scholarly journals Production of Bitumen Modified with Low-Molecular Organic Compounds from Petroleum Residues. 1. Effect of Solvent Nature on the Properties of Petroleum Residues Modified with Folmaldehyde

2021 ◽  
Vol 15 (2) ◽  
pp. 274-283
Author(s):  
Michael Bratychak ◽  
◽  
Volodymyr Gunka ◽  
Yuriy Prysiazhnyi ◽  
Yurii Hrynchuk ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Ir Spectroscopy ◽  
Organic Solvent ◽  
Organic Compounds ◽  
Initial Material ◽  
Effect Of Solvent ◽  
Petroleum Residues ◽  
Solvent Molecules ◽  
Bitumen Modification

The possibility of petroleum residues (tar and oxidized bitumen) modification with formaldehyde (37 % aqueous solution) has been studied at the temperature of 393±3 K for 3 h in the presence of organic solvent and using hydrochloric acid as a catalyst. Toluene, p-xylene, naphta solvent and n-octane were used as the solvents in the amount of 0–40 wt % relative to the initial material. By means of IR spectroscopy the resin-like compounds affecting the operational properties of petroleum residues have been detected. These compounds are formed as a result of formaldehyde reaction with residue components and solvent molecules.

Influence of Solvent Composition (Water—Dioxane Mixtures) on the Formation Degree of Intramolecular Aromatic-Ring Stacks in Binary Cu(L-Phenylalaninate)2, Cu(L-Tryptophanate)2, and Related Complexes

1989 ◽  
Vol 44 (12) ◽  
pp. 1555-1566 ◽  
Author(s):  
Guogang Liang ◽  
Helmut Sigel
Keyword(s):  
Aqueous Solution ◽  
Organic Solvent ◽  
Aromatic Ring ◽  
Side Chain ◽  
Amino Acid Side Chain ◽  
High Concentrations ◽  
General Experience ◽  
Solvent Molecules ◽  
The Stability ◽  
Hydrophobic Solvation

The stability constants of the binary Cu(AA)+ and Cu(AA)2 complexes, where AA⁻ = L-phenyl-alaninate (Phe⁻) or L-tryptophanate (Trp⁻), have been determined by potentiometric pH titrations in water, and in 30, 50, 70 and 80% (v/v) dioxane—water mixtures (I = 0.1 M, NaNO3; 25 °C); the corresponding data for the complexes with L-alaninate (Ala⁻), L-valinate (Val⁻), L-norvalinate (Nva⁻), and L-leucinate (Leu⁻) are taken from our recent work (G. Liang, R. Tribolet, and H. Sigel, inorg. Chim. Acta 155, 273 (1989)). The overall stability of Cu(AA)+ and Cu(AA), is governed for all amino acetates (AA⁻) by the polarity of the solvent, while the extent of the intramolecular stack formation between the aromatic side chains in Cu(AA)2 is influenced by the hydrophobic solvation properties of the organic solvent molecules (i.e., the ethylene units of dioxane). Based on the stability difference Δ log K*AA = log KCu(AA)Cu(AA)2-log KCu(AA)Cuit is shown that Cu(Phe)2 and Cu(Trp)2 are more stable than Cu(Ala)2, and this increased stability is used for evaluating the extent of the stack formation (= closed form) in Cu(Phe)2 and Cu(Trp)2: the percentages of the closed forms vary between about 25 and 80% (based on Cu(AA),2/tot,), and those for Cu(Val)2, Cu(Leu)2 and Cu(Nva)2 between about 10 and 30%. The formation degree of the intramolecular side-chain adduct in Cu(AA)2 decreases (in most solvents), as one might expect, within the series: Cu(Trp)2 > Cu(Phe)2 > Cu(Val)2≳ Cu(Leu)2≳ Cu(Nva)2. The corresponding observations are made with M(AA)2 complexes of Co2+, Ni2+, and Zn2+. The influence of the organic solvent on the intramolecular hydrophobic and stacking adducts differs somewhat: (i) Stack formation in Cu(Phe)2 and Cu(Trp)2 is slightly inhibited by the presence of dioxane, but even in 50% (v/v) dioxane—water the formation degree of the aromatic-ring stacks is still more than 50%. (ii) Addition of some dioxane to an aqueous solution containing Cu(Val)2, Cu(Leu)2or Cu(Nva)2 favors the formation of the aliphatic side-chain adducts; the largest formation degree being reached close to a content of 70% dioxane. Both observations contrast with the general experience made at unbridged hydrophobic or stacking adducts: these are considerably destabilized already by the addition of relatively small amounts of an organic solvent to an aqueous solution. Such a destabilization of the closed Cu(AA)2 species occurs only at high concentrations of the organic solvent (usually more than 70%). It should be added that the organic solvent most probably influences the structure of the intramolecular ligand-ligand adducts giving rise to a whole series of “closed” species; a resolution is presently not possible and therefore the whole stability increase is attributed to a (single) so-called “closed” species to allow a quantification of the effect. The relevance of amino acid side-chain interactions regarding cooperativity, selectivity, evolutionary aspects, and low polarity regions, as in active-site cavities of proteins, are shortly indicated.

