油水乳状液膜稳定性实验研究

液膜分离技术以液膜为分离介质、以浓度差为推动力,具有快速、高效、专一和节能等优点。在液膜分离过程中,液膜稳定性是一个主要的难题。本文以酚酞作为指示剂,用邻苯二甲酸氢钾标准溶液滴定法测定外相中的NaOH浓度,从而分析评价乳状液膜的稳定性。考察了实验时间、内相NaOH浓度、表面活性剂Span80的用量、膜相添加剂液体石蜡对乳状液膜稳定性的影响。研究结果表明,随着实验时间的延长,乳状液膜的稳定性下降;当内相NaOH浓度的增大时,液膜破损率提高,即液膜稳定性降低;当Span80用量为5%时,液膜破损率最小,液膜稳定性最好;液体石蜡用量为3%～9%时,随着液体石蜡的加入,液膜的破损率增大,当膜相添加剂液体石蜡的用量控制在3%以下时,液膜稳定性较强。     

固体颗粒对油水界面性质及乳状液稳定性的影响

采用界面张力仪、表面粘弹性仪和Zeta电位仪,研究了固体颗粒对胜利原油油水界面性质及乳状液稳定性的影响。结果表明,固体颗粒的存在使得油水界面张力及界面剪切粘度增加,O/W型乳状液的稳定性增加,而且随固体颗粒浓度增加,乳状液稳定性增强;在0.21~500μm范围内,固体颗粒粒径减小,其与原油形成的O/W乳状液稳定性增强,乳状液内部油珠表面Zeta电位负值增加。     

影响农药水乳剂稳定性因素与控制（上）

目前国内研发并投放市场的水乳剂产品与国外产品相比有较大差距,主要为国内产品在常温贮存过程中,易分层、沉降和析出晶体,从而降低药效。论述了有关影响水乳剂稳定性因素（包括分层或沉降、絮凝、聚结或破乳、奥氏熟化和转相）。详细讨论了从乳化剂的选用、乳化剂的用量、液滴尺寸及分布、温度和黏度来控制水乳剂稳定性。指出水乳剂的热贮和冷贮与常温长期贮放稳定性间并无内在联系。水乳剂的经时稳定性是二年货架寿命重要保证。可用粒度分布仪和全能稳定性分析仪来预测水乳剂的稳定性。     

影响农药水乳剂稳定性因素与控制（下）

目前国内研发并投放市场的水乳剂产品与国外产品相比有较大差距,主要表现在国内产品在常温贮存过程中,易产生分层、沉降和析出晶体的情况,从而药效降低。论述有关影响水乳剂稳定性因素（包括分层或沉降、絮凝、聚结或破乳、奥氏熟化和转相）。详细讨论了从乳化剂的选用、乳化剂的用量、液滴大小及分布、温度和黏度来控制水乳剂稳定性。指出水乳剂一般在热贮和冷贮与常温长期贮放条件下其稳定性间并无内在联系。水乳剂的经时稳定性是二年货架寿命重要保证。粒度分布仪和全能稳定性分析仪可用来预测水乳剂稳定性。     

原油乳状液稳定性与乳化剂关系研究

分析了油水两相之间的界面张力大小,通过乳化实验测出乳状液的黏度变化和稳定时间,再借助显微镜观察水滴分散程度,最后得出对于酯类和磺酸盐类等大多数乳化剂,疏水基单烷基链越长,在油相中与油相之间交错的程度就会越复杂,配制出的乳状液性能越好;若乳化剂的疏水基团中存在不饱和双键,在空间上限制了烷基碳链在油相中的三维伸展,形成的乳状液乳化效果越差;若乳化剂的疏水基团中存在与烷基主链相同的支链,由于氢键的存在严重限制了疏水基在油相中的分散吸附,同时由于界面膜之间也会产生有一定的角度,使得界面膜的排列紧密程度变弱,导致乳状液性能变差。     

化工过程中的多尺度效应

以煤的清洁燃烧为例说明了多尺度效应是多数化工过程的内在特征，利用多尺度分析和能量最小化原理，建立了流化床反应器颗粒流体的分布数学模型，给出了模型求解过程，该模型可以解析求解，也可以数值求解。     

