CARBON with visible pores is still an AGRANULAR CARBON. The same is true, for instance, for PYROLYTIC CARBON with preferred orientation, such as conical or lamellar structures, visible in optical microscopy with polarized light. The use of the term AGRANULAR CARBON is not restricted to bulk materials of a minimum size. Only PARTICULATE CARBON should be excluded even if the isolated particles exhibit a homogeneous microstructure.
See: GLASS‐LIKE CARBON, PARTICULATE CARBON, PYROLYTIC CARBON.
Amorphous Carbon
Description
AMORPHOUS CARBON is a CARBON MATERIAL without long‐range crystalline order. Short‐range order exists, but with deviations of the interatomic distances and/or interbonding angles with respect to the graphite lattice as well as to the diamond lattice.
See: CARBON MATERIAL, DIAMOND‐LIKE CARBON.
Notes
The term AMORPHOUS CARBON is restricted to the description of CARBON MATERIALS with localized π electrons as described by Anderson [4]. Deviations in the C–C distances greater than 5% (i.e. ±Δx/xo > 0.05, where xo is the interatomic distance in the crystalline lattice for the sp2 as well as for the sp3 configuration) occur in such materials, as well as deviations in the bond angles because of the presence of “dangling bonds.”
The above description of AMORPHOUS CARBON is not applicable to CARBON MATERIALS with two‐dimensional structural elements present in all pyrolysis residues of carbon compounds as polyaromatic layers with a nearly ideal interatomic distance of a = 142 pm and an extension greater than 1000 pm.
See: CARBON MATERIAL.
Artificial Graphite
Description
The term ARTIFICIAL GRAPHITE is often used in place of SYNTHETIC GRAPHITE.
See: SYNTHETIC GRAPHITE.
Notes
This term is not recommended.
Baking
Description
The process in which the carbonaceous BINDER, usually COAL‐TAR PITCH or PETROLEUM PITCH, as part of a shaped CARBON MIX is converted to CARBON yielding a rigid carbon body by the slow application of heat. The process can take as little as 14 days in coarse‐grained, electrothermic grades (low binder level) and as long as 36 days in ultrafine‐grained, specialty grades (high binder level). The final baking temperature can be in the range of 1100–1500 K, depending on the grade.
See: BINDER, CARBON, CARBON MIX, COAL‐TAR PITCH, PETROLEUM PITCH.
Binder
Description
A BINDER is usually a COAL‐TAR PITCH or PETROLEUM PITCH (but may include thermosetting resins or MESOPHASE PITCH powders) that, when mixed with a BINDER COKE or a FILLER, constitutes a CARBON MIX. This is used in preparation of the formation of shaped green bodies and subsequently CARBON ARTIFACTS.
See: BINDER COKE, CARBON ARTIFACT, CARBON MIX, COAL‐TAR PITCH, FILLER, MESOPHASE PITCH, PETROLEUM PITCH, PITCH.
Binder Coke
Description
BINDER COKE is a constituent of a carbon (or ceramic) artifact resulting from CAROBONIZATION of the binder during baking.
See: CARBONIZATION.
Notes
PITCHES are mainly used as binders, i.e. as precursors for BINDER COKES, but the term BINDER should include any carbonaceous binder material, for example, thermosetting resins such as poly(furfuryl) alcohol or phenolics and similar compounds, which may form a CHAR during CARBONIZATION.
See: BINDER, CARBONIZATION, CHAR, PITCH.
Brooks and Taylor Structure in the Carbonaceous Mesophase
Description
The BROOKS AND TAYLOR STRUCTURE IN THE CARBONACEOUS MESOPHASE refers to the structure of the anisotropic spheres that precipitate from isotropic PITCH during pyrolysis. The structure of the spheres consists of a lamellar arrangement of aromatic molecules in parallel layers that are perpendicular to the polar axis of the sphere and are perpendicular to the mesophase–isotropic phase interface.
See: PITCH.
Notes
The term BROOKS AND TAYLOR STRUCTURE is recommended to describe the particular lamellar morphology of the spherules most commonly precipitated from pyrolyzed PITCH. The term honors the workers who first recognized the significance of CARBONACEOUS MESOPHASE to carbon science and technology and who first defined this spherical morphology. The term BROOKS AND TAYLOR STRUCTURE does not cover all structures found in spherical mesophase, because other lamellar arrangements have been observed.
See: CARBONACEOUS MESOPHASE, PITCH.
Bulk Mesophase
Description
BULK MESOPHASE is a continuous anisotropic phase formed by coalescence of mesophase spheres. BULK MESOPHASE retains fluidity and is deformable in the temperature range up to about 770 K and transforms into GREEN COKE by further loss of hydrogen or low‐molecular‐weight species.
See: GREEN COKE.
Notes
This BULK MESOPHASE can sometimes be formed directly from the isotropic PITCH without observation of intermediate spheres.
See: PITCH.
Calcined Coke
Description
CALCINED COKE
