Interlock or Chemical Bond: Investigation on the Interface of Graphene Oxide and Styrenic Block Copolymers as Layer-by-Layer Films

Abstract

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 interaction was strong enough to prevent the slide of GO nanosheets under tension after the graphene sheets were highly oxidized, so the mechanical properties of the MA- g -SEBS/GO composite film could be also enhanced. Based on an overall consideration of the research results of these LBL assembled composites, choosing more perfect materials and structures is needed, which should use physical and chemical interfacial interactions more efficiently, to obtain better mechanical properties of inorganic carbon–organic resin composites.

Functionalized POSS-Modified SEBS-Based Composite Anion-Exchange Membranes for AEMFCs

“…Poly­(styrene- b -(ethylene- co -butylene)- b -styrene) (SEBS) is widely used as a basic material in rubber preparation on account of its low price, aging resistance, and strong plasticity . SEBS is also chosen as a representative backbone of AEMs because of the convenience in its functionalization and ionization. − However, as a very soft thermoplastic rubber, SEBS has high swelling and leads to a decrease in mechanical properties, which is not suitable for the assembly of membrane electrodes . To improve its mechanical property, studies on SEBS via grafting inorganic fillers, such as graphene oxide (GO) − and SiO 2 , were reported and showed impressive results.…”

“…SEBS is also chosen as a representative backbone of AEMs because of the convenience in its functionalization and ionization. − However, as a very soft thermoplastic rubber, SEBS has high swelling and leads to a decrease in mechanical properties, which is not suitable for the assembly of membrane electrodes . To improve its mechanical property, studies on SEBS via grafting inorganic fillers, such as graphene oxide (GO) − and SiO 2 , were reported and showed impressive results. Besides, to improve the ion conductivity of AEMs, developing a composite membrane seems to be an effective and uncomplicated strategy for the improvement of AEMs.…”

Construction of a Self-Assembled Polyelectrolyte/Graphene Oxide Multilayer Film and Its Interaction with Metal Ions

“…Graphene oxide (GO), as a two-dimensional nanomaterial with a single-atom thickness, contains functional groups such as carboxyl and hydroxyl groups, making it attractive for chemical and functional modifications and metal ion binding. − Because of its negative charge, GO is a very attractive building element for LbL self-assembly strategies. It can be combined with positively charged polyelectrolytes to prepare polyelectrolyte/GO multilayers, , reveal the interaction of polyelectrolyte/GO multilayer films with metal ions, and develop ion adsorption and sensing detection materials . These recent examples provide the ingredients to effectively monitor the construction process of GO/polycation-based LbL self-assembled multilayer films and to study the interactions between the resulting multilayer films and (heavy) metal ions.…”