Synthesis and in-situ oxygen functionalization of deposited graphene nanoflakes for nanofluid generation

Legrand, Ulrich; Gonzalez, N.-Y. Mendoza; Pascone, Pierre-Alexandre; Meunier, Jean‐Luc; Berk, Dimitrios

doi:10.1016/j.carbon.2016.02.043

Cited by 25 publications

(61 citation statements)

References 24 publications

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“…The gas feed of methane and nitrogen is changed to air for the second stage. The oxygen in the air then forms an active species and interacts with the GNF surface to produce a tunable quantity of hydrophilic groups . Both the hydrophobic and hydrophilic GNFs are between 5 and 20 atomic layers thick, 10 layers on average, and have in-plane dimensions of roughly 100 × 100 nm 2 .…”

Section: Methodsmentioning

confidence: 99%

“…An example of a hydrate-promoting nanomaterial is graphene nanoflakes (GNFs). These carbon nanoparticles have been found to increase the yields of methane hydrates and several other gas hydrate compounds. − However, GNFs are naturally hydrophobic and thus require the addition of surfactants or chemical treatments to improve their stability in solution and avoid settling or agglomeration. , Recent advancements have led to the addition of oxygen-containing groups on GNF powder surfaces through a thermal plasma decomposition and chemical functionalization process. The addition of a specific amount of oxygen-containing groups, typically in the order of 14 at.…”

Section: Introductionmentioning

confidence: 99%

“…The addition of a specific amount of oxygen-containing groups, typically in the order of 14 at. % O, to the GNF particles results in a stable nanofluid . In fact, aqueous GNFs are able to maintain their dispersion for several months owing to these oxygenated functionalities such as hydroxyl, carboxyl, and other oxide groups .…”

Section: Introductionmentioning

confidence: 99%

“…% O, to the GNF particles results in a stable nanofluid . In fact, aqueous GNFs are able to maintain their dispersion for several months owing to these oxygenated functionalities such as hydroxyl, carboxyl, and other oxide groups . Alongside as-produced GNF samples, functionalized GNFs were used in a study that investigated their effects on the growth rates of methane hydrates .…”

Section: Introductionmentioning

confidence: 99%

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Effects of Hydrophobic and Hydrophilic Graphene Nanoflakes on Methane Dissolution Rates in Water under Vapor–Liquid–Hydrate Equilibrium Conditions

McElligott

Meunier

Servio

2021

Ind. Eng. Chem. Res.

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Several industries have steadily gained interest in gas hydrate technologies for their potential use in natural gas transport and storage applications. Additives which optimize the efficiencies of these technologies, particularly nanoparticles, have lately been subject to an increasing investigative focus. Graphene nanoflakes (GNFs) have previously been proven to enhance hydrate systems, particularly methane hydrate systems. In this study, the dissolution rates of methane and molar saturation values were measured in nanofluids containing both hydrophobic (as-produced) and hydrophilic (plasma-functionalized) GNFs at 2 °C and 3146 kPa. For both types of GNFs, the effect of loading in the aqueous phase was equally determined. Dissolution rate enhancement was limited at low concentrations of around 0.5 ppm for hydrophobic GNFs due to small-scale agglomeration while significantly increasing dissolution kinetics by about 18.84% at concentrations of 5 ppm. The performance eventually decreased at higher concentrations (10 ppm) due to large-scale agglomeration. Hydrophilic GNFs, which exhibited no agglomeration, enhanced dissolution rates further with each successive loading until a 44.45% plateau at 10 ppm. This plateau may have been a limit of the system or a result of mean free path limitations. Either type of GNFs nearly triples the dissolution rates of methane investigated in previous studies on multi-walled carbon nanotubes due to their higher specific surface area.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Hydrophobic and Hydrophilic Graphene Nanoflakes on Methane Dissolution Rates in Water under Vapor–Liquid–Hydrate Equilibrium Conditions

McElligott

Meunier

Servio

2021

Ind. Eng. Chem. Res.

