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Electrically conducting polymers are one of the promising alternative materials for technological applications in many interdisciplinary areas, including chemistry, material sciences, and engineering. This experiment was designed for providing undergraduate students with a quick and practical approach for preparation of a polyaniline-conducting polymer, demonstrating its application as a conductive coating for fabrication of smart, flexible, conductive textiles. Polyaniline was prepared by chemical oxidative polymerization (COP) of aniline monomer using ammonium persulfate as redox initiator. The polymerization was characterized by color change during the slow induction period, followed by sudden heat release during the polymerization stage due to the autoacceleration nature of this exothermic reaction. This polymerization system was used to demonstrate the heterogeneous precipitation polymerization technique. As a demonstration for the practical application of polyaniline in the area of smart conductive textiles, different nonconductive textile samples were coated with polyaniline by in situ COP and used as electronic textiles for operation of capacitive touch-screen displays.

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The zwitterionic monomer, ethyl 3-(N,N-diallylammonio)propanephosphonate, was cyclopolymerized in aqueous solutions using t-butylhydroperoxide or ammonium persulfate as initiators to afford a polyphosphonobetaine (PPB). The protonation of P(¼ ¼O)OEtOand deprotonation of ANH þ groups in PPB by HCl and NaOH, gave the corresponding cationic polyphosphononic acid (CPP) and anionic polyphosphonate (APP). The presence of two pH-responsive functionalities in APP has led to establish the equilibria: APP … PPB … CPP, the position of which very much dictates the viscosity behavior of its aqueous solution. The PPB demonstrated ''antipolyelectrolyte'' viscosity behavior; however, in contrast to many polycarbo-and polysulfo-betaines, it was found to be soluble in salt-free water as well as in salt-added solutions. Basicity constant (K 1 ) of the amine group in APP, as determined by potentiometric technique, were found to be ''apparent,'' and as such followed the modified Henderson-Hasselbalch equation. The study demonstrated a correlation between the basicity constants and viscosity values. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5693-5703, 2010

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