Effect of Carbon Nanotube Growth Conditions on Strength and Stiffness of Carbon and Glass Fiber Polymer Composites

Abstract

Carbon nanotubes (CNTs) and Carbon nanofilaments (CNFs) were grown on the surface of carbon and glass sheets from fuel rich ethylene/oxygen combustion mixtures on certain catalytic metals. Employing a well-known catalyst deposition method, incipient wetness allowed growing CNTs/CNFs on the surface of carbon and fiber glass bidirectional sheets. Two-layer fiber reinforced polymer (FRP) composite plates were fabricated using a vacuum assisted hand lay-up technique of the carbon and glass fiber sheets after CNTs/CNFs were grown using 1.0% Nickel deposits. In this paper we report on the growth process and we examine the significance of the CNTs/CNFs growth conditions including the sizing burning temperature (250 and 500 oC), the growth time period and the fiber base type (carbon or glass) on the strength and stiffness of this new multi-scale FRP composite. The ultimate tensile strength, tensile modulus (stiffness) and ultimate strain at failure was determined using ASTM D3039 test. It is shown that the sizing burning temperature has a significant effect on the strength and strain at failure of the new carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composites. Little effect on the composite stiffness was observed. Microstructural investigations of the failed specimens shed light on the fracture surface of the multi-scale CFRP and GFRP composites.