A Humidity Sensor Using Cross‐linked Quaternized Polyvinylpyridine

Poly(4‐vinylpyridine) was simultaneously cross‐linked and quaternized with α, ω‐dichloroalkane on the surface of an alumina substrate that had a pair of gold electrodes on it. The impedance of this device varied from 107 to 103Ω for the entire humidity range. The effect of preparation conditions such as reaction time or quaternizing reagents on the electrical properties as a humidity sensor was investigated. The resistivity depends on the amount of sorbed water regardless of the degree of quaternization.