X-ray diffraction is a widely used nondestructive method of studying carbon materials. It is employed to study the phase composition of samples, to analyze the qualitative and quantitative composition

The structure of some commercial graphites and carbon materials (CMs) obtained by the low-temperature catalytic graphitization of coal tar pitch with iron salt, needle coke, foamed graphite as the catalysts has been studied. The study was performed using the X-ray diffraction technique with reflections from base plane and their decomposition into two components corresponding to the structural phases of graphite which have different XRD characteristics. Various CMs were compared with respect to the structural phase ratio, distance between polyarene layers in these phases, and sizes of the coherent scattering regions. The (004) reflection provided a better fit of some properties of graphites to the calculated XRD characteristics as compared to calculation from the (002) reflection. In the case of carbonization of coal tar pitch with investigated catalyst additions, prepared carbon materials have a higher degree of graphitization and a crystallite size greater than in the other case of carbonization of the individual pitch. The highest catalytic activity is shown by foamed graphite. It was found that the use of foamed graphite as the catalyst at 800-900 ºC produced carbon materials possessing a crystalline structure with interplanar spacing close to that in commercial graphites, while in the absence of catalyst the coal tar pitch material has an amorphous structure.

Calcium phosphate bions (CPB) are biomimetic mineralo-organic nanoparticles which represent a physiological mechanism regulating the function, transport and disposal of calcium and phosphorus in the human body. We hypothesised that CPB may be pathogenic entities and even a cause of cardiovascular calcification. Here we revealed that CPB isolated from calcified atherosclerotic plaques and artificially synthesised CPB are morphologically and chemically indistinguishable entities. Their formation is accelerated along with the increase in calcium salts-phosphates/serum concentration ratio. Experiments in vitro and in vivo showed that pathogenic effects of CPB are defined by apoptosis-mediated endothelial toxicity but not by direct tissue calcification or functional changes in anti-calcification proteins. Since the factors underlying the formation of CPB and their pathogenic mechanism closely resemble those responsible for atherosclerosis development, further research in this direction may help us to uncover triggers of this disease.

Graphites of different nature—pyrolytic, synthetic, thermally expanded, and natural graphites—were compared using X-ray diffraction analysis based on the (00l) reflection from the main crystal face. It was found that the (002) and (004) reflections are the superpositions of two components, which correspond to the structural phases of graphite with different interplanar spacing. The ratio between the integrated intensities of separated reflection components accounts for the ratio between these phases; along with interplanar spacing, this ratio characterizes graphites and makes it possible to detect difference between them. The long-range orders of reflection from the reference plane are responsible for more precise data on interplanar spacing; therefore, it is proposed to use the (004) reflection for characterizing graphites. A correspondence between the structure peculiarities of graphites determined by this method and the discharge capacity of lithium ion batteries with anodes made from these graphites was demonstrated.

Industrial needle-coke samples from different producers are investigated by X‑ray diffraction and scanning electron microscopy. Their structural parameters L a and L care determined, and...