Morphology Tuning of Conducting Polyaniline via Static, Liquid-Liquid Interfacial Polymerization Process and its Application for Optical pH Sensing

Abstract

Abstract Nanorods/nanofibers of conducting polymer, polyaniline (PANI) were synthesized via static, liquid-liquid interfacial polymerization process using ammonium persulphate as an oxidizing agent. The monomer, aniline was dissolved in chloroform comprising the organic phase, while the oxidizing agent, ammonium per sulphate was dissolved in doubly distilled water to form an aqueous phase. Para toluene sulphonic acid (p-TSA) was used as dopant during the polymerization process to dope the polyaniline. The presence of conducting emeraldine salt phase of the polymer was confirmed by UV-Vis. and FT-IR spectroscopic characterization. This was further supported by XRD analysis. The morphological studies are carried out using FE-SEM analysis and revealed the presence of uniform sized nanorods/nanofibers having diameter of ∼90 nm and length up to few microns. This rapid and novel interfacial polymerization process shows the potential of large scale synthesis of uniform sized nanorods/nanofibers of polyaniline. The synthesized nanostructured polyaniline was successfully utilized for the optical pH sensing application in aqueous state.