Silane modification of carbon nanotubes and its effects on the material properties of carbon/CNT/epoxy three-phase composites

Carbon/CNT/epoxy three-phase composites were fabricated by incorporating woven carbon fibers into epoxy mixed with multi-walled carbon nanotubes (MWCNTs). Three carbon/CNT/epoxy composites were fabricated containing unmodified, acid-modified, and silane-modified CNTs at 1 wt.% to investigate the effects of the silane-modified CNTs on the mechanical, thermal, and electrical properties of the three-phase composites. The results showed that the elastic modulus and tensile strength of the carbon/CNT/epoxy three-phase composites were improved by silane modification of the CNTs. Specifically, the elastic modulus of the silane-modified carbon/CNT/epoxy composite was approximately 13% and 18% higher than that of the acid-modified and unmodified composites, respectively. The tensile strength of the silane-modified carbon/CNT/epoxy composite was 8.4% and 15.8% higher than that of the acid-modified and unmodified composites, respectively. In addition, the thermal properties and electrical conductivity of the carbon/CNT/epoxy composites were improved due to silane modification of the CNTs.