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New progress achieved in surface treatment technology for high-modulus carbon fibers at Shanxi Coal Chemical Research Institute. Author/Source: Shanxi Coal Chemical Research Institute. Date: 2019-06-10. Clicks: 615. Due to the inertness of the carbon fiber surface, stress loads cannot be effectively transmitted between the carbon fibers and the matrix material in composite materials, which directly affects their performance and limits their widespread use. The anodization method is primarily employed in industry to address this issue. High-modulus carbon fibers have larger surface grain sizes, better rigidity, poorer resistance to bending, and greater surface inertness (Figure 1). Using traditional anodization methods for surface treatment results in many fibers becoming frayed or broken, as well as uneven surface treatment effects; this leads to significantly weak interfacial bonding properties in the composite materials. Recently, the carbon fiber surface engineering research group at the Shanxi Coal Chemistry Institute made new progress in surface modification. The research team in this project group used a new type of contactless electrochemical treatment method to treat high-modulus carbon fibers. Through process design and optimization of the processing conditions, good treatment results were achieved, and wear of the fiber strands by the guide roller was effectively reduced; a continuous surface treatment test line for high-modulus carbon fibers was established. According to the statistics on the results of continuous testing: (1) This process causes no significant damage to high-modulus carbon fibers, and it can **reduce the occurrence of fraying and breaking of such fibers during the surface treatment process ； (2) After surface treatment, the elemental composition on the carbon fiber surface is uniform (Figure 2) and adjustable ； (3) The interfacial shear strength value with epoxy resin increased by 55.2% after evaluation ； (4) According to evaluations by third-party institutions, the interlaminar shear strength of the epoxy resin composite can reach 80 MPa, and its bending strength can reach 340 MPa, both of which are significantly higher than the values reported in domestic and international studies to date. This method overcomes the inherent defects of traditional anodization processes; it is environmentally friendly, and it provides new approaches and technologies for the continuous production of high-performance carbon fibers, especially those with high modulus, as well as for their applications. These research findings were presented as an oral presentation at the 2019 SAMPE conference.