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“…Frequently, carbon nanotubes are doped, functionalized, or conjugated with atoms, molecules and compounds in order to improve their properties [Muhulet 2018, Naqvi 2020, Merum 2017, notably their chemical reactivity due to their intrinsically inert surface. Grafting of oxygen groups at the surface of carbon nanomaterials is one of the most used functionalization for carbon materials, including carbon nanotubes [Tulli 2017, Adil 2020, Legrand 2016, Zuaznabar-Gardona 2020. Oxygen groups grafted to the surface of carbon nanotubes affects their chemical and electronic properties, for example increasing surface chemical reactivity, decreasing hydrophobicity allowing solubilization in aqueous media, and transforming metallic carbon nanotubes to semiconducting [Malik 2016, Barinov 2009.…”

Section: Introductionmentioning

confidence: 99%

Thermal stability of oxygen functionalization in v-CNTs by low kinetic energy ion irradiation

Acosta

Sierra-Castillo

Colomer

et al. 2021

Vacuum

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Vertically aligned multiwalled carbon nanotubes synthetized by thermal catalytic chemical vapor deposition are irradiated with low kinetic energy oxygen ions to graft oxygen functional groups at their surface. Subsequently, the thermal stability of these functional groups is investigated by heating the sample progressively to 200, 300, 400 and 500 ºC. X-Ray photoelectron spectroscopy (XPS) is used to analyze the atomic concentration and chemical configuration of the sample at each stage. Scanning and transmission electron microscopies are used to observe the morphology of the nanotubes after the thermal treatment. The solvent-free functionalization is carried out in 10 minutes reaching an oxygen atomic concentration of 17.2 at.%, with no impurities introduced. At the end of the thermal treatment, the relative oxygen content drops to 5.6 at.%. XPS analysis indicates four oxygen groups are produced by the ion irradiation: epoxide, hydroxyl, carbonyl and carboxyl groups, with the epoxides the least stable and the carbonyls the most stable.Combining low kinetic energy ion-implantation with a short post-anneal is shown to be an effective route to simultaneously control both sample oxygen content and the ratio of different oxygenated functional groups.

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Elastomeric and Conductive Nerve Conduits From Poly(Glycerol‐Sebacate)/Carbon Nanofibers (PGS/CNFs)

Topuz,

Gokcen,

Aydin

2024

J Biomedical Materials Res

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Many patients suffer from peripheral nerve injury, which can impair their quality of life. Restoring nerve tissue is difficult due to the low ability of nerves to regenerate. Nerve conduits are designed to help peripheral nerve regeneration by providing a scaffold that can match the tissue characteristics, facilitate cellular activities, and be easily implanted. In order to provide a nerve conduit having scaffolding properties, conductance cytocompatibility, we have investigated the potential of channeled structures made of poly (glycerol‐sebacate) (PGS) elastomer containing carbon nanofibers (CNFs) in the regeneration of nerve tissue. The first step was to synthesize PGS elastomer and tune its properties to match the nerve tissue. Then, a carbon dioxide laser was used to create micro channels on the elastomer surface for guiding nerve cells. The PGS elastomer was blended with carbon nanofiber (CNF), which was functionalized to bond with the elastomer, to form a conductive structure. The constructs were investigated in terms of cell behavior using PC12 and S42 cell lines. A statistically significant increase in cell proliferation was observed in both cell lines. It was found that the cells began to grow along the canal in places. In terms of elasticity, conductance and cell response, these constructs may be a potential candidate for nerve tissue engineering.

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Synthesis and in-situ oxygen functionalization of deposited graphene nanoflakes for nanofluid generation

Cited by 25 publications

References 24 publications

Effects of Hydrophobic and Hydrophilic Graphene Nanoflakes on Methane Dissolution Rates in Water under Vapor–Liquid–Hydrate Equilibrium Conditions

Effects of Hydrophobic and Hydrophilic Graphene Nanoflakes on Methane Dissolution Rates in Water under Vapor–Liquid–Hydrate Equilibrium Conditions

Thermal stability of oxygen functionalization in v-CNTs by low kinetic energy ion irradiation

Elastomeric and Conductive Nerve Conduits From Poly(Glycerol‐Sebacate)/Carbon Nanofibers (PGS/CNFs)

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