Liquid interface evolution of polyhedral-like graphene

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.Centrifugation of the graphene oxide mediated Pickering emulsion results in transforming spheroidal toluene droplets into irregular polyhedral shapes, which can be preserved into a solid three-dimensional polyhedral-like graphene oxide network featuring facets and sharp edges, using a freeze-drying strategy

Amphiphilic graphene oxide stabilisation of hexagonal BN and MoS2 sheets

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.A simple and scalable method has been developed for directly forming water-dispersible van der Waals solids involving mixing aqueous solution of graphene oxide (GO) with hexagonal boron nitride (BN) or molybdenum disulphide (MoS2) in N-methylpyrrolidone. The GO acts as an amphiphile in stabilising the colloidal solutions of the heterolaminar material in water

Unravelling the structure of the C60 and p-But-calix[8]arene complex

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.The structure of the C60 and p-But-calix[8]arene complex has been reinvestigated, showing an unprecedented continuous layered tetragonal array of fullerenes encapsulated by calixarenes. Electron diffraction data revealed the tetragonal symmetry, with a stepped structure observed by AFM and SEM, and the thickness of the basal plane was measured by XRD, as 2 nm. The molecular simulated arrangement of fullerenes accounts for the ability to take up to ca. 11% of fullerenes C70 in place of the smaller fullerene

Plasma enhanced vortex fluidic device manipulation of graphene oxide

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.A vortex fluid device (VFD) with non-thermal plasma liquid processing within dynamic thin films has been developed. This plasma–liquid microfluidic platform facilitates chemical processing which is demonstrated through the manipulation of the morphology and chemical character of colloidal graphene oxide in water

Sub-micron moulding topological mass transport regimes in angled vortex fluidic flow

Shear stress in dynamic thin films, as in vortex fluidics, can be harnessed for generating non-equilibrium conditions, but the nature of the fluid flow is not understood. A rapidly rotating inclined tube in the vortex fluidic device (VFD) imparts shear stress (mechanical energy) into a thin film of liquid, depending on the physical characteristics of the liquid and rotational speed,ω, tilt angle,θ, and diameter of the tube. Through understanding that the fluid exhibits resonance behaviours from the confining boundaries of the glass surface and the meniscus that determines the liquid film thickness, we have established specific topological mass transport regimes. These topologies have been established through materials processing, as spinning top flow normal to the surface of the tube, double-helical flow across the thin film, and spicular flow, a transitional region where both effects contribute. The manifestation of mass transport patterns within the film have been observed by monitoring the mixing time, temperature profile, and film thickness against increasing rotational speed,ω. In addition, these flow patterns have unique signatures that enable the morphology of nanomaterials processed in the VFD to be predicted, for example in reversible scrolling and crumbling graphene oxide sheets. Shear-stress induced recrystallisation, crystallisation and polymerisation, at different rotational speeds, provide moulds of high-shear topologies, as ‘positive’ and ‘negative’ spicular flow behaviour. ‘Molecular drilling’ of holes in a thin film of polysulfone demonstrate spatial arrangement of double-helices. The grand sum of the different behavioural regimes is a general fluid flow model that accounts for all processing in the VFD at an optimal tilt angle of 45°, and provides a new concept in the fabrication of novel nanomaterials and controlling the organisation of matter

Association of Genetic Variants of Melatonin Receptor 1B with Gestational Plasma Glucose Level and Risk of Glucose Intolerance in Pregnant Chinese Women

