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The effect of the shock wave loading on films of amorphous carbyne was investigated. Chemically synthesized films were deposited on 1 mm thick copper disks. X-ray and transmission electron microscopy studies of 10 and 150 micron carbyne films recovered after shock loading at pressures of 18, 26 and 36 GPa. Ten micron films partially transformed to carbyne crystals with a size of 1 micron. Thick films of carbyne transformed to a mixture of amorphous carbon phase and nanocrystalline cubic diamond.

Abstract: Shock compressibility of C60 fullerite and sound velocities in shock-compressed fullerite were experimentally studied at the pressures range up to ∼50 GPa. In our experiments, we used polycrystalline C60 specimens with a density of 1.64 g/cc. The Hugoniot of C60 fullerite had a set of peculiarities, which may be attributed to a series of polymorphic phase transitions. The jump of sound velocity in shocked C60 at pressure ∼9 GPa indicates the formation of a rather hard carbon phase. It is possible to assume that it is a polymerized C60 phase. In the region of pressures 9–25 GPa, destruction of this phase and formation of a graphite-like carbon occurs. With further growth of shock pressure, phase transition of the graphite-like carbon to a diamond-like phase is observed with a transition onset pressure ∼25 GPa. If shock pressures are higher than ∼33 GPa, Hugoniot of C60 fullerite is determined by the thermodynamic properties of the diamond-like phase. [Copyright &y& Elsevier]

Simple, safe, scalable and low-cost method of hydrogen production via aluminum-water reaction was proposed. Hydrogen generation method is based on oxidation of coarse aluminum of centimetric scale in alkali aqueous solution with alkali concentration of no more than 0.1 M under intensive mixing of reaction medium. In presented work aluminum conversion (hydrogen yield) was studied depending on the aluminum to solution mass ratio (α changed from 30.1 to 2.7), the concentration of alkali in aqueous solution, the mixing rate, the form of aluminum particles (granules or chips) and chemical purity of aluminum. It was shown that under implemented experimental conditions alkali is continuously regenerated during oxidation reaction and synergistic effect of low content alkali aqueous solution and intensive mixing works. Aluminum conversion degree after 5 h oxidation of aluminum chips at 90 °C in 0.1 M KOH aqueous solution with α = 4 and mixing rate of 400 rpm was 75.4%. With alkali concentration increasing from 0.01 M to 0.3 M the conversion of aluminum increases from 20.7 to 95.7% (after 5 h at 90 °C, α = 4). Proposed method was strongly affected by mixing of reaction medium inside the reactor while it didn't feel the difference between aluminum chips and granules having specific surface area of 22 and 5.5 cm 2 /g respectively. Chemical purity of aluminum had little effect on aluminum conversion as well. Generally, proposed method can be used for hydrogen generation, aluminum waste utilization and special-grade alumina production. [ABSTRACT FROM AUTHOR]

Hydrogen forming by aluminium oxidation with liquid water of water solutions at low temperatures is complicated by the following reasons. Firstly, on an aluminium surface a film of oxide is formed effectively preventing further oxidation. Secondly, the rate of aluminium oxidation considerably decreases as the temperature of the system decreases. However, in this study the methods are given which enable one to overcome the above difficulties. The experiments on the oxidation of powdered activated aluminium in different water solutions have been carried out. The data obtained have been used to plot a number of curves characterizing hydrogen flow rates depending on the solution composition and the temperature of the process (the original weight of the powder was 0.25 g, solution volume - 300 ml, measuring time - 180 min). At −40 °C for KOH solution the yield of hydrogen was 50 ml, for CaCl 2 – about 5 ml, and for ZnCl 2 – approximately 2 ml. At −10 °C H 2 yield for NaOH was 264 ml, for KOH – 260 ml; at −20 °C: 100 ml for NaOH, and 225 ml for KOH. For KOH solution at temperatures of −30 °C and −40 °C the yields were equal to 192 and 49 ml respectively. Oxidation of granulated non-activated aluminium (2.5 g of aluminium per 300 ml of solution) with hydrochloric acid solution in the presence of CuCl 2 (2.5 g per 300 ml of solution) resulted in generation of more than 2000 ml of hydrogen during 300 min. For FeCl 3 solution the total value of hydrogen obtained during 180 min was equal to 70 ml, it also has been observed partial freezing of this solution. [ABSTRACT FROM AUTHOR]

Abstract: A new semiempirical equation of state for the simple cubic phase of C60 fullerite is proposed. A critical analysis of calculated results in comparison with available high-temperature, high-pressure experimental data is made. Physical–chemical transformations observed in recent experiments on shock compression of C60 fullerite are discussed in view of equation-of-state calculations for the simple cubic phase of C60 fullerite as well as for the graphite and diamond phases of carbon. [Copyright &y& Elsevier]