Volume and Composite Resistivities of Carbon Nanofibers

摘要

Carbon nanofibers can have good conductivity and sufficient length so that it is possible to fabricate electrically conducting composites with only small amounts of fiber. The volume resistivities of compacts of several types of PYROGRAF carbon nanofibers having differing surface preparation and length may be determined by squeezing the raw fibers in a die which allows in situ resistivity measurements. Volume resistivities of compacted nanofibers range from 0.03 to 3 Ohm cm, with longer fibers and those having coated surfaces exhibiting higher resistances. Resistivities of polypropylene composites fabricated with nanofibers are generally higher and range from 0.01 Ohm cm to over 1000000 Ohm cm. Long fibers lower composite resistivities, which correlate well with fiber length/diameter ratio.