Effect of TiO2 nanoparticles on the resistivity and gas-sensing performance of poly(vinyl chloride)-expanded graphite composites

Composites of poly(vinyl chloride) (PVC) and TiO2-modified expanded graphite (EG) have been prepared, with TiO2 contents on the EG surface from 0 to 20 wt % and EG contents from 0 to 100%, and their structural, electrical, and gas-sensing properties have been studied. The gas-sensing performance of the composites was assessed using, acetone, toluene, ammonia, and ethanol. The results demonstrate that, by varying the composition of the composites, one can control their percolation threshold, electrical properties, and gas-sensing performance (the time needed for the gas response to reach its maximum, adsorption-desorption rate, and selectivity).