Influence of the Concentration of Ionic Acrylamide Copolymers,Ionic Strength,and Kind of the Electrolyte on the Thoms Effect

The influence exerted by the copolymer concentration, ionic strength, and kind of single- and multicharged ions on the reduced Thoms effect was examined for ionic acrylamide copolymers as additives reduciong the hydraulic resistance of turbulent aqueous-salt flows. Synergism and antagonism were detected for certain combinations of the polymer and electrolytes.     

Influence of Concentration and Molecular Characteristics of Copolymers of Acrylamide with Sodium Acrylate on the Thoms Effect in Oil-in-Water Emulsions

The effect of the concentration and molecular parameters of random copolymers of acrylamide and sodium acrylate on their performance as additives reducing the hydraulic resistance of turbulent flows in oil-in-water emulsions is quantitatively studied.     

Influence of the Reaction Medium on the Kinetics of Copolymerization of N-Vinylsuccinimide with Butyl Acrylate

Radical copolymerization of N-vinylsuccinimide with n-butyl acrylate in pyridine and the influence of donor characteristics of the solvent on the reaction kinetics were studied. The kinetics of copolymerization in various solvents (dichloroethane, dimethyl sulfoxide, and pyridine) were studied.     

Toms Effect in Model and Real Systems

Selected data on use of macromolecular compounds (polymers) as additives that diminish the hydraulic resistance of turbulent fluid flows (Toms effect) are presented. Theoretical and applied (concerning mainly oil production) aspects of the phenomenon are considered.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005, pp. 529–544.Original Russian Text Copyright © 2005 by Myagchenkov, Chichkanov.     

Superfast Responsive Ionic Hydrogels: Effect of the Monomer Concentration

A series of strong polyelectrolyte gels were prepared in aqueous solution, using the sodium salt of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) as the monomer and N,N'‐methylene(bis)acrylamide (BAAm) as a crosslinker. The gels were both prepared below (?22°C) and above (25°C) the bulk freezing temperature of the water, producing cryogels and hydrogels, respectively. The crosslinker (BAAm) content was set at 17 mol%, while the initial monomer concentration C_o was varied over a wide range. It was found that, at ?22°C, a macroscopic network starts to form at an initial monomer concentration of as low as 0.1 w/v%. In contrast to the conventional hydrogels formed at 25°C, the cryogels have a discontinuous morphology consisting of polyhedral pores of sizes 10⁰–10² μm. The cryogels exhibit superfast swelling properties, as well as reversible swelling–deswelling cycles in water and acetone. An increase in the initial monomer concentration from 2.5 to 10% further increases the response rate of the cryogels due to the simultaneous increase of the porosity of the networks.     

Toms Effect in Direct Crude Oil Emulsions as Influenced by the Stream Velocity and Concentration of Anionic Copolymers of Acrylamide

The major relationships in the Toms effect in direct crude oil emulsions differing in the dispersed phase concentration were studied on a modified turbulent rheometer with anionic copolymer of acrylamide as the polymer additive. The Toms effect was studied as influenced by the polymeric additive concentration and shear stress.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 506–511.Original Russian Text Copyright © 2005 by Myagchenkov, Chichkanov, Yakovenko.     

Toms Effect as Influenced by the Glass Capillary Length and Diameter

The degree of reduction of the hydraulic resistance was studied as influenced by the concentration of the anionic copolymer of acrylamide, geometric parameters of the contour, and turbulent flow velocity.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005, pp. 669–672.Original Russian Text Copyright © 2005 by Chichkanov, Myagchenkov.     

添加中低浓度离子液体[bmim][BF4]对吐温-20临界胶束浓度和胶束结构的影响

添加离子液体会对表面活性剂在水溶液中的聚集行为产生重要影响。本文研究了吐温-20在中低浓度离子液体四氟硼酸1-丁基-3-甲基咪唑鎓([bmim][BF_4])中的胶束化行为。随着[bmim][BF_4]浓度(cIL)从0增加到0.2mol·L~(-1),吐温-20的临界胶束浓度逐渐增大。相比cIL0.05mol·L~(-1),在cIL0.05mol·L~(-1)时加入[bmim][BF_4]使吐温-20临界胶束浓度增大得更加显著。吐温-20胶束聚集数随着离子液体浓度的增加而逐渐减小,这一结果也说明加入离子液体会对吐温-20胶束的生成有抑制作用。吐温-20胶束化热力学研究表明,吐温-20在不同浓度离子液体中的胶束化是熵、焓共同驱动,并具有熵-焓补偿性。随着离子液体浓度的增加,吐温-20胶束平均粒径和胶束微粘性均表现出先增大后减小的变化,在cIL=0.05mol·L~(-1)时达到最大值。     

Effect of the Medium on Fluorescence Parameters and Photostability of Porphyrins of Different Structure

Fluorescence and photostability against the action of UV irradiation of different porphyrins in benzene, DMF, and acetic acid media have been studied. The effect of the macroheterocycle structure on the conditions of its thermal decomposition under inert atmosphere has been investigated.     