BACKGROUND: This study aimed to explore the association of MTNR1B genetic variants with gestational plasma glucose homeostasis in pregnant Chinese women. METHODS: A total of 1,985 pregnant Han Chinese women were recruited and evaluated for gestational glucose tolerance status with a two-step approach. The four MTNR1B variants rs10830963, rs1387153, rs1447352, and rs2166706 which had been reported to associate with glucose levels in general non-pregnant populations, were genotyped in these women. Using an additive model adjusted for age and body mass index (BMI), association of these variants with gestational fasting and postprandial plasma glucose (FPG and PPG) levels were analyzed by multiple linear regression; relative risk of developing gestational glucose intolerance was calculated by logistic regression. Hardy-Weinberg Equilibrium was tested by Chi-square and linkage disequilibrium (LD) between these variants was estimated by measures of D' and r(2). RESULTS: In the pregnant Chinese women, the MTNR1B variant rs10830963, rs1387153, rs2166706 and rs1447352 were shown to be associated with the increased 1 hour PPG level (p=8.04 × 10(-10), 5.49 × 10(-6), 1.89 × 10(-5) and 0.02, respectively). The alleles were also shown to be associated with gestational glucose intolerance with odds ratios (OR) of 1.64 (p=8.03 × 10(-11)), 1.43 (p=1.94 × 10(-6)), 1.38 (p=1.63 × 10(-5)) and 1.24 (p=0.007), respectively. MTNR1B rs1387153, rs2166706 were shown to be associated with gestational FPG levels (p=0.04). Our data also suggested that, the LD pattern of these variants in the studied women conformed to that in the general populations: rs1387153 and rs2166706 were in high LD, they linked moderately with rs10830963, but might not linked with rs1447352;rs10830963 might not link with rs1447352, either. In addition, the MTNR1B variants were not found to be associated with any other traits tested. CONCLUSIONS: The MTNR1B is likely to be involved in the regulation of glucose homeostasis during pregnancy

Preparation and Applications of Fluorinated Graphenes

International audienceThe present review focuses on the numerous routes for the preparation of fluorinated graphene (FG) according to the starting materials. Two strategies are considered: (i) addition of fluorine atoms on graphenes of various nature and quality and (ii) exfoliation of graphite fluoride. Chemical bonding in fluorinated graphene, related properties and a selection of applications for lubrication, energy storage, and gas sensing will then be discussed

Liquid-Phase Exfoliation of Poly(Dicarbon Monofluoride) (C2F)n

Fluorinated single-layer diamond (“F-diamond”) is a new form of two-dimensional carbon allotrope. Herein, poly(dicarbon monofluoride) (C2F)n that is essentially made of stacked layers of “F-diamane” has been synthesized and exfoliated in a variety of solvents to yield well-dispersed ultrathin sheets. Microscopic and spectroscopic analyses revealed that the exfoliated sheets retained the “F-diamane”-like structure. The experimental results are supported by the density functional theory (DFT) calculations

Liquid-phase exfoliation of F-diamane-like nanosheets

International audienceFluorinated single-layer diamond (“F-diamond”) is a new form of two-dimensional (2D) carbon allotrope. Herein, poly(dicarbon monofluoride) (C2F)n which is essentially made of stacked layers of “F-diamane” has been synthesized and exfoliated in a variety of solvents to yield well-dispersed ultrathin sheets. Microscopic and spectroscopic analyses revealed that the exfoliated nanosheets retained the “F-diamane”-like structure. The experimental results are also supported by density functional theory (DFT) calculations

F-diamane-like nanosheets from expanded fluorinated graphite

International audienceUltrathin diamond (diamane)-like films or nanosheets have recently been experimentally obtained through chemically induced phase transition (e.g., fluorination) of bilayer graphene films or graphite flakes. To fully exploit the properties of diamane, further advances in the synthesis methods for its large-scale production are required. Herein, we report a new route for the efficient and high-yield production of fluorinated diamane (F-diamane)-like nanosheets. This is achieved by direct fluorination of expandable graphite or thermally expanded graphite with molecular fluorine to form stage-2 graphite fluoride (C2F)n made of stacked layers of F-diamane. Subsequently, mild sonication is implemented to exfoliate the layers into F-diamane-like nanosheets of hundreds of nanometers to a few micrometers in lateral size, with a thickness of mostly < 10 nm