Establishment of a novel hierarchical structure based on metal-organic framework on the surface of carbon fibers for improving interfacial properties

The performance of carbon fiber reinforced composites (CFRC) is positively correlated with the interphase properties between resin and carbon fiber (CF). With purpose of improving interface properties of the CFRC, a novel hierarchical reinforcement structure (ZnO-MOF) containing zinc oxide (ZnO) and metal-organic framework (MOF) was built on the surface of CFs. The sheet-like ZnO-MOF structure can strengthen the mechanical interlocking between CFs and epoxy, and introduced a dual-platform modulus transition layer to the composite interfacial region which can deliver load from resin to CFs efficaciously. Compared with the commercial CFs, the interfacial shear strength (IFSS) and transverse fiber bundle tensile (TFBT) strength of the modified T700 CF was increased by 64.70% and 51.81%, respectively. These results indicate that the construction of the ZnO-MOF structure is a promising design solution with practical value in endowing CF composites more excellent interfacial properties. [Display omitted] •A novel ZnO-MOF structure was established to enhance the interfacial properties.•A dual-platform modulus transition layer was introduced into the composite interface.•The MOF prepared by this facile method had smaller and more uniform particle size.•The T700 CF/epoxy composites showed improved IFSS and TFBT strength.