Theoretical study on polyaniline gas sensors: Examinations of response mechanism for alcohol

Geometry optimization was conducted on a series of emeraldine salt (ES) oligoanilines (2x + 2)-ES+ (x = 0, 1, 2, 3), alcohols and complexes composed of oligoanilines and alcohols by density functional theory (DFT) method at UB3LYP/6-31g (d) level. Electronic properties of complexes composed by (2x + 2)-ES+ oligoanilines with methanol, ethanol, propanol and isopropanol were investigated at higher level UB3LYP/6-311++g (d, p) to model the response of polyaniline (PANI) to alcohols. Influences of oligoaniline chain length and alcohols on the binding properties of the complexes were discussed based on the calculated results.