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Sébastien Simon Johan Sjöblom Duo Wei 《Journal of Dispersion Science and Technology》2016,37(12):1751-1759
This article describes interfacial properties of acidic asphaltenes and their ability to stabilize emulsions. Asphaltenes extracted from crude oil were esterified with methanol to prevent ionization of carboxylic acid at high pH. Interfacial tension (IFT) between water and asphaltenes in xylene was significantly lower in basic than in acidic and neutral media, while the elasticity of the corresponding films was higher. These results are consistent with much more stable asphaltene-based emulsions in basic medium. For ester-asphaltenes, the IFT only showed a slight decrease under basic conditions and the interfacial elasticity was close to that in acidic solutions and only slightly higher than for neutral medium. While the asphaltene-stabilized emulsions showed a strong increase in stability in basic medium, this increase was much less for ester-asphaltene emulsions. Salt influenced the interfacial properties and generally reduced emulsion stability. 相似文献
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Li-cheng Wang Xu-sheng Wang Ji-chao Zhang Xin-wang Song Xu-long Cao Zhen-quan Li 《Journal of Dispersion Science and Technology》2014,35(5):641-646
In order to study the interfacial activity of the anionic-nonionic surfactant, five nonyl phenol polyoxyethylene ether carboxylates were synthesized and mass spectra were used to characterize their structures. The tensions of the anionic–nonionic surfactant aqueous solutions against crude oil were measured and the effects of the surfactant structure, concentration, and salinity on the interfacial activities were discussed. It was shown that nonyl phenol polyoxyethylene (6) ether carboxylate can produce ultralow interfacial tension when the concentrations are not lower than 0.10%, exhibiting a high interfacial activity and a good anti-dilution resistance. Moreover, it was proved that there exists synergism between NaCl and MgCl2 (or CaCl2), which is crucial to achieve the ultralow interfacial tension. 相似文献
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Erland L. Nordgrd Helne Magnusson Ann-Mari D. Hanneseth Johan Sjblom 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,340(1-3):99-108
Novel model compounds are desired to study properties of a narrow group of tetrameric acids from crude oil mainly responsible for naphthenate deposition. It is important to make a comparison to find to what degree the model compounds can reflect the properties of the indigenous tetraacids and where there are deviations, before using the model compounds in naphthenate research. A comparison between two synthesised model compounds and indigenous tetraacids has been carried out regarding physicochemical properties including thermal solid state properties, critical micelle concentrations, monolayer properties and interfacial reactions. Of the two studied model compounds, one was observed to form the same cross-linked network with Ca2+, a typical feature of the indigenous tetraacids. Interfacial reactions using the pendant drop technique also showed that four different divalent cations could all form this network with the model tetraacid. The film formation was however dependent on the ratio M2+/TA. The main deviations were in the solid state, where the model compounds showed crystalline transitions, contrary to the indigenous tetraacids. We conclude that the two different model compounds mimic the indigenous tetraacids well with respect to several of their properties and are suitable for use in naphthenate research. 相似文献
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Xin‐Wang Song Lin Wang Zhen‐Quan Li Lan Luo Sui Zhao 《Journal of Dispersion Science and Technology》2013,34(5):825-828
Two sodium branched‐alkylbenzensulfonates with additional alkyl substituents were synthesized through a series of reactions. The interfacial tension of these alkylbenzenesulfonates between 1.0% NaCl solution and six n‐alkanes were measured. From the data of measurements the following values were calculated: critical micelle concentration (cmc), the interfacial tension at the cmc (γcmc), interfacial excess concentration at the cmc (Γm), area per molecule at the cmc (Am). There were a minimum γcmc and a maximum Γm appeared for the same n‐alkane with increasing the hydrocarbon chain length of the oil. These indicated that the hydrocarbon chain length of oil have the important effect on adsorption and interfacial tension. 相似文献
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新型含硅唑类化合物的合成及其生物活性的研究 总被引:1,自引:0,他引:1
新型含硅唑类化合物的合成及其生物活性的研究李文明,陈馥衡(北京农业大学应用化学系,北京,100094)关键词有机硅化合物,唑类化合物,硅烷化,杀菌活性唑类化合物具有较强的生物活性,已作为杀菌剂广泛地应用于医药和农药,近年来,有机硅化合物作为生物活性物... 相似文献
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Preliminary studies were conducted on the degradation of guaiacylglycerol-β-aryl ether (β-O-4′), phenylcoumaran (β-5′) and biphenyl (5–5′) type lignin model compounds in the organic solvent systems such as ethanol-water (1:1, v/v) and 2-butanone-water (1:1, v/v), in the presence of a di- or trivalent inorganic salt to act as a Lewis acid in the temperature range 140–170°C and with a reaction time up to 60 minutes. The inorganic salts investigated include aluminum chloride, aluminum sulfate, ferric chloride, ferric sulfate, and stannic chloride. The results indicate that lignin model compounds of both phenolic and non-phenolicβ-O-4′ types are susceptible to degradation in organic solvent systems in the presence of one of these salts. Stannic chloride was found to be the most suitable catalyst for the degradation of β-O-4′ type lignin model compounds in the organic solvent systems. In contrast, lignin model compounds of β-5′ and 5–5′ types did not undergo degradation under the same reaction conditions. A possible reaction mechanism for the degradation of β-O-4′ type lignin model compounds in organic solvent system in the presence of stannic chloride is discussed. 相似文献
