Influence of rare earth treatment on interfacial properties of carbon fiber/epoxy composites

In this work, the effect of soaking and irradiating in praseodymium nitrate solution on the surface physicochemical properties of carbon fibers and interfacial properties of composites has been investigated, and the interfacial adhesion mechanism of treated carbon fiber/epoxy composite was analyzed. It was found that both of immersion and irradiation lead to an increase of fiber surface roughness, improvement of oxygen-containing groups, enhancement of disorder degree and introduction of praseodymium element on carbon fiber surface. As a result, the coordination linkage between fibers, praseodymium ion and matrix is formed and the interlaminar shear strength (ILSS) of composites is increased, due to the improvement of interfacial adhesion between fibers and matrix resin. Moreover, γ-ray irradiation treatment is superior to immersion treatment in promoting interfacial properties owing to the increase of carboxyl and carbonyl.