Polyaniline nanofibers and their self-assembly into a film to be used as ammonia sensor

Abstract

In this research, polyaniline (PANI) nanofibers were chemically synthesized by the hydrochloric acid (HCl) assisted interfacial polymerization method, where the morphologies and electrical properties of the nanofibers were controlled by the concentration of the HCl solution. The as-synthesized PANI nanofibers were assembled into a sensitive film with controlled thickness and nice uniformity using a liquid–gas interfacial self-assembly method. Field emission scanning electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffraction were used to characterize the PANI nanofibers. The sensing experiments were performed at room temperature with the injection of ammonia at different concentrations. All the sensors showed a good linear response to the target gas, especially for the sample of PANI doped with [HCl] = 1 mol L⁻¹, for which the reproducibility, continuity and selectivity were further tested. The results obtained in this research will be useful for potential applications in related fields of ammonia detection.