Selective electrooxidation of acetaldehyde in aqueous ethanol alkaline solutions on silver-containing electrodes

2021 ◽  
pp. 138076
Author(s):  
S.A. Kleinikova ◽  
K.V. Gor'kov ◽  
E.V. Gerasimova ◽  
N.N. Dremova ◽  
E.V. Zolotukhina
Keyword(s):  
Aqueous Ethanol ◽  
Alkaline Solutions

Chelating equilibria of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and 4-(2-pyridylazo)resorcinol with La(III) ions

1988 ◽  
Vol 53 (3) ◽  
pp. 526-542
Author(s):  
Dimitrii Borisovich Gladilovich ◽  
Vlastimil Kubáň ◽  
Josef Havel
Keyword(s):  
Absorption Band ◽  
Organic Solvent ◽  
Aqueous Solutions ◽  
Equilibrium Constant ◽  
Absorption Maximum ◽  
Aqueous Ethanol ◽  
Equilibrium Constants ◽  
Organic Component ◽  
Alkaline Solutions ◽  
Hydrolysis Products

2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (BrPADAP) with lanthanum(III) ions in 50% (v/v) aqueous ethanol or 30-50% (v/v) aqueous dimethylformamide (DMF) forms unprotonated chelates ML and ML2 characterized by a double absorption band with maxima at 550 and 570 nm. The ML2 species is rather unstable, hydrolyzing readily to the M(OH)L chelate, which exhibits an absorption maximum at 570 nm. The molar absorptivities of the ML, ML2, and M(OH)L species, lying in the regions of 5.3-6.5, 7.0-7.2, and 6.5-7.2 m2 mmol-1, respectively, depend on the kind and fraction of the organic component in the solvent. The conditional equilibrium constants (-log βpqr = 3.3-4.0, 12.2-12.5, and 7.8-8.2, respectively) decrease with increasing fraction of the organic solvent; in systems with high proportions of ethanol orDMF, the formation of higher species is greatly suppressed. 4-(2-Pyridylazo)resorcinol (PAR) with La(III) in acid aqueous solutions forms the MLH and ML species with absorption maxima at 490 and 506 nm, respectively ( ε = 1.2 and 2.5 m2 mmol-1, respectively) and with conditional equilibrium constants –log βpqr = -3.4 and 3.5, respectively. In alkaline solutions with excess PAR, the ML2 species with the absorption maximum at 509 mn (ε = 4.6 m2 mmol-1) and conditional equilibrium constant –log βpqr = 8.1 is formed. This chelate hydrolyses readily forming the M(OH)L species and other hydrolysis products. The ML2 species of the two reagents, forming in ammoniacal buffer at pH 9.0 – 9.5 (PAR) and 8.2 – 8.4 (BrPADAP), can be used for a sensitive (ε = 3.8 and 6.1 m2 mmol-1, respectively) post-column derivatization of lanthanoids after their separation by IEC or HPLC or for their FIA determination.

Sol-gel transition in silica alkaline solutions. A NMR study

1994 ◽  
Vol 91 ◽  
pp. 901-908 ◽  
Author(s):  
H Zanni ◽  
P Nieto ◽  
L Fernandez ◽  
R Couty ◽  
P Barret ◽  
...  
Keyword(s):  
Sol Gel ◽  
Alkaline Solutions ◽  
Nmr Study ◽  
Sol Gel Transition ◽  
Gel Transition

Evaluation of a molybdenum sulfide reference electrode in hot alkaline solutions

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 35-41
Author(s):  
OUTI A. HYÖKYVIRTA ◽  
TOM E. GUSTAFSSON
Keyword(s):  
Molybdenum Disulfide ◽  
Surface Film ◽  
Reference Electrode ◽  
Exposure Period ◽  
Molybdenum Sulfide ◽  
Alkaline Solutions ◽  
Internal Reference ◽  
Cell Potential ◽  
Pulp Digester ◽  
Alkaline Sulfide

This investigation evaluated the applicability of a molybdenum sulfide reference electrode (MSRE) as an internal reference electrode for use in alkaline sulfide solutions over a range of pulp digester liquors at 170°C. The electrode remained stable during the exposure period of two weeks. The experimentally determined half cell potential of the MSRE is E = -0.91 VSHE. The surface of the MSRE was examined by scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA) to verify the chemical composition of the thin surface film. Based on ESCA studies, the surface film contained molybdenum disulfide and sodium disulfide. During storage of the specimens, sulfide was partly oxidized to sodium sulfite in air. Next to the metallic molybdenum, a mixed molybdenum disulfide and molybdenum hydroxide layer was detected.