添加剂对柴油机润滑油油水界面性质及乳状液稳定性的影响

测定了柴油机油模拟油/蒸馏水体系的界面张力、界面剪切粘度和乳状液稳定性。结果表明,含有添加剂T154的柴油机油模拟油与蒸馏水间的界面张力明显低于无添加剂的体系的界面张力,界面剪切粘度增加,乳状液特性值比模拟油/蒸馏水体系稍大,乳状液稳定性增加;添加剂T109却使模拟油与蒸馏水体系的界面张力增大,界面剪切粘度降低,乳状液特性值比模拟油/蒸馏水体系小,乳状液稳定性降低,有一定的破乳作用。     

油包水乳状液微观特性进展研究

油包水乳状液的微观特性是影响乳状液稳定性的重要因素。为了降低采出液破乳难度、减小管线运输负担,有必要弄清楚乳状液的微观特性。影响油包水乳状液稳定性的微观因素主要有四部分:乳滴的大小、形状以及分布,乳状液界面张力,界面膜性质和界面剪切黏度。阐述了影响乳滴大小、形状、分布主要因素的研究进展,并简要介绍了乳状液液滴粒径分布的测量方法;报告了油包水乳状液界面张力大小主要影响因素的研究现状;阐述了界面膜的分子密度与机械强度对油包水乳状液稳定性的影响;对乳状液界面剪切黏度的影响因素进行了研究,对界面剪切黏度的研究现状作出评述,并介绍了测量界面剪切黏度的方法。     

树脂-水泥界面改性的多尺度表征

为从多尺度层次探明水泥基体与透明树脂界面以及偶联剂对界面的改性作用,利用硅烷偶联剂A-151和液体铝酸酯偶联剂处理水泥与树脂界面,采用抗拉和斜剪、显微硬度、FTIR和ESEM等测试手段从宏观、细观、微观尺度来表征界面的粘结强度、显微硬度、微观形貌和化学反应.结果表明:在宏观方面,硅烷偶联剂A-151和液体铝酸酯偶联剂能大幅提高树脂-水泥界面抗拉和斜剪强度,28 d强度至少提高73%和40%.在细观方面,偶联剂改善了透明树脂与水泥基体界面显微硬度,特别是在界面-10~10 μm区间内,且降低透明树脂"性能减弱区域"厚度达100 μm.在微观方面,硅烷偶联剂A-151、液体铝酸酯偶联剂与水化硅酸钙CSH中羟基OH反应分别生成Si-O-Si键和Al-O-Si键,偶联剂促使水泥净浆与透明树脂更好地融合,极大地改善了界面粘结情况.     

乳状液膜的稳定性讨论

本文就乳化液膜分离技术中最关键的问题即液膜的稳定性,综述回顾了新型液膜用表面活性剂使膜稳定的机理及其合成状况,讨论了表面活性剂、流动载体、添加剂等因素对乳状液膜稳定性的影响。并介绍了近年来人们在改进液膜稳定性方面所作的努力,展望了液膜工业化前景。     

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.     

胜利坨一聚合物驱采出液油水界面性质及乳状液稳定性研究

用界面张力仪、表面粘弹性仪和Zeta电位仪测定了胜利坨一原油模拟油与采出水间的界面特性,并研究了聚合物3530S浓度对这些界面特性及乳状液稳定性的影响。结果表明,由于采出水中含有固体悬浮物,使得过滤后采出水与原油模拟油间的界面张力和界面剪切粘度降低;模拟水中加入聚合物后,模拟水与原油模拟油间的界面张力和界面剪切粘度及油滴表面的Zeta电位绝对值均增大,原油与含聚合物溶液的模拟水间所形成的W/O乳状液稳定性随聚合物浓度增加先增强后减弱,存在一个使乳状液最稳定的聚合物浓度。     

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。     

聚合物3530S对坨一原油各组分油水界面性质及乳状液稳定性影响

用界面张力仪、表面粘弹性仪和Zeta电位仪研究了聚合物3530S对胜利坨一原油各组分模型油与模拟水间的界面特性及乳状液稳定性的影响规律。结果表明,沥青质及胶质模型油与模拟水间的界面张力低于蜡组分模型油,原油中的界面活性组分主要为沥青质和胶质。聚合物加入模拟水后,含有聚合物的模拟水与沥青质、胶质及蜡组分模型油之间的界面剪切粘度与界面张力均上升,油滴表面的Zeta电位降低。沥青质和胶质模型油与含聚合物3530S的模拟水所形成的W/O乳状液较蜡组分模型油所形成的W/O乳状液更稳定。     

Emulsifying properties and surface behavior of native and denatured whey soy proteins in comparison with other proteins. Creaming stability of oil-in-water emulsions

