Effect of carbon nanotube length and density on the properties of carbon nanotube-coated carbon fiber/polyester composites

Carbon nanotubes (CNTs) have been synthesized on the surface of carbon fiber/fabric using catalytic chemical vapor deposition (CVD) at a temperature of 550 °C. A coating of Ni catalyst on the fiber surface is applied using the electroless dip coating method. The dependence of the length and quantity of CNTs on the growth time is studied by varying the run time of the CVD reactor from 5 to 25 min. Scanning electron microscopy shows good coverage of the carbon fiber surface by the CNTs. It is observed that both the length and density of CNTs are functions of the growth time. Up to a critical growth time, both the storage modulus and the interfacial shear stress of CNT-coated carbon fiber/polyester composites are seen to increase substantially.