Investigations of the Enhancer Effect of a High-Salt Concentration Medium on the Luminol Chemiluminescent Reaction

The enhancer effect of a high-salt concentration medium on the luminol chemiluminescence reaction catalyzed by either soluble or immobilized peroxidase has been investigated. Some widely used salts were tested at high concentration (up to 3 mol L): potassium chloride, sodium chloride, ammonium sulfate and calcium chloride. The magnitude of the light intensity enhancement depends on the nature of the salt and on the form of the peroxidase, i.e. free in solution or immobilized. The enhancement is observed whether the catalyst of the chemiluminescence reaction is peroxidase or ferricyanide. Both the enhanced or nonenhanced luminol chemiluminescence spectra have a maximum wavelength emission at around 425 nm. The results reported in this study are in favor of an action of the salts on the nonenzymatic steps of the luminol chemiluminescence reaction rather than a modification of the enzymatic process.     

Influence of Ionic Surfactants on Tetrabromophenylfluorone Ionic Associates

Stability constants of ionic associates of a hydroxyxanthene dye, tetrabromophenylfluorone, with a series of organic cations were determined spectrophotometrically. The possibility of quantitative determination of anionic surfactants (alkyl sulfates) in an aqueous solution in the form of a dye anion associate with tetrabutylammonium cation was considered.     

Influence of Ionic Strength, pH, and SDS Concentration on Subunit Analysis of Phycoerythrins by SDS-PAGE

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is often used for subunit analysis of proteins, but it is not efficient to make the α- and β-subunits of phycoerythrins separated by normal SDS-PAGE. In this research, subunit components and subunit molecular weights of four purified phycoerythrins were analyzed by SDS-PAGE. Four factors including Tris concentration, pH, ammonium persulfate (APS), and SDS concentration were studied for their effects on SDS-PAGE of phycoerythrins. It showed that these factors can influence the separation of α- and β-subunits, electrophoresis effect of γ-subunits, apparent molecular weights of subunits, and mobility of marker proteins. The α- and β-subunits separated better in the case of lower SDS concentration, lower Tris concentration, higher pH, and/or lower APS addition in separating gels. The molecular weights of α- and β-subunits increased when Tris concentration increased in a certain range. It can be concluded that factors critical to subunit analysis by SDS-PAGE are SDS concentration and ionic strength, both of which are related to critical micelle concentration of SDS and ratio of SDS monomer to micelle in SDS-PAGE system. The ratio is postulated to influence SDS-PAGE by influencing the amount of SDS bound to polypeptides and shapes of polypeptide–SDS complexes.     

Influence of Emulsifiers on Acrylate Latex Blends

The poly(methyl methacrylate/butyl acrylate/acrylic acid) [P(MMA/BA/AA)] and poly (styrene/butyl acrylate/acrylic acid) [P(St/BA/AA)] latexes were synthesized using the emulsifier octylphenol polyoxyethylene(10) ether (OP-10) and ammonium sulfate allyloxy nonylphenoxy poly(ethyleneoxy)(10) ether(DNS-86). The optimum amount of OP-10 and DNS-86 was 1.5% and 2.5% respectively. The P(MMA/BA/AA) and P(St/BA/AA) latex containing 1.5% OP-10 or 2.5% DNS-86 were blended pairwise. The performances of latex blends and parent latexes as a function of emulsifiers content in parent latexes were determined. The results indicated that the stability of latex blends is favorable, and particle size distribution was more uniform and thermal stability was improved after blending.     

