Studying of 2D Titanium Carbide Structure by Raman Spectroscopy after Heat Treatment in Argon and Hydrogen Atmospheres

Here in we show the effect of heat treatment of two dimensional layered titanium carbide structure (Ti3C2Tx), so called MXene. As prepared MXene has functional groups -OH, -F, -Cl. In order to remove the functional groups we heat treated the MXene in Ar (with 0.01% O2) and H2 (with 0.01% H2O) atmospheres. We discovered the significant decrease in the amount of functional groups (-F and -Cl) and increase in the -O content, which refers to the oxidation of the material. Also we determined the optimal regime for Raman spectroscopy in order to avoid any changes in the structure of the material. We revealed that titanium carbide changes its structure at 700 °C and 900 °C into two different titanium dioxide modifications like rutile and anatase in Ar (with 0.01% O2) atmosphere. Also there are small changes occurred in Ti3C2Tx structure and formation of amorphous carbon after 700 °C treatment in H2 (with 0.01% H2O) atmosphere and formation of TiO2 (rutile) at 900 °C. Energydispersive X-ray spectroscopy (EDX) revealed the reduction of functional groups at 700 °C in both atmospheres and total disappearance of –F and –Cl and increasing the oxygen at 900 °C. The huge increase of oxygen by atomic percent, can be explained by the initial oxygen content in argon and hydrogen gases

СТРУКТУРНЫЕ ОСОБЕННОСТИ КОСТНОЙ ТКАНИ ПРИ КОКСАРТРОЗЕ, ВЫЯВЛЕННЫЕ МЕТОДОМ СПЕКТРОСКОПИИ КОМБИНАЦИОННОГО РАССЕЯНИЯ СВЕТА

The structure of human bone slices taken from patients suffering from deforming arthrosis of the hip joint (coxarthrosis) was studied by Raman spectroscopy. Comparative analysis of healthy and sick bone tissues was made on the basis of the intensity ratio of RS bands associated with organic and mineral components. It was shown that coxarthrosis results in a relative increase of an organic component and in a higher degree of substitution of phosphate groups by carbonate ones in the hydroxyapatite lattice. Методом спектроскопии комбинационного рассеяния света исследована структура срезов костной ткани людей, страдающих деформирующим артрозом тазобедренного сустава (коксартроз). Проведен сравнительный анализ срезов здоровых и больных участков костной ткани по соотношению интенсивностей полос комбинационного рассеяния, характеризующих долю органической и минеральной фазы. Показано, что для разрушенной в результате коксартроза костной ткани характерна более высокая доля органической составляющей и более высокая степень замещения фосфатной группы на карбонатную в решетке гидроксиапатита.

CVD graphene growth on a surface of liquid gallium

Abstract This paper presents the results of the experiments on graphene growth on the surface of a liquid metal gallium that appeared to have the catalytic ability in respect to carbon atoms. Due to the absence of crystal lattice, the liquid catalyst does not influence the graphene formation and as a result, the latter has uniform hexagonal structure. The work comprises the data on graphene synthesis on the surface of pure gallium with different precursors and on the surface of pre-treated gallium without any precursor. Obtained materials were characterized by RAMAN, TEM, SEM and FT-IR techniques

The effect of cross rolling on the microstructure of ferrous and non-ferrous metals and alloys

The cross rolling is the one of most perspective method of refinement microstructure metals by severe plastic deformation method. This method gives ability to get the long length billets. However, deformation and trajectories of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element method (FEM) simulation of hot cross rolling and experimental study of the effect of the cross rolling on a different threeroll mills on the microstructure of ordinary structural alloy steel, stainless steel and technical copper in different zones of the bar. Analysis showed significant structure refinement in all cases. The best result was achieved on the stainless steel, and shown the formation of equal-axis ultra-fine-grain structure on the bar periphery