Grafting of polyethylene by γ-radiation grafting onto conductive carbon black and application as novel gas and solute sensors

gamma-Ray radiation grafting of polyethylene (PE) onto conductive carbon black under various conditions was investigated. In the case of 400 kGy dose of irradiation of PE-adsorbed carbon black at high temperatures near or above the melting point of PE, the grafting of PE onto the carbon black surface was successfully proceeded and the percentage of grafting exceeded 90%. Using the PE-grafted carbon black and PE, conductive composite prepared from PE-grafted carbon black and PE was prepared. The electric resistance of the composite largely increased when it was transferred from dry air to solvent vapor, such as carbon tetrachloride and cyclohexane. The electric resistance also clearly increased when the composite was immersed in n-hexane solution of tetrahydrofuran, chloroform and cyclohexane. Therefore, it was concluded that the conductive composite could be used as a novel sensor of solvent vapor and solute in n-hexane. (C) 2003 Elsevier Science Ltd. All rights reserved.