https://www.bc.edu/content/dam/files/schools/cas_sites/physics/pdf/Ren/p85.pdf

Advances in the science and technology of carbon nanotubes and their composites: a review

Mechanical properties of nanocrystalline materials

Every few years, a new material with unique properties emerges and fascinates the scientific community, typical recent examples being high-temperature superconductors and carbon nanotubes. Graphene is the latest sensation with unusual properties, such as half-integer quantum Hall effect and ballistic electron transport. This two-dimensional material which is the parent of all graphitic carbon forms is strictly expected to comprise a single layer, but there is considerable interest in investigating two-layer and few-layer graphenes as well. Synthesis and characterization of graphenes pose challenges, but there has been considerable progress in the last year or so. Herein, we present the status of graphene research which includes aspects related to synthesis, characterization, structure, and properties.

Graphene: The New Two-Dimensional Nanomaterial

A detailed analysis of the thermal expansion mechanism of graphite oxide to produce functionalized graphene sheets is provided. Exfoliation takes place when the decomposition rate of the epoxy and hydroxyl sites of graphite oxide exceeds the diffusion rate of the evolved gases, thus yielding pressures that exceed the van der Waals forces holding the graphene sheets together. A comparison of the Arrhenius dependence of the reaction rate against the calculated diffusion coefficient based on Knudsen diffusion suggests a critical temperature of 550 °C which must be exceeded for exfoliation to occur. As a result of their wrinkled nature, the functionalized and defective graphene sheets do not collapse back to graphite oxide but are highly agglomerated. After dispersion by ultrasonication in appropriate solvents, statistical analysis by atomic force microscopy shows that 80% of the observed flakes are single sheets.

Single Sheet Functionalized Graphene by Oxidation and Thermal Expansion of Graphite

Graphene and related two-dimensional crystals and hybrid systems showcase several key properties that can address emerging energy needs, in particular for the ever growing market of portable and wearable energy conversion and storage devices. Graphene's flexibility, large surface area, and chemical stability, combined with its excellent electrical and thermal conductivity, make it promising as a catalyst in fuel and dye-sensitized solar cells. Chemically functionalized graphene can also improve storage and diffusion of ionic species and electric charge in batteries and supercapacitors. Two-dimensional crystals provide optoelectronic and photocatalytic properties complementing those of graphene, enabling the realization of ultrathin-film photovoltaic devices or systems for hydrogen production. Here, we review the use of graphene and related materials for energy conversion and storage, outlining the roadmap for future applications.

Graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage

https://hal.archives-ouvertes.fr/hal-01003709/document

Specific surface area of carbon nanotubes and bundles of carbon nanotubes

https://hal.archives-ouvertes.fr/hal-00938352/document

Carbon nanotube-metal-oxide nanocomposites: microstructure, electrical conductivity and mechanical properties

https://hal.archives-ouvertes.fr/hal-00957547/document

Carbon nanotubes in novel ceramic matrix nanocomposites

A carbon nanotube–Co–MgO composite powder is prepared by reducing a Mg0.9Co0.1O solid solution in H2–CH4 atmosphere. The oxide matrix and part of the Co catalyst are dissolved by acid treatment without damage to the nanotubes. More than 80% of the carbon nanotubes have either one or two walls. The diameters of the nanotubes are in the range 0.5–5 nm. The utilized method may be a real improvement in the low-cost, large-scale synthesis of single- and double-walled carbon nanotubes.

/pdf/synthesis-of-single-walled-carbon-nanotube-co-mgo-composite-1vld9l0e8c.pdf

Synthesis of single-walled carbon nanotube–Co–MgO composite powders and extraction of the nanotubes

https://hal.archives-ouvertes.fr/hal-00948432/document

Abel Rousset

Papers

Specific surface area of carbon nanotubes and bundles of carbon nanotubes

Carbon nanotube-metal-oxide nanocomposites: microstructure, electrical conductivity and mechanical properties

Carbon nanotubes in novel ceramic matrix nanocomposites

Synthesis of single-walled carbon nanotube–Co–MgO composite powders and extraction of the nanotubes

Synthesis of single-walled carbon nanotubes using binary (Fe, Co, Ni) alloy nanoparticles prepared in situ by the reduction of oxide solid solutions