Two-dimensional polydopamine nano-protrusion-modified graphene oxide encapsulation of cylindrical carbon fiber by vacuum filtration to strengthen the interphase of epoxy composites

Abstract

Interfacial delamination is an everlasting problem that exists in carbon fiber reinforced polymer composites and restricts their ability to undertake greater shear load. Herein, vacuum filtration technique is first successfully utilized to realize the functionalization of cylindrical carbon fiber by two-dimensional graphene oxide (GO) and polydopamine nano-protrusions modified GO (GOPDA) as a rapid, simple and versatile means to realize the improvement of interfacial adhesion of epoxy composites. Compared to the GO modifier (37.6% augmentation), the GOPDA addition results in higher gain in interfacial shear strength (68.4%) over that of de-sized fiber. This belongs to that the adherence of smaller-sized GOPDA and its nano-protrusion structure facilitate the high surface energy, excellent wetting, mechanical interlocking and covalent linking with epoxy resin. Our research highlights the great possibility to implement vacuum filtration to modify the traditional circumferential fiber and realize the interphase optimization of composites.