Interaction of ZnO Nanowires with Carbon Fibers for Hierarchical Composites with High Interfacial Strength

Abstract

When grown on the surface of carbon fiber, vertically aligned arrays of ZnO nanowires have been shown to increase the interfacial shear strength without decreasing the in-plane properties of the composite. Analysis of the failure surface indicates that the ZnO debonds from the carbon fiber which combined with the higher interfacial shear strength, indicates that the ZnO more strongly adheres to the carbon surface than epoxy adheres to the carbon surface. Previous work was unable to identify the specific chemical interaction that enhanced the ZnOcarbon fiber interface, however it hypothesized that the presence carboxylic acid groups on the fiber were responsible. In this study an aramid fiber is used to elucidate the surface interaction since it can be produced with no carboxylic acid or with these groups through functionalization. The model fiber demonstrates that only fibers with carboxylic acid groups experience increased interfacial strength from the ZnO nanowires. The interaction between ZnO and carboxylic acid groups is verified to be critical to the enhancement of the interfacial strength in carbon fiber -ZnO nanowire -epoxy composites.

Tailored interyarn friction in aramid fabrics through morphology control of surface grown ZnO nanowires

“…A new approach for enhancing the interyarn friction can be realized by utilizing the recent development of ZnO nanowires as a strong whisker interphase in carbon fiber reinforced polymer composites [19][20][21][22][23][24]. In previous experimental and analytical studies, it was shown that the growth of vertically aligned ZnO nanowires on carbon fiber led to improvements of interfacial shear strength as well as enhanced energy dissipation [20][21][22][23][24][25].…”

“…In previous experimental and analytical studies, it was shown that the growth of vertically aligned ZnO nanowires on carbon fiber led to improvements of interfacial shear strength as well as enhanced energy dissipation [20][21][22][23][24][25]. The strong nanowire interface is created through increased surface area, which is advantageous for van der Waals bonding, and strengthened mechanical interlocking between the nanowires and epoxy matrix [23].…”

Enhanced vibration damping of carbon fibers-ZnO nanorods hybrid composites

“…Alternatively, the concept of hybrid fibers has emerged. These fibers comprise standard structural fibers (e.g., carbon, fiberglass, aramid, or SiC) with surface grown nano-fibers or nanotubes (e.g., carbon nanotubes 1 or ZnO nanorods 2 ). The motivation of growing 1D metal oxide nano-structures in general and ZnO nanorods in particular over structural and conductive fibers commences from their contribution to a wide range of applications such as smart materials for energy scavenging, 3 improved mechanical behavior through better matrix-to-fiber adhesion, 2,4 gas sensors, 5 field emission, 6 photo-electrochemical cells, 7 surface polarity shielding, 8 and improved damage resistance.…”

“…2 Selective growth of nanotubes on designated surfaces yielded better damping where up to 1400% improvement in the damping figure of merit was reported. 21 Zinc oxide has high piezoelectric tensor providing large electromechanical coupling due to its wide band-gap (3.37 eV) and the absence of an inversion symmetry in its wurtzite structure.…”

“…Hydrothermal synthesis is a low-temperature solution-based growth which can be conducted at 60 C-90 C. synthesis on the base carbon fibers, mechanical tests were performed on single carbon fibers coated individually with ZnO nanorods. 2,4,27 However, FRPs utilize bundles of woven fibers rather than single fibers and the weave architecture plays a critical role on the composite properties.…”