Crystalline carbon

Mezcaline (Mescaline), CnHijOjN, is a colourless alkaline oil, b.p. 180-180-5°/12 mm., which absorbs carbon dioxide from the air, forming a crystalline carbonate. The sulphate, Bj.HjSO4.2HjO, m.p. 183-6°, forms brilliant prisms the hydrochloride, m.p. 181°, coloirrless crystals picrate, m.p. 216-8° and the platinichloride (B. HCl)j. PtCl4, m.p. 

Diamond is a naturally occurring form of pure, crystalline carbon. Each carbon atom is surrounded by four others arranged tetrahe-drally. The result is a compact structural network bound by normal chemical bonds. This description offers a ready explanation for the extreme hardness and the great stability of carbon in this form. 

Diamonds consist of pure, crystalline carbon (virtually single crystals). These artistically cut and brilliant stones pack a lot of value in the tiniest of volumes. 

Raman microscopy provides a spatial resolution slightly better than IR, and no sample preparation is necessary in many cases. It has advantages with special types of substances (e.g., systems containing conjugated double bonds, oriented systems, amorphous and crystalline carbon, oxides). SNOM techniques (with spatial resolution below 1 pm) have been more popular with Raman than with IR, so far, but as yet are not routinely practiced. 

Murphy, W.L. and Mooney, D.J. (2002) Bioinspired growth of crystalline carbonate apatite on biodegradable polymer substrata. Journal of the American Chemical Society, 124, 1910-1917. 

The commonest crystalline forms of carbon, cubic diamond and hexagonal graphite, are classical examples of allotropy that arc found in every chemistry textbook. Both diamond and graphite also exist in two minor crystallographic forms hexagonal diamond and rhombohedral graphite. To these must be added carbynes and Fullerenes, both of which are crystalline carbon forms. FulleTenes are sometimes referred to as the third allotrope of carbon. However, since Fullerenes were discovered more recently than carbynes, they are... 

Xu, G. Aksay, I. A. Groves, J. T. Continuous Crystalline Carbonate Apatite Thin Films. 

The many forms of so-called amorphous (non-crystalline) carbon such as charcoals and lampblack are all actually microcrystalline forms of graphite. The latter has a covalently bonded layer structure comprising a network of joined flat hexagonal Ce rings where the separation of the layers is reported to be 3.35A. This is about equal to the sum of the Van der Waals (intermolecular) radii, indicating that the forces between layers should be relatively slight, as is evidenced by the observed softness and lubricity of the material. 

While diamond is the hardest naturally occurring material, the most common form of crystalline carbon is the much softer and flexible graphite. Graphite occurs as sheets of... 

As with transmission analysis, DRIFTS test samples are generally ground and mixed with an IR transparent salt, such as potassium bromide (KBr), prior to sampling. However, to ensure that there is no catalytic effect, most systems use CaF2 or powdered crystalline carbon (diamond). One drawback is the presence of reststrahlen bands whose contrast can be reduced by... 

Piacentini et al., 2005). It was resulted that there were three different Ba-containing species amorphous BaO on A1203 surface, amorphous carbonates and crystalline carbonate. Amorphous carbonate showed relatively low thermal stability and possesses high reactivity for NOx storage. 

H. St. C. Deville also succeeded in preparing only the two crystalline carbonates— viz. the sesquicarbonate and the acid carbonate. 

The most common of these pigments are certain earths, such as Sienna or Italian earth—which is a brown ochre—umber, Cologne earth or Cassel brown blacks with a carbon basis graphite, consisting of more or less impure crystalline carbon. 

Small carbon grains are assumed to be the carrier of the prominent interstellar ultra violet absorption at 217 nm. To investigate this hypothesis, we produced small carbon particles by evaporating graphite in an inert quenching gas atmosphere, collected the grains on substrates, and measured their optical spectra. In the course of this work - which in the decisive final phase was carried out with the help of K. Fostiropoulos and L. D. Lamb - we showed that the smoke samples contained substantial quantities of C60. The fullerene C60 (with small admixtures of C70) was successfully separated from the sooty particles and, for the first time, characterized as a solid. We suggested the name fullerite for this new form of crystalline carbon. 

Mudstone Wackestone Packstone Gramstone Boundstone Crystalline carbonate... 

Discovery of crystalline solid C60 was actually the finding of a new form of crystalline carbon, being different in dimensionality from graphite, two-dimensional sp2 carbon. It is also different from diamond, three-dimensional sp3 carbon. From this viewpoint, crystalline C60 polymers produced via high-pressure and... 

Kanno et al. studied less crystalline carbons like pyrolyzed polymers and commercial carbon fibers. They reported an irreversible charge capacity in the first cycle related to the carbon surface. However, the reversible charge capacity which they could observe over several cycles was independent of the surface reaction.106 Mohri et al.107 demonstrated only 20% capacity fading over 500 cycles with a lithium-ion cell containing a lithium metal oxide and low crystallinity pyrolytic carbon electrode. 

At the first glance, the use of conductive additives does not seem to be necessary for negative carbon electrodes due to their significant intrinsic electronic conductivity (especially of the crystalline carbon active materials). However, in most of the commercial carbon negative electrodes,... 

Another school of thought believes that the efficacy of boric oxide in afterglow suppression is related to its high ionization energy/or electron affinity active sites for oxygen adsorption on the char surface may be deactivated by boric oxide via electron transfer. It was reported that boric oxide increases the oxidation temperature of crystalline carbon from 700°C to 800°C.109... 

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