Formulating Middle Phase Microemulsions Using Extended Anionic Surfactant Combined with Cationic Hydrotrope

The phase behavior of systems containing sodium alkyl polypropylene oxide sulfate with equimolar ratio of polypropylene oxide ammonium chloride was determined as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension (IFT) between the microemulsion and oil or brine. The fish diagram is presented showing a minimum amount of 0.20 wt% surfactant needed to form the middle phase. Swelling increases with decreasing the alkane carbon number of the oil. Ultra low IFT values were predicted for the systems investigated.     

Microemulsion Phase Behavior of Aerosol-OT Combined with a Cationic Hydrotrope in the Dilute Region

The phase behavior of systems containing minimum amounts of sodium bis (2-ethylhexyl) sulfosuccinate with equimolar ratio of tetra ethyl ammonium chloride were studied as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension. Ultra-low interfacial tension values were predicted for the systems containing heptane, octane and nonane as model oil. Different phase behavior was observed for systems with higher alkane number.     

Water-Diesel Microemulsions Stabilized by an Anionic Extended Surfactant and a Cationic Hydrotrope

Alcohol-free microemulsions were formulated using mixtures of extended surfactant (C_12-14-PO₁₄-EO₂SO₄Na), sodium dodecyl benzene sulfonic acid and cationic hydrotropes with equal amounts of water and diesel. The cationic hydrotropes had short hydrocarbon or propylene oxide chain. The formulation included sodium carbonate to convert naphthenic acids in diesel to soaps. The phase behavior at ambient temperature of oil-free mixtures as a function of NaCl concentration was investigated. Visual inspection as well as cross polarizers were used to detect anisotropy. The microemulsion fish phase diagram and solubilization ratios for diesel and brine in the middle phases were determined. The minimum surfactant concentration needed to initiate middle phase formation was 0.10 wt%.

Salinity scans revealed that optimal salinity can be adjusted according to the hydrophilic/lipophilic nature of the hydrotrope used. Interfacial tension measurements using a spinning drop tensiometer showed a minimum value of 0.0015 mN/m between middle phase microemulsion and excess brine and a value of 0.032 mN/m between diesel and brine.     

Studies on Phase Behavior of Alkyl Polyglucoside Based on Microemulsions with Modified Fishlike Phase Diagram

The three-phase behavior in the quaternary system of an alkyl (C8/10^- or C12/14^-)polyglucoside / 1-butanol / n-octane / water has been studied at 40℃ with the modified fishlike phase diagram, which is presented by us for the first time. The mass fraction of 1-butanol in the hydrophile-lipophile balanced interfacial layer, A^S, the coordinates of the start point B and the end point E of the phase diagram, and the solubilities of alkyl polyglucoside and 1-butanol in n-octane phase were calculated. The solubilization of the microemulsion was also discussed.     

助表面活性剂对阴/阳离子表面活性剂复配形成微乳液的影响

中相微乳液;盐度扫描;助表面活性剂对阴/阳离子表面活性剂复配形成微乳液的影响     

辛基三甲基溴化铵与辛基硫酸钠混合水溶液的相行为

对辛基三甲基溴化铵(OTAB)与辛基硫酸钠(SOS)正、负离子混合表面活性剂水溶液的相行为进行了研究.在高浓度的溶液中,混合表面活性剂形成液晶相,随着混合摩尔比OTAB/SOS接近于1,液晶结构由六角相转层状相,同时夹杂少量沉淀物;在中等浓度时,任意混合摩尔比例下皆为均相透明溶液;在低浓度下,在很宽的OTAB/SOS混合摩尔比的范围,出现双水相,其中的表面活性剂稀薄相,为不同大小的胶团与囊泡组成的稀溶液,另一表面活性剂富集相中则为数密度很大的囊泡聚集体,富集相对油溶性染料的增溶作用比非富集相高得多.     

