Fluorinated Nanoparticles in Conjugated Polymer for Volatile Organic Compounds Sensor

Human health care and environmental protection have growing attention in recent years, and are no longer an acceptable trade-off for economy for the majority of people. The most hazardous and toxic chemicals are volatile organic compounds (VOC), which are mainly released from oil refinery, factory ,household paints, etc. Although VOCs are used extensively and known for their hazardous , little protective measurements have been developed to provide effective warning signal before the harmful high level of VOC. These invisible and toxic VOC put the human safety into dangerous condition without notice. Thus, there is an urgent need to develop a high efficient, low cost VOC sensor to ensure the health and safety of mankind. We have demonstrated before, a low cost and effective VOC sensor can be fabricated from P3HT/PC71BM nanocomposite on glass substrate. In the work, we further improve the sensitivity of VOC sensor 2-3 times by incorporating fluorinated PC71BM in the nanocomposite. We also utilize GISAXS/GIWAXS, AFM, XPS etc instruments to characterize the structure of sensing layer. As the result, we correlate the morphology of sensing layer to the performance of VOC sensing, which reveals that the improved dispersion of F-PC71BM in P3HT is the key factor to improve the sensitivity of sensor. Besides the study of the performance and morphology of VOC sensor, stability test of VOC sensor under various temperature was also conducted to estimate the life time of the sensor. Our sensor needs to be stored under 25oC temperature for a life more than 3 months. Furthermore, we show the life time of sensor can be doubled by coating the sensing layer onto the conductive substrate ITO.