Aligned carbon nanotube webs in aerospace carbon fibre reinforced polymer composites for anti-icing/de-icing

Carbon fibre reinforced polymer (CFRP) composite is the predominant material in the latest generation of wide-body passenger aircraft and also extensively present in advanced narrow-body aircraft such as the Bombardier C-Series, owing to its superior specific strength and stiffness. However, the relatively low thermal conductivity and the ever greater emphasis on energy efficiency, demand a new approach to prevent ice accretion and retention on susceptible aerodynamic surfaces. Carbon nanotubes (CNTs) possess remarkable thermal and electrical conductivity and exceptional specific strength and stiffness, and thus are a promising option to achieve anti-icing/de-icing while maintaining the mechanical properties of the CFRP composites. The CNT webs were obtained by directly drawing from CNT forests, which were specially grown by chemical vapor deposition, and laid between copper foil buses. The CNTs are highly aligned along the web-draw direction. The effect of layup curing pressure and a CNT web interlayer on CFRP composites were investigated. The composites cured under high-pressure have higher fibre volume fraction, as well as higher thermal and electrical conductivity. With a CNT web interlayer added at a single interface of an 18 ply laminate, the thermal conductivity increased by 3.9%. With the same input power, composites with the carbon fibres parallel to copper buses have smaller heating area and higher surface temperature compared with the perpendicular ones. Through tailoring the pressure, carbon fibre layup and CNT interlayer, an efficient and reliable electro-thermal ice protection system could be obtained.