Responsiveness of electric resistance of polymer-grafted carbon black/alumina gel composite against solvent vapor and solute in solution

The carbon black/alumina gel composites were prepared by sol-gel reaction o f aluminum isopropoxide in the presence of polymer-grafted carbon black. Th e electric resistance of the alumina gel composite from polymer-grafted car bon black was very sensitive to vapor of good solvent for grafted polymer o n carbon black: the electric resistance of the alumina gel composite sudden ly decreased in solvent vapor and returned to initial resistance when it wa s transferred into dry air. The effect of surface area and particle size of carbon black on the responsiveness was also investigated. In addition, the electric resistance of the alumina gel composite was found to respond to w ater and methanol in n-hexane and diethyl ether.