混合碳链烷基聚葡糖苷中相微乳液的研究

用Winsor型相图、δ—γ“鱼状”相图和改进的ε—β“鱼状”相图研究了混合碳链烷基聚葡糖苷(APG：C8／10G1.31和C12／14G1．43)中相微乳液的相行为,结果表明,随醇浓度的增加,微乳液类型发生Winsor Ⅰ→Ⅲ→Ⅱ的转变,从Winsor型相图直接观察到醇浓度增加时,微乳液三种类型的变化、各相体积以及中相微乳液形成和消失时醇的浓度,从“鱼状”相图除得到中相微乳液形成和消失时的组成,以及单相微乳液形成时的组成外,还可得到平衡界面膜的组成、表面活性剂单体分子和醇在油相中的溶解度及表面活性剂形成单相微乳液的效能等,在比较上述两种相图优缺点的基础上,我们首次提出了改进的“鱼状”相图,把两者的优点集中于该图中,既能直观地观察出体系相态的变化,又能得到平衡界面膜的组成等其它性质,为理论和实际应用提供更多信息和方便。     

烷基芳基磺酸盐结构对微乳液相行为的影响

用Winsor相图法研究了自制的6种不同结构的烷基芳基磺酸盐/不同醇/正癸烷/NaCl/水体系在不同温度下所形成的微乳液。 探讨了烷基芳基磺酸盐结构对微乳液相行为的影响。 同时考察了温度和醇对微乳液相行为的影响。 结果表明,随着烷基芳基磺酸盐长烷基链的增长,中相形成盐度S1、中相消失盐度S2、中相盐宽ΔS和最佳盐浓度S*值均减小,最佳中相体积V*M和最佳增容量σ*值均增大;随着烷基芳基磺酸盐分子的芳环向长烷基链中间位置移动,S1、S2、ΔS、S*值均减小,V*M和σ*值均增大;随着温度升高,V*M和σ*值均减小,S1、S2、ΔS、S*值均增大,在25 ℃时,体系无中相微乳液形成;随着正构醇碳原子数的增加,V*M和σ*值均增大,S1、S2、ΔS、S*值均减小。     

Phase Behavior of Bicontinuous and Water/Diesel Fuel Microemulsions Using Nonionic Surfactants Combined with Hydrophilic Alcohol Ethoxylates

Bicontinuous and water-in-diesel microemulsions were formulated using single nonionic alkyl poly glycol ethers combined with hydrophilic alcohol ethoxylates. The phase behavior at temperatures ranging from 0°C to 50°C was investigated. Visual inspection as well as cross-polarizers were used to detect anisotropy. The fish phase diagrams were determined. The presence of the hydrophilic alcohol ethoxylates was necessary to initiate both types of microemulsions. Increasing the hydrophobic chain length of the surfactant led to a wider range of temperature stability at lower surfactant concentration. Meanwhile, increasing the ethylene oxide units in the headgroup by two units led to a phase diagram that is dominated by lyotropic liquid crystal. The formulated water in diesel microemulsions were tested experimentally in a 4-cylinder diesel engine. From this it is observed that the emissions of NO_x, soot, and CO₂ were reduced substantially compared to neat diesel, while for the CO the reduction occurs just at low load.      

Mixing Behavior of Cationic Hydrotropes with Anionic Surfactant Sodium Dodecyl Sulfate

Mixing behavior of anionic surfactant sodium dodecyl sulfate (SDS) with cationic hydrotropes aniline hydrochloride (AH), o-toluidine hydrochloride (o-TH), and p-toluidine hydrochloride (p-TH) have been studied using conductivity at different temperatures. Critical micelle concentration for different mixing mole fractions, their ideal values, and different interaction parameters have been estimated. All the parameters show nonideal behavior with synergistic interactions. Thermodynamic parameters are also calculated for these systems.     

