新型羟基磺基甜菜碱/聚丙烯酰胺二元复合体系性能评价

新型羟基磺基甜菜碱表面活性剂与相对分子质量为2 500万的聚丙烯酰胺进行复合,测定体系的界面张力、黏弹性及乳化性能。结果表明,新型羟基磺基甜菜碱表面活性剂在浓度2.16 mmol/L时,表面张力33.39 m N/m,且乳化性能较好,具有较好的表面活性剂性能。相比于单独的表面活性剂,二元复合体系使溶液的临界胶束浓度增大,且界面张力也升高。当表面活性剂浓度为1.3 g/L,聚合物浓度为0.5 g/L时,体系的界面张力达到最低。聚合物的加入能显著降低体系的粘弹性,且随着聚合物浓度的增加,出现黏度最大值的表面活性剂的浓度越低。当表面活性剂水溶液质量浓度1.3 g/L,聚合物浓度1.5 g/L时,体系乳化性能最佳,实验表明,在低渗透岩心中,可以提高采收率5.78%。     

新型羟基磺基甜菜碱/聚丙烯酰胺二元复合体系性能评价

新型羟基磺基甜菜碱表面活性剂与相对分子质量为2 500万的聚丙烯酰胺进行复合,测定体系的界面张力、黏弹性及乳化性能。结果表明,新型羟基磺基甜菜碱表面活性剂在浓度2.16 mmol/L时,表面张力33.39 m N/m,且乳化性能较好,具有较好的表面活性剂性能。相比于单独的表面活性剂,二元复合体系使溶液的临界胶束浓度增大,且界面张力也升高。当表面活性剂浓度为1.3 g/L,聚合物浓度为0.5 g/L时,体系的界面张力达到最低。聚合物的加入能显著降低体系的粘弹性,且随着聚合物浓度的增加,出现黏度最大值的表面活性剂的浓度越低。当表面活性剂水溶液质量浓度1.3 g/L,聚合物浓度1.5 g/L时,体系乳化性能最佳,实验表明,在低渗透岩心中,可以提高采收率5.78%。     

石油磺酸盐复合体系界面张力影响因素研究

在三元复合体系中油水形成的界面张力值对驱油效率影响很大,界面张力值越低驱油作用越好。本文以石油磺酸盐、聚丙烯酰胺和碳酸钠复合驱油体系在大庆油田下的界面张力为研究对象,采用旋滴法测量,研究了组分含量、污水矿化度及金属离子浓度对复合体系界面张力的影响,确定了经济的浓度范围。结果表明,石油磺酸盐浓度为0. 025%～0. 4%时该三元体系界面张力均可达到超低10-3m N/m数量级;聚丙烯酰胺浓度过高会影响复合体系界面张力值,适宜浓度为500～1000 ppm;碳酸钠浓度的增加有利于降低复合体系界面张力值;在钙镁离子浓度低于1500 mg/L、钠离子低于6000 mg/L矿化度的模拟污水中,该复合体系界面张力仍可达到超低值。     

丙烯酰胺聚合物与发泡剂对油水界面性质及乳状液稳定性的影响

用界面张力仪、表面黏弹性仪和Zeta电位仪研究了胜利埕东油田聚合物强化泡沫复合驱中聚合物和/或发泡剂质量浓度对油水界面特性及乳状液稳定性的影响.结果表明,随聚合物质量浓度增加,模拟水与原油模拟油间油水界面张力、界面剪切黏度和油滴表面的Zeta电位绝对值增大;而随发泡剂质量浓度增加,模拟水与原油模拟油间的界面张力降低,界面剪切黏度有所增加,但变化幅度很小,油滴表面的Zeta电位绝对值增大;原油模拟油与含聚合物和发泡剂的模拟水间所形成的W/O乳状液稳定性随聚合物和/或发泡剂质量浓度增加而增强.     

