Fabrication and characterization of polyaniline-based gas sensor by ultra-thin film technology

Abstract

Pure polyaniline (PAN) film, polyaniline and acetic acid (AA) mixed film, as well as PAN and polystyrenesulfonic acid (PSSA) composite film with various number of layers were prepared by Langmuir-Blodgett (LB) and self-assembly (SA) techniques. These ultra-thin films were characterized by ultraviolet-visible (UV-VIS) spectroscopy and ellipsometry. It is found that the thickness of PAN-based ultra-thin films increases linearly with the increase of the number of film layers. The gas-sensitivity of these ultra-thin films with various layers to NO2 was studied. It is found that pure polyaniline films prepared by LB technique had good sensitivity to NO2, while SA films exhibited faster recovery p..