P(VDF-HFP) Polymer as Sensing Material for Capacitive Carbon Dioxide Sensors

P(VDF-HFP) polymer is investigated through both theoretical and experimental approaches as a sensing material for capacitive CO2 sensor applications. Analysis based on the Clausius-Mossotti model shows that larger CO2 solubility and larger dielectric constant contribute to high CO2 capacitive sensitivity, which shows that P(VDF-HFP) polymer has significantly higher CO2 sensitivity compared with Teflon when they have comparable CO2 solubility, which is supported by subsequent experimental demonstration. Cross-sensitivity to humidity and temperature are evaluated and discussed for both P(VDF-HFP) and Teflon polymers. Fourier Transform Infrared spectroscopy (FTIR) analysis further reveals that the electrostatic interaction of P(VDF-HFP) with CO2 is stronger than Teflon. The theoretical analyses and experimental demonstration indicate that P(VDF-HFP) is a promising sensing material to be applied for capacitive CO2 sensors operated at room temperature.