共查询到20条相似文献,搜索用时 218 毫秒
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近年来,油田采油过程对驱油材料的性能提出了更高的要求,使用纳米材料是从微观角度提升驱油剂性能的重要方法.研究表明,对纳米材料进行改性处理,如表面接枝改性、构造核-壳分子结构等,以及将纳米材料与其他驱油材料(如聚合物、表面活性剂等)复配,可从降低油水界面张力、乳化原油降低原油粘度、改善岩石表面润湿性、稳定泡沫等方面推动原... 相似文献
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乳状液液膜体系中助表面活性剂LA的作用及其应用研究 总被引:9,自引:1,他引:8
本文提出了通过降低乳水界面张力来改善乳液分散的新途径,在一定程度上克服了依靠提高机械搅拌速度,来改善乳液分散效果时引起的乳液稳定性降低这一不良影响。研制了一种命名为LA的助表面活性剂,将其用于液膜体系可有效地降低乳水界面张力,极大地改善乳液的分散,提高液膜的稳定性,在液膜除酚试验中获得了良好的效果。 相似文献
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本文提出了通过降低乳水界面张力来改善乳液分散的新途径,在一定程度上克服了依靠提高机械搅拌速度,来改善乳液分散效果时引起的乳液稳定性降低这一不良影响。研制了一种命名为LA的助表面活性剂,将其用于液膜体系可有效地降低乳水界面张力,极大地改善乳液的分散,提高液膜的稳定性,在液膜除酚试验中获得了良好的效果。 相似文献
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以矿物油、表面活性剂、疏水纳米SiO2为原料,采用机械乳化法制备了含纳米SiO2水包油型乳液。通过响应曲面实验得出SiO2含量是影响乳液稳定性的主要因素,并在此基础上系统地研究了疏水纳米SiO2对乳液稳定性及特性的影响。结果表明:当固体颗粒含量达到一定时,才能形成稳定的乳液,其形状与大小随着颗粒含量的增加而发生改变;与传统乳液相比,含固体颗粒乳液具有更好的热稳定性。其次,采用荧光显微镜、界面张力、界面流变等测试手段揭示了疏水颗粒稳定水包油型乳液的相应机制。结果表明:疏水纳米SiO2吸附于油水界面改变了界面膜强度与结构,并与表活剂产生协同作用降低了油水界面张力,从而使乳液更加稳定。 相似文献
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双子表面活性剂具有较低的临界胶束浓度、降低水溶液表面张力或者水油之间界面张力的性能更强、更好的水溶性等优点。这些优良性能使其具有良好的应用潜力。本文介绍了双子表面活性剂的性能、合成以及应用等现状,表明这种表面活性剂具有重要的实用价值。 相似文献
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表面活性剂对液膜分离传质性能的影响 总被引:3,自引:0,他引:3
研究了不同表面活性剂组成的液膜体系在分离过程中的传质、溶胀和渗透等性能,分别考查了聚胺型表面活性剂L-113A和LMA-1及酯型表面活性剂Span80对含P204载体液膜体系迁移镧(Ⅲ)的影响,以及L—113A、L—113B和EM-301对无载体液膜体系富集氨氮的影响.实验表明,因表面活性剂不同,造成乳状液膜体系在分离富集镧或氨氮时,分离传质性能相差较大,LMA—1—P204-煤油的液膜体系对镧具有最大的迁移能力。迁移率97.4%;而L-113A-膜相添加剂-煤油的液膜体系对氨氮的溶解渗透能力最大。迁移率为86.4%.另外,对因表面活性剂结构不同而造成油水界面黏度的差异以及对传质速率的影响,从乳状液膜和自组装双分子液膜等方面进行了探讨. 相似文献
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液膜用高分子表面活性剂性能研究 总被引:7,自引:2,他引:5
本文介绍液膜用高分子表面活性剂PSN_(-89414)的性能,通过界面张力测定,用表面活性剂分子在界面上吸附理论导出公式求得Span80,PSN_(-89414)的界面吸附平衡常数K_(s)及S_(sf)的数值,结果表明,K_(s)、S_(sf)数值愈大的表面活性剂制得乳状液愈稳定,液膜溶胀愈小。PSN_(-89414)的W/O/W乳状液体系用于稀土分离,速度快,从浓度1.2g/L的稀土溶液浓集到103g/L。 相似文献
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S. B. Aidarova K. B. Musabekov Z. B. Ospanova M. Guden 《Journal of Materials Science》2006,41(13):3979-3986
The lifetime of water solution foams of sodium dodecylsulfate (DDS, low molecular weight surfactant) and sodium carboxymethylcellulose
(SCMC, polyelectrolyte) and their binary mixtures was experimentally investigated. The effects of ionic strength and acidity
on the foam life were also determined. In binary solutions, a synergic effect of DDS and SCMC on the surface tension reduction,
most likely resulting from the interaction of the surfactant with polymer, was found. The addition of NaCl into solution or
increasing the ionic strength was found to decrease the surface tension and reduce interfacial mobility, hence increased foam
lifetime. The relatively low lifetime of binary solution foams in acidic medium was attributed to the reaction between SCMC
and acid, which resulted in relatively small reductions in the viscosity and consequently lowered the solution viscosity. 相似文献
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Surface tension of aqueous lithium bromide with heat/mass transfer enhancement additives: the effect of additive vapor transport 总被引:1,自引:0,他引:1
Heat/mass transfer enhancement additives used in aqueous lithium bromide absorption chillers are surfactants that lower the surface tension of the working fluid. It has long been speculated that the surface tension characteristics are a key to the enhancement but the point is controversial because some surfactants do not provide enhancement. In the present study, the surface tension of aqueous lithium bromide was measured, with and without various surfactant additives, using a drop weight method. Measurements were also made on water, with and without an additive. The results provide new information that clarifies several confusing aspects of the literature data. The major result is the realization that the surface tension of aqueous lithium bromide is strongly affected by the presence of surfactant vapor around the liquid interface. This apparently explains the large differences in surface tension data found in the literature since no previous studies mentioned the importance of the vapor conditions. 相似文献
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The flow of two superposed viscous fluid layers in a two-dimensional channel confined between a plane and a wavy or indented
wall is studied by analytical and numerical methods at arbitrary Reynolds numbers. The interface between the two fluids may
exhibit constant or variable surface tension due to an insoluble surfactant. The flow is computed from a specified initial
condition using the immersed-interface method on a curvilinear grid constructed by conformal mapping. The numerical simulations
illustrate the effect of geometrical nonlinearity and reveal that inertia may increase or decrease the amplitude of the interface
profile at steady state depending on the flow parameters. Increasing either the Reynolds number or the wall amplitude above
a certain threshold value provokes flow instability and overturning of the interface. In the Appendix, a linear perturbation
