Comparative CO2-Sensing Characteristic Studies of PEI and PEI/Starch Thin Film Sensors

In this paper, pure PEI and PEI/Starch thin film sensors were fabricated to detect carbon dioxide (CO2). Films were characterized by ultraviolet-visible spectroscopy (UV–Vis). The quartz crystal microbalance sensors (QCM), coated with the two selected films by the spin-coating method, showed good sensitivities to CO2 gas with concentrations in the range (0.1%-0.5%) at room temperature. In addition, the dependence of temperature on the properties of sensors was studied. It was found that the polyethyleneimine (PEI)/Starch nanocomposite thin film sensor exhibited a better CO2-sensing property than that of a pure polyethyleneimine (PEI) thin film sensor.