–18 On the other hand, PANI dispersion as an effective way for application has been prepared via the aid of kinds of steric stabilizers or surfactants. 19–23 Various PANI/poly- mer blends have been prepared using PANI disper- sions as media. 12,24 For example, PANI/polystyrene and PANI/poly(methyl methacrylate) blends were obtained by simple mixing of the aqueous PANI-do- decyl benzene sulfonic acid (DBSA) dispersion with an aqueous emulsion of the polymers. 12 Neverthe- less, polymerization of different monomers occurring in PANI dispersions seems to be a blank field in the application of PANI dispersions to the best of our knowledge. We have successfully prepared PANI dispersions using sodium dodecyl benzene sulfonate (SDBS) both as dopant and surfactant with proper acid and aniline concentration and the dispersions showed excellent stability without precipitation for at least 1 year. 25 In this article, we tried to prepare PANI-PPy composite from these dispersions and we found there existed certain interaction between PANI and PPy, which could be confirmed by their morphology, conductivity, X-ray photoelectron spec- troscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and contact angle measure- ment. The different preparation conditions and even the storing time of the dispersions would have all significant influence on the properties of the result- ing composites. Correspondence to: C. Zhao (zchun@jlu.edu.cn) or Z. Wang (wangzc@mail.jlu.edu.cn). Contract grant sponsor: National Natural Science Foun- dation of China; contract grant number: 20320120169. Journal of Applied Polymer Science, Vol. 104, 3523–3529 (2007) V V C 2007 Wiley Periodicals, Inc.