Interlock or Chemical Bond: Investigation on the Interfaceof Graphene Oxide and Styrenic Block Copolymers as Layer-by-LayerFilms

摘要

In the paper, graphene oxide (GO) and two kinds of styrenic resins, poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and maleic anhydride (MA) grafted SEBS (MA-g-SEBS), were utilized to explore the interfacial interaction of carbon-based materials and block copolymers as layer-by-layer (LBL) assembly films. The details of the interlayer interaction of the two kinds of composite films were investigated through the analysis of the mechanical properties and internal structure of the composites. For the SEBS/GO composite film, the “interlock” structure tended to form between the GO sheets and SEBS resin, and the physical “interlocking effect” could make full use of the excellent mechanical properties of GO nanosheets. As a result, both failure strength and elongation at break of the SEBS/GO composite film were enhanced by 50 and 25%, respectively. On the other hand, some different structures were found in the MA-g-SEBS/GO composite film, where the GO sheets stacked onto the resin closely because of the chemical interaction between them and no obvious “interlocks”was found within the interface, and the chemical interface interactionwas strong enough to prevent the slide of GO nanosheets under tensionafter the graphene sheets were highly oxidized, so the mechanicalproperties of the MA-g-SEBS/GO composite film couldbe also enhanced. Based on an overall consideration of the researchresults of these LBL assembled composites, choosing more perfect materialsand structures is needed, which should use physical and chemical interfacialinteractions more efficiently, to obtain better mechanical propertiesof inorganic carbon–organic resin composites.