Gas Sensor for Volatile Organochlorine Compounds Using Percolation Conduction of Organic Montmorillonite-Carbon Composites

Abstract

Gas sensor material, which shows a resistivity change in response to change in concentration of volatile organochlorine compounds, is first developed based on a percolation principle. A composite of organic montmorillonite and carbon shows a reversible resistivity change in response to the concentration change of chloroform, dichloromethane, trichloroethylene, tetrachloroethylene, and tetrachloromethane, because the resistivity of the composite is closely dependent on the volume fraction of the insulating phase and the volume of the insulating phase is increased by incorporation of the organochlorine molecules. The response time is substantially improved by fabricating thick-film composites using classified organic montmorillonite.