烷基苯磺酸盐表面活性剂的界面性能研究

通过合成碳链长度不同的四种烷基苯磺酸盐表面活性剂,研究了复配表面活性剂浓度、Na2CO3、NaCl浓度、聚丙烯酰胺浓度对油/水界面张力的影响。结果表明：复配表面活性剂浓度在0.1%～0.3%范围内,界面张力较低;Na2CO3浓度为0.6%（wt）时,界面张力较低,且最低界面张力达到超低（3.1×10^-3mN/m）;NaCl的最佳浓度为0.4%;复合体系的超低界面张力是由表面活性剂和碱共同作用产生的,聚合物的加入对体系界面张力的影响甚小。     

活性聚合物表面扩张黏弹性能研究

利用界面扩张流变仪考察了活性聚合物(简称"聚表剂")溶液的表面扩张黏弹性质,并对比了相同质量分数时其与HPAM溶液表面扩张黏弹性质的差异。实验结果表明,"聚表剂"溶液在较低浓度时,溶液扩张模量和相角随频率变化幅度很小,随着溶液浓度的增加,频率对扩张模量和相角的影响程度增大。随着振幅增加,"聚表剂"溶液的表面扩张模量增加,在振幅大于气泡面积的8%以后,表面扩张模量趋于平稳。"聚表剂"溶液的扩张模量随其浓度的变化通过一个极大值,而相角随着"聚表剂"浓度的增大而增大。HPAM溶液扩张模量明显低于相同质量分数的"聚表剂"溶液,且随频率变化幅度很小,而"聚表剂"溶液扩张模量随频率变化幅度很大。     

丙烯酰胺/2-丙烯酰胺-2-甲基丙磺酸/N-辛基丙烯酰胺共聚物与石油磺酸盐的相互作用研究

通过研究丙烯酰胺/2-丙烯酰胺-2-甲基丙磺酸/N-辛基丙烯酰胺共聚物(HPPS)与石油磺酸盐复配体系的表观黏度、表/界面活性及吸附性质,讨论了两者的相互作用。结果表明,石油磺酸盐与质量浓度1.5 g/L聚合物HPPS复配溶液的表观黏度随着石油磺酸盐质量浓度的增大而上升,在其质量浓度为2.0 g/L时复配溶液表观黏度达到最大值后迅速下降。石油磺酸盐质量浓度低于0.5 g/L时复配溶液的表面张力值低于单独的石油磺酸盐溶液;之后则高于单独的石油磺酸盐溶液。复配溶液与胜利油田原油的界面张力高于单独的石油磺酸盐溶液,但最低值仍可达到1×10-2mN/m。聚合物HPPS与质量浓度为2.0 g/L的石油磺酸盐的复配溶液中,石油磺酸盐在地层砂上的静态吸附量随着聚合物HPPS质量浓度的增大而显著增大,当聚合物质量浓度为3.0 g/L时静态吸附量达到最大值。     

硅氟两亲聚合物在柴油/水体系中的分水效能及机理

对4种含氟链段聚合度不同的硅氟聚合物在柴油/水体系中的分水效能进行了评价,并通过界面张力和界面黏弹性研究了其分水机理。结果表明,随着含氟链段聚合度的增加,其油水分离时间先减小后增大。含氟单体平均聚合度为16的聚合物质量浓度为0.2g/L时,在23s内实现柴油/水的完全分离。界面张力不是影响分水效能的主要因素,该类聚合物主要通过降低界面膜黏弹性实现有效分水。     

炸药用胶粘剂溶液的黏弹性研究

以氟橡胶(F2602)为胶粘剂、乙酸乙酯为溶剂,制备聚合物粘接炸药(PBX)用胶粘剂溶液。可降低感度的胶粘剂之黏弹性是影响PBX使用的重要因素。采用光学视频接触角测量仪通过振荡法可测得不同浓度、不同频率之胶粘剂溶液的黏弹性参数[如模量、绝对模量、储能模量、损耗模量和损耗因子(tanθ)等]和界面张力,利用Origin Pro软件拟合可得到胶粘剂溶液的黏弹性参数与频率或浓度的关系式。研究结果表明:上述关系式在预测非挥发性胶粘剂溶液时效果良好,其计算值与实测值基本吻合,但在预测挥发性胶粘剂溶液时有一定误差,而溶剂的易挥发性是试验误差的主要来源;对移取微量溶液用针管表面进行改性或选择其他适宜材质的针管,将胶粘剂溶液浸泡在适宜的惰性溶剂中测定黏弹性,均有利于减小试验误差。     

