YING Bangyu, LI Yang, YANG Mujie

(Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027)

Abstract: Water soluble polyaniline (PANI) with polystyrene sulfonic acid and p -toluene sulfonic acid as doping agents was synthesized by chemical oxidation polymerization, and characterized by UV-Vis spectroscopy. A resistive -type thin film humidity sensor based on the PANI was prepared by dip coating. Its impedance changed linearly on a semi -logarithmic scale from 8105 to 4103 in the range of 0～97%RH, showing high sensitivity. In addition, it exhibited a moderate hysteresis of about 4.5 %RH and a fast response (t90% of 10 s and 11 s for adsorption and desorption, respectively). It is promising as a polymer sensitive material for the preparation of high performance humidity sensor capable of detecting low humidity and realizing full range sensing.

Key words: polyaniline, humidity sensitive properties, humidity sensor