Abstract
An organic-inorganic nanocomposites composed of chitosan and CuO-Fe3O4 nanopowder with a particle size of 30 +/- 10 nm was synthesized and used to prepare sensors pellets of 10 mm i.d. and a thickness of 1 +/- 0.1 mm under pressures between of 187 to 565 MPa. A silver paste was deposited on the pellets to introduce electrodes. It is found that the impedance of the material changes with relative humidity (RH) by up to -819.4 k Omega center dot%(-1) RH, and with temperature by up to -378.0 k Omega center dot A degrees C-1. Response and recovery times for humidity sensing are 20 s and 50 s, correspondingly. The sensor works best in the 20-80 A degrees C temperature range and covers the complete RH range.