Nanotube surface functionalization effects in blended multiwalled carbon nanotube/PVDF composites

摘要

A mixed fill system of multiwalled carbon nanotubes (MWCNT) and hydroxylated MWCNT (HO-MWCNT) in a poly(vinylidene fluoride) (PVDF) matrix was investigated to improve nanotube dispersion and enhance electrical percolation for the bulk nanocomposites. Nonfunctionalized MWCNT were blended at various concentrations into dimethylformamide solutions containing PVDF with 0, 5, or 10 wt % HO-MWCNT. Composite samples prepared from these solutions were examined by four-point probe resistivity measurements. The percolation threshold decreased from 0.49 wt % MWCNT in binary MWCNT/PVDF composites to 0.25 wt % for ternary composites containing MWCNT/HO-MWCNT/PVDF, with either 5 or 10 wt % HO-MWCNT. In the case of the ternary composite with 10 wt % HO-MWCNT, the lowest fill percent of MWCNT (0.25 wt %) measured a conductivity that was three orders of magnitude higher than the binary MWCNT/PVDF composite containing twice the concentration of MWCNT (0.5 wt %).