辛烷基酚聚氧乙烯醚反相微乳体系的相行为及纳米复合碳酸盐的制备

绘制了一系列辛烷基酚聚氧乙烯醚(OP-10)+正辛醇+环己烷+水(或CaCl₂水溶液)拟三元体系相图,分别研究了助表面活性剂正辛醇的添加比例和CaCl₂水溶液的浓度对微乳区域的影响,发现在OP-10+正辛醇+环己烷+水拟三元体系相图中,随着正辛醇/OP-10的质量比逐渐增大,微乳区的面积逐渐增大,当正辛醇/OP-10质量比为1:2.5时微乳区的面积最大,之后微乳区面积随着其质量比的增大而减小,表明适量地加入助表面活性剂正辛醇有利于微乳区的形成;但过多地增加正辛醇的量反而不利于微乳相的形成。 确定正辛醇/OP-10的质量比为1:2.5,改变CaCl₂的浓度,发现OP-10+正辛醇+环己烷+CaCl₂水溶液拟三元体系相图中,CaCl₂浓度为0.1 mol/L时微乳区面积最大。分别配制总浓度为0.1 mol/L的5种不同摩尔比的Ca²⁺/Ba²⁺微乳液,并与等摩尔的碳酸钠水溶液反应制备共沉淀碳酸盐,使用扫描电子显微镜(SEM)对所制备样品进行表征分析,发现当微乳液为钙离子盐时,主要形成大的立方形颗粒;掺入钡离子,Ca²⁺和Ba²⁺摩尔比为3:1、1:1和1:3时,形成的沉淀分别为四棱锥形、球形和玉米棒形;当微乳液为钡离子盐时,沉淀主要为不规则多面体。     

Study and Modeling of Metal Oxide Solubilization in (w/o) Microemulsions

Water-in-oil (w/o) microemulsions are very appealing reaction media due to their ability to provide huge surface of contact between water-soluble and oil-soluble reactants. Their application as reaction media, including the preparation of nanoparticles, is, however, limited to water soluble precursors. In this study, we present a first step scheme in a two-step process for the preparation of metal oxide nanoparticles starting from their water-insoluble metal oxide bulk powder. This step involves solubilizing the metal oxide in the water pools of the microemulsion with the aid of a solubilizing agent. The variables affecting the solubilizing capacity of iron and copper oxides, as examples of important metal oxides, in single HCl-containing AOT/water/isooctane microemulsions were investigated. The effect of the following variables on the solubilization capacity is reported, namely, mixing time, surfactant concentration, water to surfactant mole ratio (R), and the nominal concentration of HCl in the water pool. At 300-rpm, time-invariant concentration of the metals in the microemulsions was achieved in about 6 hours. These values were quoted as the solubilization capacity of the metal oxide at the corresponding conditions. Solubilization capacity increased linearly with the surfactant concentration and R, and portrait a power function with the nominal concentration of HCl in the water pool. A mathematical model previously derived to describe nanoparticle uptake by single microemulsion accurately accounted for the effect of the aforementioned variables on the solubilization capacity.     

碱和盐对十二烷基硫酸钠/正戊醇-环己烷-水拟三元体系相图影响

拟三元相图的研究可为获得制备纳米材料的微乳液提供理论依据。本文首先通过实验绘制了45℃下十二烷基硫酸钠(SDS)/正戊醇-环己烷-水溶液体系的拟三元相图,并用电导法进行了验证,说明电导的测定结果与相图吻合的很好。其次,绘制了45℃及65℃下,SDS/正戊醇-环己烷-水、SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图并对6个相图进行了比较,研究了碱(NaOH)和盐(Zn(NO_3)_2)对SDS/正戊醇-环己烷-水拟三元体系相图影响。结果表明,硝酸锌及碱的加入使SDS/正戊醇-环己烷-水拟三元相图水包油(O/W)和油包水(W/O)区域明显的缩小。45℃时,SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中的O/W区域甚至消失;65℃时,O/W和W/O区域均存在,且3个相图的W/O和O/W区域有重叠区。在此基础上,确定了制备纳米Zn O的微乳液的条件,即SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中W/O区域的重叠区(各相图中的Ⅱ区)。制备的纳米氧化锌为多晶结构,平均粒径为80 nm。     

