Methods of Direct Reaction Theories

The continuous ozonation of polycyclic aromatic hydrocarbons (PAH) was studied in a two stage ozonation system followed by serobic biological degradation. The highly condensed PAH benzo(e)pyrene and benzo(k)fluoranthene were oxidized selectiely in synthetic oil/water-emulsions. The influence of the ozone mass transfer gas-liquid on the reaction rate of benzo(k)fluoranthene was studied for process optimization. The dissolved ozone concentration is influenced by temperature to a higher degree than the reaction rate of PAH. In dependence on pH, PAH oxidation occurs by a direct reaction with ozone inside the oil droplets. Two main ozonation products of benzo(e)pyrene were quantified at different retention times during ozonation and their transformation could be shown in the biological treatment step.

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Synthesis and Compressibility of Novel Nickel Carbide at Pressures of Earth’s Outer Core

Minerals ◽

10.3390/min11050516 ◽

2021 ◽

Vol 11 (5) ◽

pp. 516

Author(s):

Timofey Fedotenko ◽

Saiana Khandarkhaeva ◽

Leonid Dubrovinsky ◽

Konstantin Glazyrin ◽

Pavel Sedmak ◽

...

Keyword(s):

Equation Of State ◽

Outer Core ◽

Direct Reaction ◽

Volume Data ◽

X Ray Diffraction ◽

Nickel Carbide ◽

Diamond Anvils ◽

Group A ◽

Diamond Anvil ◽

Murnaghan Equation

We report the high-pressure synthesis and the equation of state (EOS) of a novel nickel carbide (Ni3C). It was synthesized in a diamond anvil cell at 184(5) GPa through a direct reaction of a nickel powder with carbon from the diamond anvils upon heating at 3500 (200) K. Ni3C has the cementite-type structure (Pnma space group, a = 4.519(2) Å, b = 5.801(2) Å, c = 4.009(3) Å), which was solved and refined based on in-situ synchrotron single-crystal X-ray diffraction. The pressure-volume data of Ni3C was obtained on decompression at room temperature and fitted to the 3rd order Burch-Murnaghan equation of state with the following parameters: V0 = 147.7(8) Å3, K0 = 157(10) GPa, and K0' = 7.8(6). Our results contribute to the understanding of the phase composition and properties of Earth’s outer core.

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Solvent-free synthesis of symmetric methylene diesters via direct reaction of aromatic carboxylates with 1,n-dihaloalkanes

RSC Advances ◽

10.1039/d1ra04814g ◽

2021 ◽

Vol 11 (46) ◽

pp. 28711-28715

Author(s):

Lin Bai ◽

Shenglong Ding ◽

Xiaofang Ma

Keyword(s):

Solvent Free ◽

Direct Reaction ◽

Highly Efficient ◽

Solvent Free Conditions ◽

Aromatic Carboxylates ◽

Solvent Free Synthesis

This work provides a highly efficient and feasible strategy for the synthesis of symmetric methylene diesters, involving the direct diesterification of various carboxylates with 1,n-dihaloalkanes under solvent-free conditions.

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