Effects of Interfacial Reaction on the Radial Displacement of Oil by Alkaline Solutions

1990 ◽  
Vol 45 (2) ◽  
pp. 231-244 ◽  
Author(s):  
H. A. Nasr-El-Din ◽  
K. C. Khulbe ◽  
V. Hornof ◽  
G. H. Neale
Keyword(s):  
Interfacial Reaction ◽  
Radial Displacement ◽  
Alkaline Solutions

ACI TYPE CB-30

Alloy Digest ◽  
1975 ◽  
Vol 24 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Nitric Acid ◽  
Chromium Content ◽  
Heat Treating ◽  
Alkaline Solutions ◽  
Chromium Alloy ◽  
Iron Chromium Alloy ◽  
Iron Chromium

Abstract Type CB-30 is an iron-chromium alloy sufficiently high in chromium content to provide excellent resistance to corrosion by nitric acid, alkaline solutions and many organic chemicals. They alloy maintains an essentially ferritic structure. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-315. Producer or source: Stainless steel foundries.

Precipitation of kraft lignin by metal cations in alkaline solutions

2000 ◽  
Vol 15 (4) ◽  
pp. 306-312 ◽  
Author(s):  
Jonas Sundin ◽  
Nils Hartler
Keyword(s):  
Metal Cations ◽  
Kraft Lignin ◽  
Alkaline Solutions

Chemical deposition of hard composite coatings Ni–Cu–P–Cr2O3

2020 ◽  
pp. 179-181
Author(s):  
A.A. Abrashov A.A. ◽  
E.G. Vinokurov ◽  
M.A. Egupova ◽  
V.D. Skopintsev
Keyword(s):  
Chromium Oxide ◽  
Alkaline Solution ◽  
Composite Coatings ◽  
Chemical Deposition ◽  
Alkaline Solutions ◽  
Functional Surface ◽  
Heat Treated ◽  
Weakly Acid Solution ◽  
Coating Composition ◽  
Weakly Acidic Solution

The technological (deposition rate, coating composition) and functional (surface roughness, microhardness) characteristics of chemical composite coatings Ni—Cu—P—Cr2O3 obtained from weakly acidic and slightly alkaline solutions are compared. It is shown that coatings deposited from slightly alkaline solution contain slightly less phosphorus and chromium oxide than coatings deposited from weakly acid solution (2...3 % wt. phosphorus and up to 3.4 % wt. chromium oxide), formed at higher rate (24...25 microns per 1 hour of deposition at temperature of 80 °C), are characte rized by lower roughness and increased microhardness. The Vickers microhardness at 0.05 N load of composite coatings obtained from slightly alkaline solution and heat-treated at 400 °C for 1 hour is 13.5...15.2 GPa, which is higher than values for coatings deposited made of weakly acidic solution. The maximum microhardness of coatings is achieved at concentration 20 g/l of Cr2O3 particles. The technology of chemical deposition of Ni—Cu—P—Cr2O3 coatings formed in slightly alkaline solution is promising for obtaining of materials with increased hardness and wear resistance.

The Inhibitory Effect of Panax Ginseng Extract on Amyloid-like Fibril Formation of Trypsin in Aqueous Ethanol

2018 ◽  
Vol 25 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Phanindra B. Kasi ◽  
Marta Kotorman ◽  
Attila Borics ◽  
Beata G. Hervay ◽  
Kinga Molnar ◽  
...  
Keyword(s):  
Panax Ginseng ◽  
Aqueous Ethanol ◽  
Inhibitory Effect ◽  
Fibril Formation ◽  
Ginseng Extract
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