Probing the Molecular Interactions at the Conducting Polyaniline Nanomaterial Surface via a Pyrene Fluorophore

Abstract

We report a unique fluorophore cumulant dopant approach for tracing the molecular interaction at the polyaniline nanomaterial surface. Emulsion polymerization of aniline + pyrene sulfonic acid (PSA) produced well-defined fluorescent polyaniline nanofibres of 250 nm diameters with lengths up to 1−3 μM. Post-polymerization doping of a polyaniline emerldine base with PSA produced fluorescent agglomerated nanospheres of 500−700 nm in diameter. Dynamic light scattering (DLS) analysis of the aniline + PSA complex confirmed the existence of ∼25 nm micellar aggregates in the emulsion which templates for the polyaniline nanofibers during the chemical oxidation process. The compositions of the dopant and polymer in the nanomaterials were determined by absorbance spectroscopy. The plots of incorporation of PSA in the nanomaterials versus feed revealed that the dopants incorporated a five times higher amount in the emulsion route compared to that of post-doping process. Wide angle X-ray diffraction (WXRD) analysis sh...