Sensor properties of filled polymer composites

Abstract

Polymer composite films are proposed as potential materials for use in sensing the gases and vapours of organic liquids. The basic principle of the operation of the sensor relies on a marked change in the electroconductivity of the polymer composite system when the filler concentration is near the percolation threshold. We propose a simple model that agrees with the experimental findings. The model assumes the formation of a hopping conductivity infinite cluster before the true percolation threshold of the system is reached. The conductivity response is determined by the dependence of the hopping probability on the relative permittivity of the polymer matrix. Humidity sensors, based on the proposed principles, are described.