羧酸盐表面活性剂与两亲聚合物相互作用研究

根据黏度和表面张力的测定数据研究了羧酸盐表面活性剂(HF-E)与两亲聚合物的相互作用,结果表明,HF-E/两亲聚合物混合溶液的表观黏度随HF-E质量浓度的增加先升高后下降;两亲聚合物的质量浓度越大,HF-E/两亲聚合物混合溶液表面张力越高;随着水的矿化度的升高,HF-E/两亲聚合物混合溶液的表观黏度先略有增加,到一定值后反而降低,而表面张力则随矿化度的增加而降低;温度升高,HF-E/两亲聚合物混合溶液的表观黏度随之降低而其与大庆模拟油间的界面张力则升高。优化后的高黏度低界面张力二元体系配方为HF-E和两亲聚合物的质量浓度分别为3和1.5 g·L-1;此外,还加入质量浓度为1 g·L-1的烷基醇酰胺(NS)。     

Adsorption Behavior of Fatty Alcohol Ether Sulfonate at Different Interfaces

The equilibrium surface tension, dynamic surface tension, and interfacial tension (IFT) of fatty alcohol ether sulfonates (C_mE_nSO) were measured to investigate their adsorption behavior. The effect of NaCl and CaCl₂ concentrations on the IFT was also studied. The results showed that the number of EO units has no significant effect on the critical micelle concentration (CMC) and CMC decreases with increasing the length of the hydrophobic group. The surface tension at the CMC increases with the increase of the number of EO units and the length of the hydrophobic group. At dilute surfactant concentration, the adsorption process for C_mE_nSO is controlled by diffusion; at higher concentration, it becomes a mixed diffusion‐kinetic adsorption mechanism. The IFT between C_mE_nSO solution and dodecane remains around 10^?1 mN/m over a wide range of electrolyte concentrations (NaCl concentration from 25 to 210 g/L, CaCl₂ concentration from 0.1 to 10 g/L).     

Interfacial Dilational Rheology of Sodium Lauryl Glycine and Mixtures with Conventional Surfactants

Amino acid-based surfactants are environmentally friendly surfactants, which have aroused increasing interest. In the application of amino acid-based surfactants, they are often compounded with other kinds of surfactants to obtain formulations that meet certain requirements. Herein, sodium lauroyl glycinate (C12-Gly-Na) was selected as a representative amino acid-based surfactant to compound with an anionic surfactant (sodium dodecyl sulfate [SDS]), a cationic surfactant (dodecyl trimethyl ammonium Bromide), and a nonionic surfactant (Triton X-100: p-octyl polyethylene glycol phenyl ether). Surface tension measurements and interfacial dilational rheological experiments were performed to study the interfacial behaviors of C12-Gly-Na and its mixtures. The results show that mixture systems have better interfacial activity than individual C12-Gly-Na and there is an obvious synergy between C12-Gly-Na and C12TAB under strong electrostatic attraction. Thus, the C12-Gly-Na/C12TAB mixture shows lower critical micelle concentration (CMC) and γ_CMC and higher dilational modulus than the individual surfactants. Besides, the film formed by the C12-Gly-Na/C12TAB mixture has higher viscoelasticity than single C12-Gly-Na and its mixtures with SDS and TX-100. With the increase of bulk concentration, the dilational moduli of C12-Gly-Na, C12-Gly-Na/SDS, and C12-Gly-Na/TX-100 run through two maxima, while, due to stronger electrostatic attraction, only one maximum appears in the C12-Gly-Na/C12TAB system. The study of the interfacial properties of amino acid surfactant and its mixtures with other surfactants provides a theoretical foundation for potential applications in cosmetic, food processing, and daily chemical industries.     

