Structure Of Graphene Materials Research Articles

Graphene-based nanocomposites and their fabrication, mechanical properties and applications

Graphene, the thinnest two-dimensional atomic material, has immerged as a revolutionary material and sparked a flurry of research and innovation owing to its outstanding mechanical, electrical, optical and thermal properties as well as high specific surface area. Graphene-based materials and their composites possess promising applications in a wide range of fields such as sensors, actuators, electronics, biomedical aids and membranes. In this review paper, a critical and comprehensive review has been carried out on the synthesis process and mechanical properties of graphene and graphene-based nanocomposites. Firstly, the concept and structure of graphene materials are discussed then different synthesis techniques and their advantages and limitations have been reviewed. The addition of graphene and its derivatives in producing different polymer and metal-based nanocomposite as well as fabricating hybrid nanocomposite has been thoroughly reviewed. Almost all the papers show that the presence of graphene even at very low loadings can provide significant improvement to the final material. Besides, other parameters that affect the nanocomposite are thoroughly reviewed. Furthermore, the perspective application of graphene materials and its nanocomposite in different promising fields has been discussed.

Hydrophilic graphene aerogel anodes enhance the performance of microbial electrochemical systems

The hydrophilic three-dimensional (3D) structure of graphene materials was produced with reducing agent-ethylene glycol through hydrothermal reduction. Numerous microorganisms with diverse community structure were established in anode surface, as the hydrophilicity of the graphene anode increased; more populations of Proteobacteria and Firmicutes families were identified in a higher hydrophilic anode. In addition, the start-up time of a microbial fuel cell (MFC) equipped with hydrophilic 3D graphene anode was only 43 h, which is much shorter than traditional 3D graphene-based anode systems. The most hydrophilic anode exhibited the maximal power density of 583.8 W m−3, 5 times larger than the least hydrophilic one. The content of oxygen in graphene materials improving hydrophilicity would play an important role in enhancing power density. This study proves that hydrophilic 3D graphene materials as the anode can improve MFC performance and start-up time.

Main structural features of graphene materials controlling the transport properties of epoxy resin-based composites

Graphene materials (GMs) are deeply studied as nanoreinforcements of polymer matrices, especially for epoxy matrices. Here, we analyze the effect of GMs on the transport properties of a poly(bisphenol A-co-epichlorohydrin) resin. In particular, we focus on the effect of the morphology, chemical composition and structure of different GMs obtained by varying the reduction temperature of the thermal/exfoliation treatment of graphite oxide synthesized by a modified Hummers method. The dispersion degree of the GMs was studied by microscopy techniques, showing a strong dependence on the specific surface area and chemical composition of the graphene material. The transport properties imposed different requirements on GMs. The thermal conductivity benefited from a high aromatic restoration. Meanwhile, the electrical conductivity required the right balance of filler/matrix interaction and aromatic restoration.