Humidity-sensing properties of conducting polypyrrole-silver nanocomposites

We report here the humidity-sensing characteristics of conducting polypyrrole (PPY)-silver nanocomposites prepared by wet-chemical technique. Addition of silver into the conducting polymer network shows remarkable change in resistance with relative humidity (RH). The resistance of PPY-silver nanocomposites is found to increase with RH till a threshold value, above which the resistance tends to decrease. The threshold RH value is significantly reduced with the increase in silver concentration into the conducting polymer network. The modified metal–polymer interface and the associated interfacial water molecules play the critical role in determining the electrical transport and hence the humidity-response characteristics of the nanocomposites.