Industrial Carbon and Graphite Materials. Группа авторов
ACTIVATED CARBON, CARBON FIBERS, CARBON MATERIAL, CHAR, FIBROUS ACTIVATED CARBON.
Notes
For definition of micropores see IUPAC Manual of Symbols and Terminology, Appendix 2, Pt. 1, Colloid and Surface Chemistry [6].
The surface areas determined by the Brunauer–Emmett–Teller (BET) method are apparent surface areas only since the BET adsorption equation is, in principle, not valid when micropore filling occurs. The determination of the true surface area in the micropores depends on the method used for the evaluation of the adsorption isotherms and on the model used for the shape of the micropores (cylindrical, slit shape, or other).
MPP‐Based Carbon Fibers
Description
See: MESOPHASE PITCH‐BASED CARBON FIBERS.
Natural Graphite
Description
NATURAL GRAPHITE is a mineral found in nature. It consists of GRAPHITIC CARBON regardless of its crystalline perfection.
See: GRAPHITIC CARBON.
Notes
Some NATURAL GRAPHITES, often in the form of large flakes, show very high crystalline perfection. Occasionally, they occur as single crystals of GRAPHITE. The use of the term NATURAL GRAPHITE as a synonym for the term “graphite single crystal” is incorrect and should be avoided. Varieties of NATURAL GRAPHITE with lower structural perfection are classified as “microcrystalline NATURAL GRAPHITE.” Commercial NATURAL GRAPHITE is often contaminated with other minerals, e.g. silicates, and may contain RHOMBOHEDRAL GRAPHITE due to intensive milling.
See: GRAPHITE, RHOBOHEDRAL GRAPHITE.
Needle Coke
Description
NEEDLE COKE is the commonly used term for a special type of COKE with extremely high graphitizability resulting from a strong preferred parallel orientation of its turbostratic layer structure and a particular physical shape of the grains.
See: COKE.
Notes
NEEDLE COKE is derived mainly from clean (i.e. lacking hetero atoms and solids) and highly aromatic (i.e. several condensed rings per cluster) feedstocks with a very low concentration of insolubles. Upon solidification a material with distinctive streaked or flow‐like macroscopic appearance is produced. Upon grinding the COKE breaks up first into macroscopic needles and then, after further grinding, into microplatelets. Sometimes the word “acicular” is used as a synonym for needlelike.
See: COKE, DELAYED COKING PROCESS.
Non‐graphitic Carbon
Description
NON‐GRAPHITIC CARBONS are all varieties of solids consisting mainly of the element CARBON with two‐dimensional long‐range order of the carbon atoms in planar hexagonal networks, but without any measurable crystallographic order in the third direction (c direction) apart from more or less parallel stacking.
See: AMORPHOUS CARBON, CARBON.
Notes
Some varieties of NON‐GRAPHITIC CARBON convert on heat treatment to GRAPHITIC CARBON (GRAPHITIZABLE CARBON), but some others do not (NON‐GRAPHITIZABLE CARBON).
See: GRAPHITIC CARBON, GRAPHITIZABLE CARBON, NON‐GRAPHITIC CARBON, NON‐GRAPHITIZABLE CARBON.
Non‐graphitizable Carbon
Description
NON‐GRAPHITIZABLE CARBON is a NON‐GRAPHITIC CARBON that cannot be transformed into GRAPHITIC CARBON solely by high‐temperature treatment up to 3300 K under atmospheric pressure or lower pressure.
See: GRAPHITIC CARBON, GRAPHITIZATION HEAT TREATMENT, NON‐GRAPHITIC CARBON.
Notes
The term NON‐GRAPHITIZABLE is limited to the result of heat treatment without additional influence of foreign matter or neutron radiation. NON‐GRAPHITIZABLE CARBON can be transformed into GRAPHITIC CARBON by a high‐temperature process via intermediate dissolution in foreign matter and precipitation under high pressure or by radiation damage.
See: GRAPHITIC CARBON.
Nuclear Graphite
Description
NUCLEAR GRAPHITE is a POLYGRANULAR GRAPHITE material for use in nuclear reactor cores consisting of GRAPHITIC CARBON of very high chemical purity. High purity is needed to avoid absorption of low‐energy neutrons and the production of undesirable radioactive species.
See: GRAPHITE MATERIAL, GRAPHITIC CARBON, POLYGRANULAR GRAPHITE.
Notes
Apart from the absence of neutron‐absorbing impurities, modern reactor graphites are also characterized by a high degree of GRAPHITIZATION and no preferred bulk orientation. Such properties increase the dimensional stability of the NUCLEAR GRAPHITE at high temperatures and in a high flux of neutrons. The term NUCLEAR GRAPHITE is often, but incorrectly, used for any GRAPHITE MATERIAL in a nuclear reactor, even if it serves only for structural purposes.
See: GRAPHITE MATERIAL, GRAPHITIZATION.
Pan‐Based Carbon Fibers
Description
PAN‐BASED CARBON FIBERS are CARBON FIBERS obtained from polyacrylonitrile (PAN) precursor fibers by STABILIZATION TREATMENT, CARBONIZATION, and final heat treatment.
See: CARBON FIBERS, CARBONIZATION, STABILIZATION TREATMENT.
Particulate Carbon
Description
PARTICULATE CARBON is a CARBON MATERIAL consisting of separated monolithic particles.
See: CARBON MATERIAL.
Notes
Distinctions should be made between coarse PARTICULATE CARBON or GRANULAR CARBON (larger than about 100 μm, but smaller than about 1 cm in average size), fine PARTICULATE CARBON or powder or flour (between 1 and 100 μm in average size), and COLLOIDAL CARBON (below approximately 1 μm in size in at least one direction), e.g. CARBON BLACKS and COLLOIDAL CARBON.
See: CARBON BLACK, COLLOIDAL CARBON, GRANULAR CARBON, PARTICULATE CARBON.
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