Surface and wettability property analysis of CCF300 carbon fibers with different sizing or without sizing

To analyze the role of sizing on carbon fibers and the mechanism of adhesion in CF/polymer matrix composites, scanning electronic microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and dynamic contact angle analysis (DCAA) were selected to characterize the different properties between two types of sizings on carbon fiber CCF300. The results of surface roughness obtained from SEM and AFM images showed that the sizings smooth the surface of CCF300. In addition, the percentage of surface polar functional groups on sized CCF300 decreased slightly after sizing. In another hand, the total surface energy and the polar component of surface energy of the sized CCF300 decreased slightly compared to the unsized CCF300, and the J4 sizing has the more influence.