Study of the impact of UV radiation on NO_2 sensing properties of graft comb copolymers of poly(3-hexylthiophene) at room temperature

摘要

In this paper graft copolymer of poly(3-hexylthiophene) and poly(ethylene) glycol on the polymethylsiloxane core are investigated as a receptor material for resistance gas sensor. Sensor response to 5 ppm of NO_2 and its recovery after the interaction with NO_2 are studied at different conditions: room temperature (RT), RT with ultraviolet (UV) radiation and at elevated temperature (50 °C). Results shows that sensor regeneration occurred faster at RT with UV than at 50 °C in dark conditions. The sensor response at RT is also higher than at 50 °C. The mixed operation conditions, namely dark conditions for adsorption and UV for desorption, provides high sensor response (3590% for 5 ppm of NO_2) and relatively good regeneration (250% deviation from base-line after 30 min). Thanks to this investigated graft copolymers are promising receptor materials for chemical NO_2 sensors operating at RT.