Temperature sensitivity of composite hydrogel prepared by surface graft polymer of NIPAAm and bamboo charcoal powder

摘要

This study aimed at fabricating a new type temperature sensor device by taking advantages of electrical conductivity of bamboo charcoal powder and temperature sensibility of NIPAAm hydrogel. The resistance of such a composite device will be affected by temperature. Bamboo charcoal powders were first subjected to oxygen plasma treatment. The treated bamboo charcoal powders were then UV graft polymerization with N-isopropylacrylamide (NIPAAm) monomer solution to be immobilized on the electrode which had previously been modified with plasma of tetramethyltin (TMT) and O _2 gas mixture. Using simple environment test to measure resistance, the LCST of bamboo charcoal powders mixed with NIPAAm hydrogel was found to be 31°C. At ambient temperatures higher than LCST, the electrode resistance decreases. The surface morphology of composite hydrogel was observed by SEM.