Research On Humidity Sensing Properties And Film Preparation Of Vanadium Titanium Acid Doped Polyaniline

In this paper, we employed the constant potential method preparing film humiditysensitive material modified by vanadium acid, titanate acid and vanadium titanium acid. Bymeans of optical microscopy, vanadium titanium acid film-forming ability is the best. Twokinds of vanadate and vanadium titanium acid thin films in the range of11%~97%relativehumidity have a certain humidity sensitive features. However, the wet hysteresis characteristicis too large, which means that the feeling wet characteristic is further needed to improve andenhance.Thereinto, polyaniline prepared by constant potential method shows better performanceof humidity sensor. Compared with the insitu chemical oxidation method, this method has theadvantage, what the process is more simpler and easier and the application prospect ofindustrialization is better.Through the HCl, titanate acid and vanadate, vanadium titanium acid doping experiments,we doped polyaniline and studied the performance of the humidity sensitive. We discussed thedoping effect of eigenstate and polyaniline doped state to the influence of humidity sensitiveproperties. The results show that, with the electrochemical polymerization polyaniline bypotentiostatic method and in situ doping vanadium titanium acid, the resistance of polyanilinemoisture sensor in whole humidity range change hugely. There were humidity sensorresistance variation of3orders magnitude of vanadium-titanium acid doped polyaniline, thecurve was high sensitivity and good linearity. Hysteresis is about5%RH, both the responseand recovery speed are quick. As a result, the polyaniline moisture sensor with good humiditysensitive performance is new humidity sensitive materials.