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

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

“…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 .…”

“…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.…”

“…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 .…”

“…% 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 .…”

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

“…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.…”