Hydrogen-bond acidic organic compound-sensitized ionic gel for dimethyl methylphosphonate detection
Qiang Wu, Yubin Yuan, Menglong Jiao, Xuming Wang, Weihua Liu, Xiangrui Bu, Chuanyu Han, Xin Li, Xiaoli Wang
Abstract
Due to the threat of chemical warfare agents (CWAs), there is a pressing need to develop miniaturized gas sensors with fast response, high sensitivity and good stability. Herein, hexafluoroisopropanol aniline (HFIPA), a hydrogen-bond acidic organic compound, is embedded into a cross-linked poly(ethylene glycol) diacrylate/ionic liquid (PEGDA/IL) matrix as a sensitive film for detecting sarin simulant dimethyl methylphosphonate (DMMP). We find that the IL in the film constructs efficient gas transport channels, improving the absorption-desorption kinetics of DMMP molecules. The introduction of HFIPA enhances selectivity and sensitivity to DMMP through hydrogen bonding interaction. As a result, the SAW gas sensor based on PEGDA/IL-HFIPA ionic gel exhibits a fast response/recovery time of 28/53 s to 20 ppm DMMP and a low detection limit of 0.2 ppm at room temperature. By comparing with PEGDA-HFIPA, PEGDA/IL-HFIPA shows excellent anti-humidity interference ability, which is also attributed to the stable gas transport channels constructed by IL. Overall, this work develops a novel strategy to improve the gas-sensing properties of organic polymer materials.