Graphite lamellae

Organic materials undergo pyrolytic decomposition when heated in an inert atmosphere. Polyaromatic ring structures are developed in the early stages of carbonization. As the heat-treatment temperature (HT1) is increased the solid char or coke begins to acquire short-range order with the formation of distorted graphitic lamellae. In addition, localized and anisotropic densification leads to the development of free space between the lamellae. 

Molybdenum disulhde (M0S2), graphite, hexagonal boron nitride, and boric acid are examples of lamella materials commonly applied as solid lubricants. The self-lubricating nature of the materials results from the lamella crystalline structure that can shear easily to provide low friction. Some of these materials used to be added to oils and greases in powder forms to enhance their lubricity. Attention has been shifted in recent years to the production and use of nanosize particles of M0S2, WS2, and graphite to be dispersed in liquid lubricants, which yields substantial decreases in friction and wear. 

The asymmetry of peak shape is preserved in anthraxolite heated to 1200°C. showing that turbostratic disorder persists in spite of a general enhancement of ordering. The band is also sharper and narrower. This may be interpreted to mean either that fewer class intervals are represented in the crystallite size distribution or that increased ordering of aromatic lamellae has reached the point where graphite (hid) planes are more common. Diffraction peaks of both (100) and (101) fall with the 2-A. band. 

Kyotani, T., Sonobe, N., and Tomita, A. Formation of highly orientated graphite from polyacrylonitrile by using a two-dimensional space between montmorillonite lamellae. Nature 331, 1988 331-333. 

Table II contains the micropore volume equations for model E. The first equation shows the value of the micropore volume for this structural unit, which, logically, will be equal to the volume of one micropore multiplied by the number of micropores in the structural unit (eq. 7). The mass of this unit is known (eq. 6) and, consequently, the specific micropore volume can be calculated. It can be observed that the specific micropore volume only depends on the pore width (w) and on the graphitic crystallite parameters (J and p), being independent of the assumed shape of the lamellas, consequently it can be accept a more real shape (discotic).

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