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Prof. Yueqiang Zhao Dr. Shengkang Wang Dr. Yanjiao Chang Prof. Dr. Weiwei Liu 《Chemphyschem》2023,24(8):e202200801
The nature and strength of intermolecular and surface forces are the key factors that influence the solvation, adhesion and wetting phenomena. The universal cohesive energy prediction equation based on conductor-like screening model (COSMO-UCE) was extended from like molecules (pure liquids) to unlike molecules (dissimilar liquids). A new molecular-thermodynamic model of interfacial tension (IFT) for liquid-liquid and solid-liquid systems was developed in this work, which can predict the surface free energy of solid materials and interfacial energy directly through cohesive energy calculations based on COSMO-UCE. The applications of this model in prediction of IFT for water-organic, solid (n-hexatriacontane, polytetrafluoroethylene (PTFE) and octadecyl-amine monolayer)-liquid systems have been verified extensively with successful results; which indicates that this is a straightforward and reliable model of surface and interfacial energies through predicting intermolecular interactions based on merely molecular structure (profiles of surface segment charge density), the dimensionless wetting coefficient RA/C can characterize the wetting behavior (poor adhesive (non-wetting), wetting, spreading) of liquids on the surface of solid materials very well. 相似文献
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A. M. Al-Sabagh M. M. Zakaa M. R. Noor El-Din 《Journal of Dispersion Science and Technology》2013,34(8):1237-1246
Twelve anionic monoisomeric surfactants based on the alkyl benzene sulfonic acid were prepared. In two sets of experiments, the (nmin) values were determined at 28 and 70°C for them. The n-hydrocarbon scans (n-C5 to n-C18) against the interfacial tension were used to determine the (nmin) values. The factors affecting (nmin) such as; molecular weight, branching of side chain, temperature and electrolyte addition were investigated. From the obtained results, it was found that the surfactants which has the highest molecular (8φ C15 ABS) gave (nmin) equal 8, so it can be used in the enhanced oil recovery(EOR) without additives (the suitable (nmin) for EOR between 7-9). Otherwise, the lowest molecular weight surfactant (7φ C13 ABS) gave (nmin) equal 5 without addition of alcohols or electrolyte. This case needs some additives to adjust the (nmin) in the range of 7 to 9. By investigation the factors affecting (nmin), it was found that the side chain of alkyl benzene shifted the (nmin) to the highest values. The increasing of temperature decreased the (nmin) values. Also, it was found that the (nmin) increased to high value by adding the electrolytes and alcohols. The mixture between surfactants with and without side chain shifted the (nmin) to the highest value. Using these parameters, the alkane carbon number (nmin) can be used to select the suitable solvent during the preparation of emulsion to get the minimum interfacial tension at which the maximum emulsion stability should be obtained and also to select the surfactant for EOR. 相似文献
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Muhammad Sagir Isa M. Tan Muhammad Mushtaq Muhammad Nadeem 《Journal of Dispersion Science and Technology》2014,35(11):1512-1519
The synthesis and use in enhanced oil recovery applications of a novel CO2-philic surfactant derived from maleic anhydride and 2-butyl-1-octanol is reported. The synthesis involved the esterification of maleic anhydride to produce diester followed by sulfonation of the esterified product. The esterification reaction parameters were optimized for the maximum yield of 98.4%. By employing a silica sulfuric acid catalyst, the reaction kinetics of esterification were also investigated. The activation energy was found to be 45.58 kJ/mol. The sulfonation reaction of the esterified product was performed by using sodium bisulfite, and a yield of 82% of surfactant was achieved. The synthesized surfactant lowered the interfacial tension between CO2/brine to 3.1 mN/m and effectively reduced the CO2 mobility. This surfactant has a great potential to be used for CO2 mobility control for CO2?EOR applications. 相似文献
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Dr. Leonid Komissarov Lukas Krep Felix Schmalz Dr. Wassja A. Kopp Prof. Dr. Kai Leonhard Prof. Dr. Toon Verstraelen 《Chemphyschem》2023,24(8):e202200786
This work presents a novel parametrization for the ReaxFF formalism as a means to investigate reaction processes of chlorinated organic compounds. Force field parameters cover the chemical elements C, H, O, Cl and were obtained using a novel optimization approach involving relaxed potential energy surface scans as training targets. The resulting ReaxFF parametrization shows good transferability, as demonstrated on two independent ab initio validation sets. While this first part of our two-paper series focuses on force field parametrization, we apply our parameters to the simulation of chlorinated dibenzofuran formation and decomposition processes in Part II. 相似文献