analysis is performed for arbitrary Reynolds numbers on the assumption of small-amplitude sinusoidal undulations, and results
for the amplitude and phase shift of the interfacial and surfactant concentration wave are documented for a broad range of
flow conditions. It is found that inertia may have a mixed effect on the deformation and phase shift, while the surfactant
promotes the deformation of the interface under most conditions. 相似文献
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Takagi S Ogasawara T Matsumoto Y 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2008,366(1873):2117-2129
It is well known that a bubble in contaminated water rises much slower than one in purified water, and the rising velocity in a contaminated system can be less than half that in a purified system. This phenomenon is explained by the so-called Marangoni effect caused by surfactant adsorption on the bubble surface. In other words, while a bubble is rising, there exists a surface concentration distribution of surfactant along the bubble surface because the adsorbed surfactant is swept off from the front part and accumulates in the rear part by advection. Owing to this surfactant accumulation in the rear part, a variation of surface tension appears along the surface and this causes a tangential shear stress on the bubble surface. This shear stress results in the decrease in the rising velocity of the bubble in contaminated liquid. More interestingly, this Marangoni effect influences not only the bubble's rising velocity but also its lateral migration in the presence of mean shear. Together, these influences cause a drastic change of the whole bubbly flow structures. In this paper, we discuss some experimental results related to this drastic change in bubbly flow structure. We show that bubble clustering phenomena are observed in an upward bubbly channel flow under certain conditions of surfactant concentrations. This cluster disappears with an increase in the concentration. We explain this phenomenon by reference to the lift force acting on a bubble in aqueous surfactant solutions. It is shown that the shear-induced lift force acting on a contaminated bubble of 1mm size can be much smaller than that on a clean bubble. 相似文献
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《Composites Part A》2007,38(3):771-778
Continuous M40J carbon fiber reinforced aluminum–magnesium alloy composite wires have been fabricated using ultrasonic infiltration. The infiltration phenomenon is examined from the viewpoint of acoustic cavitation. The ease of infiltration of the molten alloys was found to be proportional to the maximum intensity of the acoustic cavitation. The ease of infiltration and the intensity were enhanced by the addition of surfactant elements into the molten aluminum. Thus, a decrease in surface tension caused an increase in the generation of acoustic cavitation thereby resulting in infiltration. Therefore, the generation of the acoustic cavitation is an infiltration controlling factor during the use of ultrasonic vibration. 相似文献
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M. A. Anisimov E. E. Gorodetsky A. J. Davydov A. S. Kurliandsky 《International Journal of Thermophysics》1992,13(5):921-928
The interfacial tension of a liquid-liquid interface in the critical region has been obtained as a function of the surfactant concentration on the basis of the Landau-Ginzburg model for critical phenomena. It is shown that surfactants may reduce significantly the interfacial tension in addition to the well-known near-critical reduction. 相似文献
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This paper reports a novel optofluidic sensor for measuring dynamic interfacial tensions. The field of optofluidics utilizes both microfluidics and micro-optics. Thus, our sensor consists of a microfluidic network and an optical detection system. The sensor is able to measure both surface tension and liquid/liquid interfacial tension. In the case of surface tension measurement, the liquid sample is introduced into a main channel, while air is injected through a T-junction. In the case of liquid/liquid interfacial tension measurement, a second immiscible liquid such as oil is introduced into a main channel, while the sample liquid is injected through the T-junction. The formation frequency of the microbubbles or microdroplets is a function of the interfacial tension between the two phases. This frequency can be measured easily by optical detection. Measurements were carried out for aqueous solutions with different concentrations of the ionic surfactant cetyl trimethyl ammonium bromide (CTAB). The actual interfacial tensions of these solutions were calibrated with a commercial tensiometer (FTA200, First Ten Angstrom). The measurement results show a clear relation between the interfacial tension and the formation frequency. Furthermore, our sensor can be used to identify the critical micelle concentration (CMC) of a surfactant. The sensor potentially allows the use of a minute amount of sample compared to the relatively large amount required for existing commercial systems 相似文献