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚;全氟烷基丙烯酸酯;无皂乳液;离子型共聚单体     

游离125I与血浆蛋白的结合及其对血药浓度测定的影响

通过体内、外实验, 研究了游离125I与血浆蛋白的结合及其在三氯乙酸(TCA)沉淀后的沉淀百分率, 并与125I-RGD-Sak在SD大鼠中不同时间血药浓度的结果进行了比较. 结果表明, 游离125I能与血浆蛋白结合, 并为TCA所沉淀, 且在一定范围内, 游离125I与血浆蛋白结合后的沉淀百分率与温育时间及游离125I的活度无关. 体内、外实验中, 游离125I与血浆蛋白结合后的沉淀百分率分别为(1.26±0.14)%及(1.38±0.33)%. 沉淀物中含有吸附在沉淀物表面的游离125I, 该吸附需要用TCA沉淀2~3次才能去除. 采用125I核素示踪法进行生物类制品的药代动力学研究时, 应对游离125I的影响进行校正.     

POP-290阻燃剂对丙烯酸酯光固化涂料的影响

制备了双酚A环氧丙烯酸酯(EA)/阻燃剂(POP-290,聚合物聚醚多元醇)/活性单体阻燃UV涂料,主要考察了不同用量的阻燃剂对丙烯酸酯UV涂料的阻燃性能和光固化的影响.研究结果表明,阻燃剂的使用提高了UV涂料体系的固化速度、凝胶含量及玻璃化转变温度(T_g).当m(EA):m(活性单体)=4:1,POP-290含量为7%(质量分数)时,水平燃烧等级达到FH-1,LOI从原来的21提高到26.     

Effect of Ionic Concentration on Drug Release from Polyelectrolyte Hydrogel Carriers Analyzed via Triphasic Mechanism Model

In different parts of the gastrointestinal tract, the rate of drug release from polyelectrolyte hydrogel tablets is highly affected by variance of ionic concentration. This research aims at revealing clearly how the drug release from a hydrogel matrix is affected by ionic concentration of external solution through the finite element simulation and triphasic mechanism model. The coupled relationship of the motions including the polyelectrolyte hydrogel swelling, the water flow and the ion diffusion, is illustrated in the present work. In order to simulate the drug controlled release from a swollen polyelectrolyte hydrogel carrier, the mathematical model was built on the basis of the multiphasic theory of polyelectrolyte hydrogels. Finally, the reliability of the simulation method was verified qualitatively by experimental results. The results reveal that when the initial concentration of fixed anions of polymer network is higher than the concentration of free anions in the external solution, the drug release rate increases with increasing the ionic concentration of the external solution. The research is helpful for the optimal design of oral drug release in gastrointestinal tract.     

Thoms Effect as Influenced by the Concentration and Molecular Parameters of the Cationic Copolymer of Acrylamide

The Thoms effect observed with water-soluble cationic copolymer of acrylamide was studied in relation to the concentration, molecular weight, and molecular weight polydispersity of the polymeric additive, with its composition and composition polydispersity being constant.     

Influence of the Use of an Ionic Liquid as Pre-Hydrodistillation Maceration Medium on the Composition and Yield of Cannabis sativa L. Essential Oil

Cannabis sativa L. is a multi-purpose crop, whose resilience, adaptability and soil-enriching properties make it a low-impact production. In the last years, the cultivation of the “industrial” hemp varieties (THC < 0.2%) has been promoted by many Countries, opening a whole new market of hemp-derived products, such as its essential oil (EO). Its distillation might represent an effective method to exploit a residue of the hemp fiber production (flowers), complying with the guidelines of the circular economy. In the present work, different concentrations of an ionic liquid (IL; 1,3-dimethyl-1H-imidazol-3-ium dimethylphosphate) have been studied as a pre-hydrodistillation maceration medium. The EO yields have been evaluated, and their compositions have been analyzed by GC-EIMS. The use of 100% and 90% IL concentrations gave a hydrodistillation yield increment of 250% and 200%, respectively. The 200% yield increase was maintained when the 100% IL was recycled after the hydrodistillation. The lower IL concentrations incremented the cannabinoid and oxygenated sesquiterpene contents, while the opposite was true for sesquiterpene hydrocarbons. The proposed IL-enhanced hydrodistillation medium applied to hemp, studied for the first time in the present work, might be used to both (i) noteworthy increment the hydrodistillation yield and (ii) modulate the obtained EO composition based on the desired final product.     

Influence of the Inductive Effect of Substituents on the NMR Parameters of Phosphorylated Alkenes

The inductive effect model was used to adequately describe and predict the P-H coupling constants in the ¹H NMR spectra of phosphorylated alkenes. A procedure was developed for determination of the steric structure of phosphorylated alkenes from the ¹H NMR spectra of one of the isomers.