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Experimental studies are conducted in order to elucidate the mechanisms of monoethanolamide responsible for synergism on lowering interfacial tension and decreasing loss due to adsorption on surface of reservoir sand and precipitation with multivalent cations in model oil/water/surfactants/brine systems. The interfacial tensions between solutions containing crude oil and monoethanolamide, petroleum sulfonates, or mixture of monoethanolamide and petroleum sulfonates at different ratios are studied without any alkali added in the solution. The results show significant synergic effect between monoethanolamide and petroleum sulfonates can reduce the interfacial tension to ultralow. Adsorption isotherms of monoethanolamide, petroleum sulfonates and mixture solution are determined to assess the effect of monoethanolamide on reducing the loss of petroleum sulfonates in formation. Static adsorption experiments indicate that the loss of petroleum sulfonates for adsorption and precipitation can be reduced on a great degree when monoethanolamide is mixed with petroleum sulfonates. The core-flooding tests show that the enhanced oil recovery with the formulation of surfactants of 0.3 wt% petroleum sulfonates and 0.2 wt% monoethanolamide can be increased by 26.6% without any alkali added in the flooding solution. 相似文献
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Györyová K. Kovářová J. Andogová E. Zeleňák V. Nour El-Dien F. A. 《Journal of Thermal Analysis and Calorimetry》2002,67(1):119-128
Zinc carboxylate complexes with N-donor ligands exhibit antimicrobial and antifungal effects. The preparation and thermal properties of complex compounds Zn(isobut)2 and Zn(isobut)2L(isobut=(CH3)2CHCOO–, L=papaverine — pap, phenazone — phen) are described in this paper. The newly synthesized compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods.During the thermal treatment it was found that the release of organicligands (pap, phen) was followed by pyrolysis of zinc(II) isobutyrate. (C3H7)2CO and CO2 were found as gaseous products and zinc oxide as the final product of thermal decomposition. Gaseous and solid products of thermal decomposition were confirmed by chemical analysis, IR spectra and X-ray powder diffraction.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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Carsten Dohmeier Dagmar Loos Hansgeorg Schnckel 《Angewandte Chemie (International ed. in English)》1996,35(2):129-149
By the end of the last century there were already the first indications of the possible existence of Al1 halides. However, it was only through the pioneering works of W. Klemm, who would have celebrated his 100th birthday on January 6, 1996, that detailed spectroscopic investigations became possible. Since the end of the 1970s the reactivity of AlX and GaX species in solid noble gases has been confirmed by numerous examples. In recent years formally monovalent Al and Ga species have been successfully synthesized on a preparative scale. In addition to the first halides, organometallic compounds with metal–metal bonds have been isolated and investigated with regard to their chemical properties. The fundamental importance of such species has been documented in this journal among others in the form of two highlight articles in which experimental and theoretical aspects have been examined with examples, and parallels and differences with respect to boron chemistry have been illustrated. This review is intended to give an account of the chronological development of this research area over the last few years, but an attempt is also made to categorize the experimental results achieved not only with respect to structure, thermodynamics, and reactivity, but also with the aid of quantum chemical calculations and by comparative considerations. 相似文献
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镍酶及其模型化合物的研究* 总被引:4,自引:0,他引:4
本文介绍5种镍酶即尿酶、镍氢化酶、一氧化碳脱氢酶/乙酰辅酶A合成酶、甲基辅酶M还原酶和超氧化歧化酶的结构和功能及其模型化合物的最新研究进展。 相似文献
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M. A. Abbady M. M. Kandeel Sh. H. Abdel-Hafez M.-A. M. Abou-Omar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1708-1725
3,3′-Diacetyloxy (2), 3,3′-dihydroxy (3), 4,4′-diamino (4), and 4-amino (5) diphenylselenide derivatives were prepared as new precursors for the title studies. Compound 6 was obtained by condensation of 4 with an appropriate aromatic aldehyde. Unsymmetrical diphenylselenides 7 and 8 were obtained by condensation of 4 and/or 5 with an aromatic aldehyde. Compound 7 undergoes facile condensation with the same aldehyde present in its arylidene moiety to yield 6, while condensation with another different aromatic aldehyde yielded unsymmetrical 4-arylideneamino diphenylselenide derivative 9. Oxidation of 6, 8, and 9 using lead tetra acetate and/or N-bromosuccinimide yielded symmetrical bis-(2-aryl benzoxazol-6-yl) (10), unsymmetrical 3′-hydroxy, 2-aryl benzoxazol-6-yl selenides (11), and 2-aryl benzoxazol-6-yl, 2′-aryl′ benzoxazol-6′-yl selenide derivatives (12), respectively. Compound 10 was prepared in one-pot unequivocal synthesis by fusion of 4 with the appropriate aromatic aldehyde, while 12 was prepared by fusion of 4 with two different aromatic aldehydes. In certain cases, 6 and 9 were heated on a direct flame until complete homogeneity afforded the corresponding 10 and 12. The structures of the synthesized compounds are based on physical data, IR, 1H NMR, 13C NMR, chemical means, and mass spectral data. Some of the synthesized compounds were biologically tested. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献