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Graphical abstract Highlights • A solvent-free urea melt synthesis to modify fluorinated graphene. • FGO functionalization to produce hydrophilic graphene with amino-groups. • Modified graphene sheets functionalized with good water-solubility. • Broaden the application in aqueous environments of fluorinated graphene. Abstract Fluorinated graphene has attracted a lot of scientific interest due to its excellent properties and novel structure, but its applications are still challenging because of its poor dispersion and severe agglomeration. We propose a solvent-free synthesis of novel modified fluorinated graphene oxide (mFGO) with good water compatibility with. We used graphene oxide (GO) prepared by Hummers method as a precursor. The oxygen-containing functional groups on GO were hydrothermally reacted to convert GO into FGO. Then, the amino functional groups were introduced to the FGO surface by a solvent-free urea modification reaction. This method produced graphene modified with both fluorine and amino groups in high yield. It shows great potential in introducing mFGO as a reactive modifier in waterborne epoxy materials for a variety of industrial applications. [ABSTRACT FROM AUTHOR]

• The CF 0.75 cathode has successfully modified by an ultrathin carbon layer (CF 0.75 @C). • The modified CF 0.75 @C has a high degree of disorganization. • The modified CF 0.75 @C provides additional paths for electronic transmission. • The Li/CF x primary batteries using of CF 0.75 @C cathode achieve better performance. To improve the electrochemical performance of lithium/fluorinated graphite (Li/CF x) primary batteries, the surface of fluorinated graphite cathode is modified with ultrathin carbon layer (CF 0.75 @C) by hydrothermal method. The electrochemical performance and voltage delay of the CF 0.75 @C are significantly improved compared to the pristine CF 0.75 , due to the carbon coating reducing charge transfer resistance and providing more electrons/ions transport paths. As a result, the assembled batteries can discharge at a high rate of 6C and exhibit a specific capacity of 327 mAh/g, corresponding to a high energy density of 625 Wh kg−1. In addition, the optimized batteries exhibit excellent high and low temperature performances (−20 °C ∼ 80 °C), which can be used regularly under harsh conditions. Significantly, this research provides a novel idea to achieve Li/CF x primary batteries with high discharge speed, low voltage delays and a wide temperature range. [ABSTRACT FROM AUTHOR]

Fluorinated graphene (fluorographene) has attracted increasing attention due to the combination of unique properties of graphite fluoride and graphene. Development of fluorographene-based technology relies on the availability of fluorographene nanosheets in large quantities. Here, a melamine assisted solid exfoliation method is developed for the synthesis of fluorographene nanosheets. Under optimized solid ball milling condition, micrometer-sized ultrathin (less than 2 nm in thickness) fluorographene nanosheets can be exfoliated from graphite fluoride in the presence of melamine. The melamine assisted solid ball milling method is facile and highly efficient, and holds great promise for the large-scale preparation of few-layered fluorographene nanosheets. [ABSTRACT FROM AUTHOR]

A facile but efficient method has been developed to prepare graphene nanosheets (GNS) by reacting graphite fluoride with molten hydroxides at low temperature. Through the reaction, the resultant product shows a good dispersion in ethanol solution to self-exfoliate into GNS. The morphology and structure of GNS were characterized by microscopic and spectroscopic techniques, respectively. The results indicate that the GNS exhibit wrinkled structure with small sheet thickness and contain low quantities of oxygen functional groups arising from the displacement of fluorine atoms by hydroxyl radicals. This study provides a cost-effective route to large-scale production of soluble GNS for many potential applications. [ABSTRACT FROM AUTHOR]

We investigate the effect of cell culture conditions, using functionalized graphene sheets with oxygen (-O) or fluorine (-F) as growth surfaces, on the human nerve cell line (SH-SY5Y). We applied the fluorescence microscopy of cells stained with Hochest 33342, Calcein AM, and MTT assay to evaluate cell viability and morphology. The effect of the graphene on the cells in culture was dependent on the atomic state of the graphene sheet. SH-SY5Y cells exhibited approximately 138% viability (MTT assay) on the oxygenated graphene sheets and 50% viability on the fluorinated graphene sheets, as compared to the data from culturing on pristine graphene. [ABSTRACT FROM AUTHOR]