Morphology of polyaniline redoped by kneading with dodecylbenzene sulfonic acid

✍ Scribed by G. I. Titelman; A. Siegmann; M. Narkis; Y. Wei

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 336 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980912)69:11<2205::aid-app12>3.0.co;2-y

✦ Synopsis

Polyaniline (PANI) is often doped with an inorganic acid, which can be removed in a dedoping process with ammonium hydroxide and then replaced with an organic acid in a redoping process. This article shows that both the developing and redoping processes are influenced by the morphology of the PANI aggregates containing the primary particles. The detailed morphology develops during the aniline polymerization step and may vary from closed to open structures, depending on the polymerization conditions. The redoping process under mild conditions (manual kneading at 20-60ЊC) with dodecylbenzene sulfonic acid (DBSA) leads to the formation of a DBSA-rich surface layer covering the aggregates, which consists of fully doped PANI-DBSA and free DBSA. The thin conductive PANI-DBSA layers surrounding the aggregates form a continuous conducting network in compression-molded samples. The depth of penetration of DBSA molecules into the PANI-base aggregates obviously depends on the aggregates structure, that is, a higher DBSA penetration and, thus, a more continuous PANI-DBSA outer layer for the open structures.