Novel vapor sensor based on chemical coupling effect of composite

摘要

A novel sensing material has been developed for constructing a sensor of solvent vapours using chemical coupling effect of composite, which is different from conventional electron-moving chemiresistors for use as gas sensors. The composites consisting of polymer loaded with conductive filler near the percolation threshold exhibit sensitive characters comparable to that of conventional semiconductor gas sensor but can be realized with much simpler technology and operated at room temperature This sensor can also obtain better selectivity by choosing different polymer matrix. Theoretic analysis and experimental results show sensitive properties of composite sensor greatly depend on composition of composite and grain size of conducting particles. In general resistance variation R.R. in the presence ofnvapor is more for higher volume fraction of filler and larger grain size of conducting particles