Effects of acid treatment and plasma micromachining on the surface properties of carbon fibers

The effects of strong acid and weak acid treatment on the carbon cloth (CC) surface assisted by plasma micromachining are investigated in terms of the morphology, chemical composition, and surface free energy. Different surface properties are observed and protein adsorption is investigated to assess the biocompatibility. The combined plasma and acetic acid treatment leads to more surface oxidation due to the large number of carboxyl groups on the CC surface and surface energy increase by 18.6 times. Since the effects of acetic acid are relatively mild, few morphological changes are found, but protein adsorption decreases by about 30% after the surface treatment compared to the untreated CC. The combination of plasma and weak acid treatment is not only simple and convenient, but also very effective in controlling protein adsorption on biomedical carbon cloth.