The Effect of Atmospheric Plasma Treatment on the Chemistry, Morphology and Resultant Bonding Behavior of a Pan-Based Carbon Fiber-Reinforced Epoxy Composite

A study was undertaken to evaluate the effect of atmospheric plasma treatments on the surface chemistry, morphology, and mechanical properties of graphite/epoxy composites. Characterization included contact angle measurements, XPS, FTIR, SEM and AFM. Treatment was shown to increase strength by as much as 50% relative to untreated specimens. The improvement was related to the number of passes and can be attributed to chemical surface modifications. While the total amount of oxygen on the surface stabilized quickly after a few plasma passes, the concentration of the carboxyl groups was shown to continuously increase, and correlated well with observed increases in strength.