Liquid sensing behaviors of conductive polypropylene composites containing hybrid fillers of carbon fiber and carbon black

In this paper, carbon black (CB), carbon fiber (CF), and hybrid CF/CB were introduced into polypropylene (PP) to fabricate different conductive composites by melt mixing, respectively. The combined effects of CF and CB on the electrical and liquid sensing properties of PP-based composites were investigated in detail. In virtue of the co-supporting conductive network, percolation threshold of the CF/CB/PP composite was reduced apparently upon the addition of 8 wt.% CF. For liquid sensing measurements, CF/CB/PP conductive polymer composites (CPCs) exhibited a superior liquid sensing behavior with higher responsivity, rapider response and better stability in contrast to the counterpart CB/PP. In addition, the response curves are found to be remarkably characteristic for discriminating different kinds of organic solvents. The present paper provides a new route to tailor the liquid sensing properties of CPCs.