Liquid sensing properties of carbon black/polypropylene composite with a segregated conductive network

Conductive carbon black (CB)/polypropylene (PP) composite with a segregated structure has been prepared by localizing CB particles preferentially at the interfaces between PP particles. Liquid sensing properties of the composite were investigated by detecting the variations of the electrical resistance toward different solvents. It is found that the composite has a good sensing selectivity. For the liquid sensing behaviors test during immersion-drying runs, a high sensing responsivity, but a poor reproducibility in 'good solvents' is observed. Higher liquid sensing responsivity and faster response rate have been achieved under a high environmental temperature or utilizing the immersion pretreatment. Based on these results, it is suggested that the segregated structure and the Flory-Huggins interaction parameter χ12, which is related to the solubility parameter, molecular volume and temperature are the key influencing parameters for liquid sensing behaviors of the conductive polymer composite (CPC).