Preparation and characterization of gas-sensitive composites from multi-walled carbon nanotubes/polystyrene

In this paper, a new kind of conductive polymer composites was fabricated by in situ polymerization of styrene (PS) in the presence of multi-walled carbon nanotubes (MWCNTs) and solution mixing of polystyrene with MWCNTs, respectively. The electrical percolation behaviors of the composites and their resistance responsivities against various organic vapors were investigated. The experimental results showed that the in situ polymerization method has more advantages to improve the dispersion of MWCNTs in PS matrix, and produces composites with high sensitivity and rate of response for the vapors of good solvents of PS at filler range from 5 to 15 wt.%. A rise in testing temperature raised the rate of response but lowered the maximum responsivity of the composites. It can be concluded that the MWCNT/PS composites developed in the present work are promising candidates for gas sensors to detect, distinguish and quantity organic vapors.