Given that the strength of near resin has decreased due to moisture exposure, as shown in fig.9, it can be proposed that the reinforcing effect of CNFs is likely due to increased traction due to the swelling of epoxy. It has been shown that cured epoxy resins will swell by approximately the volume of water absorbed when exposed to moisture. A single debonded fractured CNF is shown in Fig.15, where turbostratic carbon layers have broken and slide over graphitic layers. The fiber also shows cup and cone fracture that represent the stacked cup structure of the vapor grown CNFs as observed in previous CNF fracture studies. In comparing the elongated, deformed fiber with the morphology of the surface indent of the original fiber position, it can be proposed that the fiber carried load even after fracture of the matrix thus assisting in strength retention under weathered conditions.