Bis(triphenylphosphoranylidene)ammonium Dicyanoaurate(I)

2002 ◽  
Vol 57 (10) ◽  
pp. 1085-1089 ◽  
Author(s):  
Ruei-Yang Liau ◽  
Hendrik Ehlich ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Ir Spectroscopy ◽  
Structure Data ◽  
Crystal Structure Data ◽  
Literature Survey ◽  
Solvent Molecules ◽  
Short Contacts

AbstractPartially 13C-labeled alkali dicyanoaurates M[Au(CN)2] were prepared and investigated by NMR and IR spectroscopy in aqueous solution. For the range of concentration investigated the data obtained under standard conditions provided no evidence for anion association. The salt [Ph3PNPPh3][Au(CN)2] was also prepared and the crystal structure of the dichloromethane solvate determined. There is no anion aggregation in the crystal, and short contacts of the anions are only discernible with the solvent molecules. A literature survey of crystal structure data for dicyanoaurate(I) salts (almost 35 entries) show that inter-anionic contacts are only observed in structures with small cations or with cations exerting a directional influence.

scholarly journals Production of Bitumen Modified with Low-Molecular Organic Compounds from Petroleum Residues. 3. Tar Modified with Formaldehyde

2021 ◽  
Vol 15 (4) ◽  
pp. 608-620
Author(s):  
Volodymyr Gunka ◽  
◽  
Yuriy Prysiazhnyi ◽  
Yurii Hrynchuk ◽  
Iurii Sidun ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Ir Spectroscopy ◽  
Chemical Modification ◽  
Organic Compounds ◽  
Group Composition ◽  
Process Time ◽  
Structural Group ◽  
Brittle Point ◽  
Structural Group Composition

The chemical modification of tar with formaldehyde as 37% aqueous solutionhas been studied in the presence of the catalysts. Hydrochloric acid, sulfuric acid, sodium hydroxide and acid tar were used as the catalysts. The effect of the catalyst nature and amount, as well as temperature, process time and initial components ratio on the softening point, penetration, brittle point and adhesion to crushed stone has been determined. The structure of the modified tars was confirmed by IR spectroscopy. The structural-group composition was determined. Arene-formaldehyde resins have been synthesized on the basis of toluene and modified tars using hydrochloric acid as a catalyst. The synthesized resins were characterized using IR spectroscopy. The chemistry of the tar modification with formaldehyde has been proposed.

Mono/bimetallic water-stable lanthanide coordination polymers as luminescent probes for detecting cations, anions and organic solvent molecules

2016 ◽  
Vol 45 (32) ◽  
pp. 12710-12716 ◽  
Author(s):  
Huarui Wang ◽  
Jianhua Qin ◽  
Chao Huang ◽  
Yanbing Han ◽  
Wenjuan Xu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Organic Solvent ◽  
Coordination Polymers ◽  
Luminescent Probes ◽  
Lanthanide Coordination Polymers ◽  
Emission Quenching ◽  
Solvent Molecules

Eleven water-stable isostructural mono/bimetallic {[EuxTb1−x(HL)(H2O)3]·H2O}n were prepared. The Ln-CPs showed the emission quenching induced by Fe3+, Cr3+ cations and CrO42−, CO32− anions in aqueous solution.

Studying dispersed and rheological properties of hydrocarbon-containing acid emulsions and their efficiency in removing asphalt-resin-paraffin deposits

2020 ◽  
pp. 128-139
Author(s):  
M. Yu. Shumakher ◽  
V. V. Konovalov ◽  
A. P. Melnikov
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Rheological Properties ◽  
Reaction Rate ◽  
Experimental Studies ◽  
Efficient Removal ◽  
Reservoir Properties ◽  
Hydrocarbon Solvents ◽  
Formation Zone ◽  
Effect Of The Composition

Currently, the treatment of the bottomhole formation zone with acidic compositions is one of the most common methods to intensify the oil inflow. The use of various modified acid compositions increases the efficiency of acid treatments on the bottomhole formation zone. Acid compositions, including those containing hydrocarbon solvents, which contribute to more efficient removal of organic colmatants, affect the reaction rate of the reagent with the rock and processing equipment, change the reservoir properties, etc.The article presents the results of experimental studies, which are aimed at establishing the effect of the composition of hydrocarbon-containing acidic emulsions consisting of an aqueous solution of hydrochloric acid, toluene and Neonol AF 9-10 on their dispersed and rheological properties, as well as their efficiency in removing paraffin deposits.

scholarly journals Efficient Lipid Bilayer Formation by Dipping Lipid-Loaded Microperforated Sheet in Aqueous Solution

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 53
Author(s):  
Nobuo Misawa ◽  
Satoshi Fujii ◽  
Koki Kamiya ◽  
Toshihisa Osaki ◽  
Shoji Takeuchi
Keyword(s):  
Aqueous Solution ◽  
Membrane Protein ◽  
Organic Solvent ◽  
Lipid Membrane ◽  
Coating Layer ◽  
Bilayer Lipid Membrane ◽  
Contact Method ◽  
Electrical Measurements ◽  
Droplet Interface Bilayer ◽  
Perforated Sheet

This paper describes a method for a bilayer lipid membrane (BLM) formation using a perforated sheet along with an open chamber. Microscopic observation of the formed membrane showed a typical droplet interface bilayer. We proved that the formed membrane was a BLM based on electrical measurements of the membrane protein α-hemolysin, which produces nanopores in BLMs. Unlike the conventional approach for BLM formation based on the droplet contact method, this method provides aqueous surfaces with no organic solvent coating layer. Hence, this method is suitable for producing BLMs that facilitate the direct addition of chemicals into the aqueous phase.

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

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