Phase behavior of pseudoternary brine/alkane/alcohol-secondary alkanesulfonates systems

Dodecanesulfonates (isomer mixtures) have been synthesized by the process developed in our laboratory. First, pseudoternary phase diagrams of water or (brine) decane/dodecanesulfonates-butan-1-ol systems were drawn and compared with those of a commercial sample (Hostapur 60). In the presence of NaCl, a three-phase region (Winsor III) appears for the two systems, and is larger with the home-made surfactants. This region is interesting in enhanced oil recovery because it leads to very low interfacial tensions. Then, the behavior of the Winsor III region was investigated as a function of the alcohol/surfactant mass ratio (C/T). At a constant salinity (2.5 mass% NaCl) a value of 2 for C/T gives the best compromise for a larger WIII region with both systems. For this ratio, optimal salinity values of 1.55 and 1.65 mass% for our sample and Hostapur 60, were found, respectively.     

阳离子表面活性剂中相微乳的形成和特性

自1943年SdriAn。等人山发现微乳液体系并予以命名以来，对微乳液研究不断深入·微乳液是由油、水、表面活性剂和助表面活性剂组成的各向同性、透明的、热力学稳定的分散体系，微乳液可分为单相微乳液和多相微乳液问．中相微乳液是多相微乳液中，与过剩盐水相和过剩油相达到三相平衡的Winsor皿型微乳液，它在三次采油、日用化工、微环境、酶催化等方面具有特殊重要的应用I‘，‘］．近年来对阴离子表面活性剂中相微乳液的形成和特性进行了较多研究［5。8］．但对阳离子表面活性剂中相微乳液的研究，目前尚未见报导，本文以澳代十四烷基毗…     

二烷基磷（膦）酸钠盐萃取体系的相行为

用二烷基磷（膦）酸钠盐ＮａＡ作为阴离子表面活性剂，测定了ＮａＡ－醇－油－水体系Ｗ／Ｏ型微乳液中水的增溶量，用类三元相 图单相微乳区，测定了ＮａＤＴＭＰＰ－ＨＤＴＭＰＰ－煤油－水（含Ｎａ２ＳＯ４）体系相的变化，并讨论了溶剂、醇、温度、含盐量等对相行为的影响。     

氰戊菊酯微乳液相行为及其结构转变

氰戊菊酯微乳液相行为及其结构转变;相行为; 微乳液; 电导率; 氰戊菊酯     

Phase Behavior and Dielectric Spectroscopy of the Sodium Dodecyl Trioxyethylene Sulfate／n－Butanol／Water System

Introduction　　Itiswellknownthatsurfactantsinanaqueoussolu tioncouldformmicellesataconcentrationhigherthanthecriticalmicelleconcentration (cmc) .Knowledgeofalcoholsolubilizationinaqueousmicellesolutionsisimportantinunderstandingtheaggregationbehaviorofsuchsystemsandisrelevanttoseveralindustrialprocesses .1Manystudieshavebeenreportedonphasebehaviorofternarysystemsofionicsurfactant,alcohol,andwater.2 7Generally ,inthecaseofshortchainalcohol,atransparent,isotropic ,andlow viscosityphaseappearse…     

新型农药丙酯草醚对微乳液体系相行为的影响

表面活性剂;微乳液;“鱼形”相图;丙酯草醚     

烷基聚葡糖苷C9.6G1.3/n-C4H9OH/n-C6H14/H2O微乳液体系的介电弛豫谱研究

The pseudotertiary phase diagram of the microemulsion system alkyl polyglucoside/n-butanol/n-hexane/water was plotted at （30.0±0.1） ℃. The dielectric measurements, including permittivity, conductivity, relaxation strength, characteristic relaxation time, etc,, were applied to investigate the microstructure of the system. Unique dielectric relaxations were observed over the frequency range of 5-10^7 Hz, taking place possibly through an interracial polarization mechanism. According to the results obtained from dielectric spectroscopy, the structures of the microemulsion O/W, BC and W/O were determined, and some dielectric and phase parameters were calculated.