ZnFe anomalous electrodeposition:: stationaries and local pH measurements

The kinetics of ZnFe codeposition was investigated in acid solutions. The effects of solution composition and pH were analyzed. Inhibition of H⁺ reduction and Fe deposition occurs with increasing Zn⁺⁺ concentration in sulfate solution. An activation of Zn deposition is also observed. Increasing pH causes Zn deposition activation during ZnFe codeposition. The anomalous codeposition is also favored in chloride medium. When alloy deposition becomes the main process, the interfacial pH is governed by the individual metal deposition that controls the kinetic behavior. The interfacial pH increases during separate Fe deposition, meaning that it occurs with simultaneous consumption of H⁺. Individual Zn deposition brings about an H⁺ inhibition. A correlation between the codeposition behavior of ZnFe and ZnNi in sulfate and chloride solutions suggests that the prevailing cathodic reaction governs the interfacial pH. Anomalous codeposition process does not seem to be associated with a saturation of any thermodynamic species at the electrode surface. It can only be described by kinetic arguments.     

Interfacial Tension Studies of N,N‐Dialkyl Amides

Abstract

The interfacial tension (IFT) of 1 M solutions of N,N‐dialkyl amide in n‐dodecane against water and nitric acid has been measured at 303 K. Ten amides, namely, dibutyl hexanamide (DBHA), diisobutyl hexanamide (DiBHA), dibutyl octanamide (DBOA), dihexyl hexanamide (DHHA), dibutyl dodecanamide (DBDA), di n‐octyl butanamide (DOBA), diisooctyl butanamide (DiOBA), di n‐octyl isobutanamide (DOiBA), di n‐hexyl octanamide (DHOA), and di n‐octyl hexanamide (DOHA) were synthesized and used. The effect of concentration of DOHA on IFT against 3 M nitric acid was also studied. It was observed that the introduction of branching in an amide on either the acyl or the nitrogen side increases the IFT over its straight chain analogue, as in the case of DiOBA, DOiBA, and DiBHA. Increasing the carbon chain length on the acyl side, keeping the total carbon number constant, was found to increase the IFT considerably. Increasing the concentration of the amide resulted in a decrease in the IFT values, due to the lowering of the concentration of hydrophobic diluent. An increase in the uranium loading of the organic phase in the case of 1 M DOHA, was found to increase the IFT.     

INTERFACIAL COMPOSITION OF MICROEMULSIONS: MODIFIED SCHULMAN-BOWCOTT MODEL

The interfacial composition of oil-external microemulsions formed with sodium stearate, pentanol, brine and various oils (octane, dodecane and hexadecane) was determined in terms of moles of alcohol per mole of surfactant present at the interface (niⁱ_a/n_3,) using a modified three compartment Schulman-Bowcott model. The modified model takes into account the solubility of pentanol in aqueous and hydrocarbon phases. For a constant brine/surfactant ratio, it was found that the value of (niⁱ_a/n_3,) was highest for dodecane containing microemulsion which corresponded to the maximum solubilization of brine in this microemulsion at optimal salinity. This behavior is explained on the basis of chain length compatibility in microemulsions. The optimal salinity for solubilization increased with the chainlength of oil.     

Swelling behavior of sulfonated polyacrylamide nanocomposite hydrogels in electrolyte solutions: comparison of theoretical and experimental results

Nanocomposite hydrogels were prepared by cross-linking of aqueous solutions of sulfonated polyacrylamide/sodium montmorillonite with chromium triacetate as ionic cross-linker. The effect of montmorillonite content on equilibrium swelling in NaCl and CaCl₂ solutions, ultimate storage modulus and effective cross-link density was evaluated. The limiting storage modulus of the nanocomposite (NC) hydrogels dropped by increasing montmorillonite content up to 1,000?ppm, and then it increased by further montmorillonite loading. A mechanism is proposed for the formation of PAMPS/Na⁺-MMT/Cr³⁺ NC hydrogels. According to this mechanism, the drop in limiting storage modulus of the NC gels at low Na⁺-MMT concentration is due to ionic interactions between the negative layers of sodium montmorillonite and Cr³⁺, leading to decreased cross-link density. However, the increase of the limiting storage modulus of the NC gels at high clay concentration results from the strong interactions between the polyacrylamide chains and clay platelets. The equilibrium swelling ratio of the NC networks decreased with increase of montmorillonite content in both aqueous NaCl and CaCl₂ solutions. In addition, the experimental swelling data of these NC hydrogels were described by a modified Flory?CRehner theory. The modified model was sensitive to montmorillonite concentration and it described adequately the swelling data for NC gels in NaCl solutions. Nevertheless, theoretical predictions showed some deviations from experimental results for swelling of NC hydrogels in CaCl₂ solutions.     

