Processing and evaluation of a carbon fiber/epoxy composite reinforced in the interlaminar region with carbon nanotubes and nanofibers

This study demonstrates that introducing Carbon Nanotubes (CNTs) and Vapor Grown Carbon Fibers (VGCFs) into the interlaminar region of a carbon fiber/epoxy composite can enhance the resistance to delamination of the material. Delamination is a critical failure mode of laminated composites, materials widely used for aerospace applications, and previous work demonstrated that CNTs can be used to address this problem. In this thesis a new method to increase resistance to delamination is proposed. The approach consists of using VGCFs and CNTs simultaneously so that a synergistic effect in the enhancement of the mechanical properties of the composite is obtained. The nanocomposites were created using a spraying technique, followed by a Vacuum Assisted Resin Transfer Molding (VARTM) process. A maximum toughness increase of 51% with respect to the un-reinforced material was obtained when 0.025 wt% VGCF and 0.025 wt% CNT were combined, a result attributed to synergism occurring between the nanomaterials.