The effects of plasma surface treatment on the mechanical properties of polycarbonate/carbon nanotube/carbon fiber composites

The effects of plasma surface treatment on the mechanical properties of multiscale hybrid composites consisting of polycarbonate (PC), carbon nanotube (CNT) and carbon fiber (CF) were investigated. Dynamic mechanical properties and impact energy absorption of multiscale hybrid composites fabricated under various processing conditions were measured and correlated with surface roughness and surface functionality. The highest room temperature storage modulus (E') of 39 GPa and absorbed impact energy of 5.3 J were obtained from the plasma treated PC/CNT/CF composite, which are increases by 387% and 194%, respectively, as compared to the neat PC/CF composite. Although the plasma treatment was more efficient for the PC/CF composites rather than the PC/CNT/CF composites, hybridization of CNT showed synergistic effects on the enhancement of mechanical properties due to the combination of increased surface roughness and functionality as well as the bridged modulus gap between PC and CF.