Design, preparation and characterization of modified PAN-based carbon fiber by an anodic oxidation process: what is the electrolyte role on the morphology and surface properties?

Abstract

PAN‐based carbon fiber surface properties modified by electrochemical oxidation process were studied by different methods. Functional groups created during the electrochemical oxidation process were characterized by potentiometric titration and spectroscopic (ATR-FTIR) methods. Hydrogen atoms of carboxylic groups on surface of modified carbon fiber react with hydroxyl groups of sodium hydroxide and pristine alkalis were determined by titration method. The increase in oxygen content on the carbon fiber surface modified by ammonium oxalate monohydrate electrolyte’s ((NH4)2C2O4.H2O) was shown by EDX spectrum. The surface topography and effect of electrochemical alteration were studied using atomic force microscopy (AFM). The AFM results showed that the porosity of the modified carbon fiber surface increased during the electrochemical oxidation process. The results showed that with the increase of 30% of carboxylic groups on the surface of carbon fiber and the increase in surface etching, the chemical properties and morphology of the fiber surface improved by 25–30% during the electrochemical oxidation process. Graphical abstract: (Figure presented.). © Iranian Chemical Society 2023.