Property enhancement of a carbon fiber/epoxy composite by using carbon nanotubes

We investigated the effect of carbon nanotube (CNT) modifications on the flexural and wear behaviors of multiscale carbon/CNT/epoxy composites in this study. Carbon/epoxy woven composites and two types of multiscale carbon/CNT/epoxy composites were fabricated by incorporating woven-type carbon fibers into epoxy matrices modified with 2 wt% acid-treated and silane-treated multi-walled carbon nanotubes (MWCNTs). Three-point bending and ball-on-disk wear tests were performed on the three composites. The results showed that the flexural moduli and strengths of carbon/CNT/epoxy composites were greater than those of carbon/epoxy composites, regardless of CNT modification. Specifically, the flexural modulus and strength of the silane-treated specimens were 10% and 15% greater, respectively, than those of the acid-treated samples. The results also showed that the wear properties of carbon/epoxy composites are improved by the addition of CNTs. In addition, the wear properties of silane-treated samples were superior to those of acid-treated samples. Scanning electron microscopic examination of fractured and worn surfaces showed that the improvement in the flexural and wear properties of the silane-treated carbon/CNT/epoxy composites was attributed to the improved dispersion of CNTs in the epoxy and the better interfacial characteristics caused by the silanization of the CNTs.