Gas sensitive vapor grown carbon nanofiber/polystyrene sensors

摘要: Abstract A new class of conductive composites with good gas sensitivity was fabricated by filling polystyrene vapor grown carbon nanofibers (VGCNF). solution mixing/solvent removal procedure used. VGCNFs form networks at fiber loadings above the percolation limit within matrix. Greatly improved conductivity is achieved relative to same volume fraction black addition when these fibers are distributed give reasonably uniform dispersions in The high aspect ratios (∼70–250 nm diameters and 5–75 μm lengths) assist forming low wt.% thresholds (below 1 wt.% fiber). Excellent 10 4 –10 5 times higher than original resistance value many saturated organic vapors a maximum response about 1.1 × 10 exposure THF 6.25 wt.% VGCNF matrix observed. declined from 2.0 × 10 15 °C 3.4 × 10 55 °C. These exhibited stable reusable vapor. Carbon black/polystyrene exhibit negative coefficient (NVC) upon swelling caused filler redistribution. In contrast, VGCNF/polystyrene more stable, much smaller NVC values due their reinforcing effects which stabilize electrical pathways. Thus, VGCNF/organic polymer sensor candidates for detecting vapors.