Structure and Properties of Carbon Fiber Surface

Abstract

Surface structural elements, surface properties and adhesion to resins are reviewed on PAN-based carbon fibers. The surface active carbon atom concentration of carbon fibers without surface treatment decreases with increasing fiber young's modulus. The increases in specific surface area and active surface area rate by surface treatment are observed on commercial carbon fibers. The surface roughness, defined using the BET area and the geometric surface area, of every carbon fiber is higher at a higher degassing temperature than that at a lower degassing temperature. The surface treatment by anodic oxidation technique leaves decomposition product, lowering adhesion to the resin, on the carbon fiber surface in an acidic solution, but not in alkaline solution. There is a linear relationship between the active surface area rate and the surface oxygen concentration for every type of carbon fiber produced by every manufacturer. The interfacial shear strength in carbon fiber-resin systems depends greatly on the active surface area rate and/or the surface roughness.