Superior interlayer and compression properties of CFRPs due to inter-fiber “bridges” built by functionalized micro-nano scale graphene oxide synergistically

In this work, micron scale GO 20∼30 μm sheets were modified by five kinds of modifiers and co-dispersed with nano scale GO 200 nm to promote their dispersion in epoxy resin. Meanwhile, ultra-thin carbon fiber technology was adopted to prepared carbon fiber reinforced polymer composites (CFRPs). Contrastive experiments were carried out to explore the influence of surface functionalization effect and synergistic dispersion effect of nano scale GO 200 nm on the dispersibility of micron scale GO 20∼30 μm and the “bridges” built by it between carbon fibers in the composites. The interlaminar and compression properties of CFRPs gained remarkable optimization due to the “bridges” built by micron scale GO 20∼30 μm . Prominently, the lateral fiber bundle test (TFBT), the interlaminar shear strength (ILSS) and compressive strength of GO 200 nm  + GO 20∼30 μm-D400 /EP/CF 24 mm composites reached 51.7 MPa, 86.9 MPa, 1397.9 MPa which were increased by 140.4 %, 31.4 % and 49.0 % respectively compared with GO 20∼30 μm /EP/CF 24 mm composites.