Correlation between Molecular Structure and Interfacial Properties of Edge or Basal Plane Modified Graphene Oxide

Abstract

Although graphene oxide (GO) has been reported to be able to be edge functionalized or basal-plane functionalized separately, no research has been done on comparing both the molecular structure and interfacial properties of them. In this study, an alkyl amine was grafted to the epoxy group on the basal planes of GO (b-GO) and carboxyl group at the edges of GO (e-GO) separately by using different synthetic approach. With the combination of various molecular structure and morphology characterization methodologies, we proved that the reaction site for e-GO was only with the carboxyl group at the edge of GO and that for b-GO was epoxy group on the basal plane of GO, indicating that GO could be controllably functionalized (fGOs), and the structure of fGOs could be tuned. Study of the interfacial behavior of fGOs at liquid−liquid interface showed that the interfacial tension reducing capability of e-GO was broader than that of b-GO, and for alkyl oil phase, b-GO was slightly better than e-GO, and both were better than traditional nonionic surfactant. Study of the interfacial behavior of fGOs at liquid−solid interface demonstrated that, after absorption, b-GO arranged vertically on the metal surface, forming dense, compact, and strong film, while e-GO aligned horizontally to form loosely assembled film, resulting in higher interfacial shear strength than that of b-GO. Our results indicate the possibilities for tuning the interfacial properties of GO at both liquid−liquid and liquid−solid interfaces, which may be promising in the potential applications in controlled drug delivery, surface protection, absorption and separation, lubrication, nanocomposite, and catalyst fields.

Arabinoxylan/graphene‐oxide/nHAp‐NPs/PVA bionano composite scaffolds for fractured bone healing

“…However, no diffraction peak for GO was observed in the spectra. The vanishing diffraction peak of GO may indicate successful chemical reactions among all components and stronger hydrogen bonding between GO with other polymeric components (Yang, Li, & Zeng, 2018). The characteristic diffraction peaks of ARX and PVA appears in the range of ∼2 θ = 20–30ᶿ.…”

Research and Application Progress Based on the Interfacial Properties of Graphene Oxide

“…Reproduced with permission. [ 38 ] Copyright 2018, American Chemistry Society. Interfacial properties of GO and b‐GO with different degree of oxidation: Interfacial tensions versus the concentrations of GO and b‐GO with different degrees of oxidation and TW20 at e) ethyl acetate‐water, f) toluene‐water, and g) n‐hexane‐water interfaces.…”

Effects of the surface polarity of nanomaterials on their interaction with complement protein gC1q

“…1A, gC1q protein is a compact, almost spherical heterotrimeric assembly consisting of 394 residues. As the O/C ratio of graphene oxide (GO) can be effectively adjusted in a range of $11-$51% in experiments, [41][42][43][44] two kinds of GO sheets with distinct O/C ratios, i.e., C 5 O 1 (OH) 1 ( Fig. 2A), and C 20 O 1 (OH) 1 (Fig.…”