Effects of Atmospheric DBD Plasma Treatment on the Surface Properties of PAN-Based Carbon Fiber

Plasma treatment has been known as an effective way to improve the surface bonding between the reinforcement material and the matrix, by modifying the surface morphology and the chemical composes of the material. In order to investigate the effects of atmospheric dielectric barrier discharge (DBD) plasma treatment on the surface properties of polyacrylonitrile-based (PAN-based) carbon fiber, atomic force microscope(AFM), X-ray photoelectron spectroscopy(XPS), and contact angle test were introduced to compare different treatment duration. The interfacial adhesion of carbon fiber/epoxy (CF/EP) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. And the tensile strength test and Weibull analysis were carried out to observe whether the etching could affect the strength. The results prove that the DBD plasma improves the surface properties of the carbon fiber. Further, when the treatment time was around 90 s, the roughness and oxygen containing group of the carbon fiber reached the peak values. Also, the fiber showed the best adhesion to the polymer in contact angle test and the optimum interfacial shear strength (IFSS) in fragmentation test. The Weibull analyses of the tensile data revealed no substantial changes in the tensile strength within the treatment time of 180 s.