DNA ‐Assisted CNT Self‐Assembly and Silane Modification for Enhanced CFRP /Steel Joint Interfacial Performance

ABSTRACT This study proposes an interfacial reinforcement method for CFRP/steel adhesive joints using DNA‐assisted carbon nanotube self‐assembly and silane coupling agent modification. A nanostructured interface was fabricated by dispersing DNA‐modified nanotubes (DNA‐CNTs) in a KH560 silane ethanol solution under controlled ultrasonication, and the resulting hybrid dispersion was then brush‐coated onto both the mechanically abraded CFRP and steel surfaces. Mechanical tests showed that the surface modification significantly increased the ultimate load from 71.26 kN (untreated) to 90.31 kN (optimized treatment), with corresponding bond strength improving from 14.25 to 18.06 MPa. Microscopic characterization revealed a uniform silane film with an interwoven CNT network on the steel surface, effectively hindering crack propagation. The failure mode shift toward cohesive failure confirmed the enhanced interfacial bonding quality. This DNA‐assisted strategy offers an effective approach for developing high‐performance composite/metal joints.