In this work a comparative study of emulsifying and surface behaviors of native whey soy proteins (NWSP) and denatured whey soy proteins (DWSP) with those of native soy isolates, denatured soy isolates (DSI), and sodium caseinate was done. These samples showed different molecular mass distributions in gel filtration profiles. Dissociation and soluble high-M.W. species in DWSP and DSI were observed. Lower interfacial and surface pressure values were obtained with native samples. Thermal treatment and salt addition enhanced tensioactivity in all fractions. Backscattering measurements of all oil-in-water emulsions, which exhibited a trimodal size distribution of droplets, showed the existence of a negative correlation with the median diameter of droplets. Greater droplet sizes were observed with NaCl addition. The NWSP emulsion had the lowest stability against creaming. Denaturation of this sample increased stability and favored air incorporation in emulsions. Destabilization depends not only on median droplet size but also on floc formation and structure. NaCl addition negatively affected the creaming stability only in emulsions formulated with soy isolates. The use of denaturation to enhance the surface and emulsifying properties of whey soy proteins would allow their use in food emulsions.     

胜利坨11南交联聚合物驱采出液油水界面性质及乳状液稳定性研究

用界面张力仪、表面粘弹性仪和Zeta电位仪测定了胜利坨11南原油模拟油与采出水间的界面特性,研究了聚合物、交联剂及弱凝胶对这些界面特性及乳状液稳定性的影响。结果表明,模拟水中加入聚合物、弱凝胶后,模拟水与原油模拟油间的界面张力、界面剪切粘度和油滴表面的Zeta电位绝对值增加,原油与含聚合物和弱凝胶的模拟水间所形成的W/O和O/W乳状液稳定性随聚合物、弱凝胶浓度增加而增强;交联剂对原油模拟油与模拟水间的界面性质及所形成的乳状液稳定性影响很小。     

Interfacial viscosity and the stability of emulsions

A viscous traction interfacial viscometer was constructed to study a mineral oil-water-emulsifier system. The effect on interfacial viscosity of the synthetic emulsifiers Span 80 and Pluronic L42 were investigated, along with the bioemulsifier produced by the yeast Torulopsis petrophilum. In the case of the synthetic emulsifiers, it was found that conditions which maximized interfacial viscosity also maximized emulsion stability. The same relation held for T. petrophilum emulsifier once all free fatty acids had been removed from the broth. Emulsion stability was measured by calculating mean diameters, as well as emulsion indices.     

Breakup of non-newtonian emulsion jets

The breakup of non-Newtonian emulsion jets into drops was experimentally studied by ejecting both O/W and W/O emulsions vertically downward into stagnant air through nozzles. Breakup lengths of non-Newtonian emulsion jets were found to be almost equivalent to those of Newtonian jets. Experimental breakup data establish that the static surface tension of the oil phase can be used as the surface tension of W/O emulsion jets, whereas the dynamic surface tension of aqueous surfactant solutions is used as that of O/W emulsion jets. Diameters of drops formed from non-Newtonian emulsion jets are in good agreement with the prediction from the stability theory previously developed by the authors. When the rheological index in a power law model is appreciably smaller than unity and the Ohnesorge number is significantly large, however, drop sizes are larger than the prediction because of the profile relaxation in jets. The critical velocity of emulsion jets, either O/W or W/O emulsion, is significantly lower than that of homogeneous Newtonian jets.     

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

The continuous phase of high internal phase emulsions (HIPEs) can be polymerized to produce highly porous materials, known as polyHIPEs. The aim of this work was to synthesize polyHIPE microfiltration membranes having a hydrophobic bulk and a hydrophilic surface to enhance their performance. Therefore, in situ functionalization was performed through interfacial copolymerization of a hydrophobic monomer (butyl acrylate) in the continuous phase with a hydrophilic monomer (sodium acrylate) in the disperse phase. The functionalization of polyHIPEs was studied by using conductometric titration and Fourier transform IR spectroscopy. We show that the surface charge density of poly(butyl acrylate)‐based polyHIPEs can be controlled by varying the concentration of sodium acrylate in the disperse phase. PolyHIPE microfiltration membranes have higher intrinsic permeability (around 1.31 × 10^?8 m²) in comparison to conventional microfiltration membranes. The interfacial copolymerization of sodium acrylate increases the permeability of microfiltration membranes. In addition, the rejection of polyHIPE microfiltration membranes was studied for the separation of microalgae. © 2019 Society of Chemical Industry