A numerical model for elastic modulus of concrete considering interfacial transition zone

The effect of interfacial transition zone on mechanical properties of concrete has been found to be significant, thus the interfacial transition zone should be considered in the analysis for better estimation of elastic modulus of concrete. However, it is difficult to estimate elastic modulus of concrete practically using simple models proposed so far. In this study, a numerical concrete model that adopts three-phase model and finite element with material discontinuity was proposed to analyze concrete with complex interface in three dimensions. The validity of the proposed model was verified by comparing the calculated elastic moduli of concrete with those obtained from experiments. The effect of interfacial transition zone on elastic modulus of concrete with either low or high w/c was also investigated. The analysis results suggest that careful selection of characteristics for interfacial transition zone should be made for the accurate estimation of elastic modulus of concrete.     

Rheological properties of polystyrene and poly(methyl methacrylate) blends

Rheological properties of the polystyrene (PS) and poly(methyl methacrylate) (PMMA) blends were studied by Advanced Rheometric Expansion System (ARES). Storage modulus and loss modulus of the PS and PMMA blends were measured, and the interfacial tension of the PS and PMMA blends were obtained with various emulsion models by using the storage modulus and loss modulus of the blends. The value of interfacial tension estimated from the Palierne emulsion model was found to be 2.0 mN/m. Also, the interfacial tension between PS and PMMA was calculated by a theoretical model. The values of interfacial tension of the PS and PMMA blends obtained by the experiment and theoretical model were found to be in good agreement.     

Über den Einfluß des kolloichemischen Aufbaus von Trägergrundlagen auf die cutane Aufnahme eines Pharmakons. I. Entwicklung von potentiellen Transportsystemen auf der Basis von Kohlenwasserstoff als Ölkomponente

Influence of the Colloidal Structure of Vehicles on the Percutaneous Drug Absorption. I. Development of Potential Transport Systems with Hydrocarbon as Oil Component In this part the development and colloidal differentiation of some model systems is presented containing dodecane as oil, water and polyoxyethylene(7)laurylether as nonionic surfactant. In specific concentration ranges mixtures of water and surfactant give stable solutions being micellar or inverse-micellar, and two mesophases, a gel with hexagonal structures (phase M) and a region with a onedimensional lamellar lattice (phase N). Dodecane being the third component will be integrated within the unpolar regions of the structures, enlarging the diameter of the rods in the case of phase M and the thickness of lipid bilayer in the case of phase N. The formation of emulsions, creams and gels is highly depending on the presence of the hydrocarbon. Their different structures will be described, proposing a specific three-phase structure of the creams and a cubic lattice in the case of the isotropic, visco-elastic gel.     

Diffusion in aqueous polymer solutions

The diffusion of Direct Blue 76 dye in aqueous dilute polymer solutions was studied using the capillary method. The polymer systems studied included dilute solution of carboxymethyl cellulose, poly(ethylene oxide), and polyacrylamide. It was found that the diffusion coefficient of Direct Blue 76 in carboxymethyl cellulose is higher than that in pure water, while in polyacrylamide and poly(ethylene oxide) solutions the value is lower than that in pure water. The diffusion coefficient of Direct Blue was found to decrease with increasing polymer concentration in case of poly(ethylene oxide) and polyacrylamide, while in case of carboxymethyl cellulose the diffusion coefficient increases with polymer concentration. The effect of temperature on the diffusion coefficient of Direct Blue 76 in the three polymers was found to obey the Arrhenius equation. The activation energy for diffusion of Direct Blue 76 in water, poly(ethylene oxide), polyacrylamide, and carboxymethyl cellulose was found to be 4.38, 7.7, 5.44, and 5 kcal, respectively, for polymer concentration of 0.25 g/l.