Zeolitic imidazolate framework-8 nanocrystals synthesized and decorated carbon fibers by electrophoretic deposition for enhancing interfacial properties of epoxy-based composites

Zeolitic imidazolate framework-8 (ZIF-8) was used to enhance the interfacial strength of composites due to its large specific surface area, uniform pore size, and high stability. Morphology-controllable ZIF-8 nanocrystals were synthesized by solvent method and a layer of small-sized and height crystalline ZIF-8 was deposited on carbon fibers via an efficient electrophoretic deposition (EPD) way. The results showed that interlaminar shear strength (ILSS) and tensile strength (TS) of carbon fibers/epoxy composites and the TS of carbon fiber were enhanced by 43.56% and 25.48%, respectively. The strong interfacial adhesion strength between carbon fibers and epoxy was attributed to improving the wettability, ionic interaction and the mechanical interlocking effect induced by porous ZIF-8, which led to effective energy absorption and load transfer. This highly efficient and controllable method is believed to improve the mechanical properties of carbon fiber composites for a wide range of industrial uses. Highlights: ZIF-8s in different sizes and morphology were synthesized by solvent method. MOF was deposited firstly onto carbon fibers though electrophoretic deposition. Materials Studio was used to evaluate the strong anchoring strength. ILSS of composites was enhanced by 43.56%.