The relationship of conductivity to the morphology and crystallinity of polyaniline controlled by water content via reverse microemulsion

Abstract

Conducting polyaniline (PANI) with the controllable morphology and crystallinity were successfully synthesized with different water content ($W_{0} = {{\left[ {{\text{H}}_{2} {\text{O}}} \right]}} \mathord{\left/ {\vphantom {{{\left[ {{\text{H}}_{2} {\text{O}}} \right]}} {{\left[ {{\text{AOT}}} \right]}}}} \right. \kern-\nulldelimiterspace} {{\left[ {{\text{AOT}}} \right]}}$) in the reverse microemulsion stabilized with sodium bis(2-ethylhexyl)-sulfosuccinate (AOT). In the microemulsion, the systems containing the different amounts of water will show the different phase behaviors and structures. The influence of water content on morphology and crystallinity of conducting PANI was characterized by a number of techniques such as Fourier transform infrared spectra, UV–Visible, scanning electron microscopy, transmission electron microscopy, and X-ray powder diffraction and conductivity. In particular, we focus on the understanding of the relationship between the morphology and the crystallinity and the conductivity of PANI powder. With the increasing of the water content (W ₀ = 13.9, 27.8, 55.5, and 111.1) in the microemulsion system, the morphology and the crystallinity obviously changed and the values of relative conductivity are 0.05, 0.11, 2.7, and 1.8 S/cm, respectively.