Industrial Carbon and Graphite Materials. Группа авторов
Description
GLASS‐LIKE CARBON is an AGRANULAR NON‐GRAPHITIZABLE CARBON with a very high isotropy of its structural and physical properties and with very low permeability for liquids and gases. The original surfaces and the fracture surfaces have a pseudo‐glassy appearance.
See: AGRANULAR CARBON, NON‐GRAPHITIZABLE CARBON.
Notes
The often used synonyms “Glassy Carbon” and “Vitreous Carbon” have been introduced as trademarks and should not be used as terms. From a scientific viewpoint, all synonymous terms suggest a similarity with the structure of silicate glasses, which does not exist in GLASS‐LIKE CARBON, except for the pseudo‐glassy appearance of the surface.
GLASS‐LIKE CARBON cannot be described as AMORPHOUS CARBON because it consists of two‐dimensional structural elements and does not exhibit “dangling” bonds.
See: AMORPHOUS CARBON.
Granular Carbon
Description
The term GRANULAR CARBON is equivalent to coarse PARTICULATE CARBON. This is a CARBON MATERIAL consisting of separate particles or grains that are monolithic, on the average larger than about 100 μm, but smaller than about 1 cm.
See: CARBON MATERIAL, PARTICULATE CARBON.
Notes
Although limits of size cannot be exactly defined, COKE grains obtained by grinding belong to coarse PARTICULATE CARBON for grain sizes above approximately 100 μm or to fine PARTICULATE CARBON for grain sizes below approximately 100 μm. COLLOIDAL GRAPHITE obtained by grinding of NATURAL GRAPHITE is a typical extra fine PARTICULATE CARBON. Industrial CARBON MATERIALS (such as electrodes) are made with FILLERS composed of coarse PARTICULATE CARBON (COKE grains) and fine PARTICULATE CARBON (flour) and sometimes even COLLOIDAL CARBON (CARBON BLACKS or SOOT). They are therefore polygranular materials.
See: CARBON BLACK, CARBON MATERIAL, COKE, COLLOIDAL CARBON, FILLER, NATURAL GRAPHITE, PARTICULATE CARBON, POLYGRANULAR CARBON, POLYGRANULAR GRAPHITE, SOOT.
Graphene Layer
Description
GRAPHENE is a single carbon layer of the GRAPHITE structure, describing its nature by analogy to a polycyclic aromatic hydrocarbon of quasi infinite size.
See: GRAPHITE.
Notes
Previously, descriptions such as graphite layers, carbon layers, or carbon sheets have been used for the term GRAPHENE.
Because GRAPHITE designates that modification of the chemical element CARBON, in which planar sheets of carbon atoms, each atom bound to three neighbors in a honeycomb‐like structure, are stacked in a three‐dimensional regular order, it is not correct to use for a single layer a term that includes the term GRAPHITE, which would imply a three‐dimensional structure. The term GRAPHENE should be used only when the reactions, structural relations, or other properties of individual layers are discussed.
See: CARBON, GRAPHITE.
Graphite
Description
GRAPHITE is an allotropic form of the element carbon consisting of layers of hexagonally arranged carbon atoms in a planar condensed ring system (GRAPHENE LAYERS). The layers are stacked parallel to each other in a three‐dimensional crystalline long‐range order. There are two allotropic forms with different stacking arrangements, hexagonal and rhombohedral. The chemical bonds within the layers are covalent with sp2 hybridization and with a C–C distance of 141.7 pm. The weak bonds between the layers are metallic with a strength comparable to VAN DER WAALS bonding only.
See: CARBON, HEXAGONAL GRAPHITE, RHOMBOHEDRAL GRAPHITE.
Notes
The term GRAPHITE is also used often but incorrectly to describe GRAPHITE MATERIALS, i.e. materials consisting of GRAPHITIC CARBON made from CARBON MATERIALS by processing to temperatures greater than 2500 K, even though no perfect graphite structure is present.
See: CARBON MATERIAL, GRAPHITIC CARBON, GRAPHITE MATERIAL.
Graphite Electrode
Description
See: CARBON ELECTRODE.
Graphite Fibers
Description
GRAPHITE FIBERS are CARBON FIBERS consisting mostly of SYNTHETIC GRAPHITE for which three‐dimensional crystalline order is confirmed by X‐ray diffraction.
See: CARBON FIBERS, SYNTHETIC GRAPHITE.
Notes
GRAPHITE FIBERS can be obtained by GRAPHITIZATION HEAT TREATMENT of CARBON FIBERS if these consist mostly of GRAPHITIZABLE CARBON. If the h,k,l diffraction lines are difficult to recognize because they are of minor intensity, the mean interlayer spacing c/2 can be used as indication for the presence of a graphitic structure. The c/2 value of 0.34 nm is generally considered as an upper limit for SYNTHETIC GRAPHITE.
See: CARBON FIBERS, GRAPHITIZABLE CARBON, GRAPHITIZATION HEAT TREATMENT, SYNTHETIC GRAPHITE.
Graphite Material
Description
GRAPHITE MATERIAL is a material consisting essentially of GRAPHITIC CARBON.
See: GRAPHITE, GRAPHITIC CARBON.
Notes
The use of the term GRAPHITE as a short term for material consisting of GRAPHITIC CARBON is incorrect. The term GRAPHITE can only be used in combination with other nouns or clarifying adjectives for special types of GRAPHITE MATERIALS (GRAPHITE ELECTRODES, NATURAL GRAPHITE, and others). The use of the term GRAPHITE without a noun or clarifying adjective should be restricted to the allotropic form of the element CARBON.
See: CARBON, GRAPHITE, GRAPHITE ELECTRODE, GRAPHITIC CARBON, NATURAL GRAPHITE.
Graphite Whiskers
Description
GRAPHITE WHISKERS consists of thin, approximately cylindrical filaments in which GRAPHENE LAYERS are arranged in a scroll‐like manner. There is, at least in part, a regular stacking of the layers as in the GRAPHITE lattice, giving rise to h,k,l X‐ray reflections. The physical properties of GRAPHITE WISKERS approach,