Agranular carbon

Agranular carbon is a mono-granular or monolithic carbon material with homogeneous microstructure which does not exhibit any structural components distinguishable by optical microscopy. 

The above definition of a homogeneous microstructure does not pertain to pores and structural components which may be visible by contrast differences in optical microscopy with polarized light. As a consequence, glass-like 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. 

Industrial carbon materials (such as electrodes) are mostly polygranular, but special grades are agranular materials, such as glass-like carbon, carbon fibers or pyrolytic carbon. Such materials are covered by the term agranular carbon. 

See agranular carbon, carbon fibers, carbon material, glass-like carbon, pyrolytic carbon... 

See agranular carbon, graphite material, non-graphitic carbon, polycrystalline graphite... 

GLASS-LIKE CARBON is an AGRANULAR, NON-GRAPHITIZABLE CARBON, with isotropy of its structural and physical properties and with a very low permeability for liquids and gases. 

---