Application of ionic liquid doped ionomers for organic vapor sensing

In this work we explore the use of room temperature ionic liquid doped ionomers as the sensing material for volatile organic compounds (VOCs). Pixels of a monolithic, micromachined quartz crystal resonator (μQCR) array were functionalized using a sulfonated, aromatic, high thermal stability polymer as a template which is able to contain high amount of ionic liquids (up to 200 wt %). Ionic liquid: [C₄mim][BF₄] (1-butyl-3-methylimidazolium tetrafluoroburate) was used as the detection material. Exposure to VOCs results in mass loading and changes in the viscoelastic properties of the ionomer and manifests as changes in the frequency and phase of the quartz resonators.