Observation of Carbonic Acid Formation from Interaction between Carbon Dioxide and Ice by Using in situ Modulation Excitation IR Spectroscopy

Author(s):  
Thomas Bürgi ◽  
Xianwei Wang
2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.


2018 ◽  
Vol 22 (2) ◽  
pp. 297-300
Author(s):  
V.V. Nevmerzhitsky ◽  
V.Yu. Ivannik ◽  
V.V. Kazmirchuk ◽  
T.N. Moiseenko ◽  
T.A. Volkov ◽  
...  

The fight against staphylococcal infection, increasing the effectiveness of methods of prevention and treatment of diseases of staphylococcal etiology is of interest to scientists and practitioners, both in Ukraine and around the world. The urgency of this problem is growing rapidly, as there is a tendency to increase the resistance of not only staphylococci, but also other gram-positive bacteria. The spread of methicillin-resistant staphylococci restricts the choice of antibiotics for the treatment of diseases of staphylococcal etiology. Staphylococcus aureus is the most common and dangerous type, which is one of the main factors of purulent-inflammatory lesions of the skin and mucous membranes. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. One of the unique and promising medicinal plants, which contains a rich complex of biologically active substances (BAS), is common hops (Humulus lupulus L.). The complex of BAS (flavonoids, hormones, vitamins, bitter, phenolic compounds, essential oils) causes anti-inflammatory, bactericidal, hyposensitizing and analgesic action of hops. The purpose of this work is to determine the antistaphylococcal activity of the carbon dioxide extract of hops and to justify the development on its basis of new antimicrobial agents for the prevention and treatment of infectious and purulent-inflammatory diseases. The following methods were used: microbiological (method of diffusion into agar (well method)) and mathematical and statistical. The high antimicrobial activity of the carbon dioxide extract of hops has been established for museum test strains of the genus Staphylococcus. The results of the studies testify to the prospects of further study of the bactericidal properties of the extract of hops carbon dioxide with the aim of creating effective antimicrobial agents on its basis for the prevention and treatment of infectious and purulent-inflammatory diseases of staphylococcal etiology.


1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.


1980 ◽  
Vol 45 (8) ◽  
pp. 2219-2223 ◽  
Author(s):  
Marie Jakoubková ◽  
Martin Čapka

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.


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