The Effect of Electrolyte on Surface Composite and Microstructure of Carbon Fiber by Electrochemical Treatment

The new method of electrochemical alternating anode and cathode was used to treat carbon fibers (CFs) in this article. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to study the surface composition and surface microstructure on the PAN-based carbon fibers with electrochemical alternating cathode and anode treatment in different electrolytes. Results show that the method can make the surface of the carbon fiber grooves deepen; when the electrolyte is sulfuric acid, phosphoric acid, sodium sulfate and sodium phosphate, the C content on the surface of the carbon fiber is reduced while the O content increased, and the little influence of ammonium bicarbonate on the surface element of the carbon fiber was discovered; However, each electrolyte chosen can significantly increase the oxygen functional groups COOH content on the carbon fiber surface. Treating carbon fibers in different electrolytes, the anodic oxidation mechanism of the process is different. Treated carbon fibers with electrochemical alternating anode and cathode, the crystal lattice spacing d(002) and the diameter of the carbon fiber increase at the same time.