Polar tri-glycol side chain for enhanced detection to low concentrations of NO2 at room temperature

Abstract

It has been widely studied the impact of polar side-chain on the modification of conjugated polymers and the thermoelectric properties of composites, but relatively little research has been carried out in the gas sensing field. In this study, two π-conjugated polymers PFTC8 and PFTO with similar backbone but different polar-side chains were synthesized. The separation efficiency of the polymers for semiconducting single-walled (sc-SWCNTs) and the NO2 sensing performance were also investigated. It was found that the introduction of the polar side chains not only enhanced the sorting efficiency of the polymer for sc-SWCNTs (greater than 99 %), but also further improved the responsive performance of the sensor to NO2. After the introduction of polar side chains, the response value of the composite PFTO@sc-SWCNTs towards 1 ppm NO2 was achieved to be 21.7 % at room temperature. Furthermore, the response time (Tres = 23 s) and recovery time (Trec = 134 s) of PFTO@sc-SWCNTs to 1 ppm NO2 were also greatly shortened. The strategy for improving the NO2 gas response performance by introducing polar side chains is proposed.