Robust Flash Calculation Algorithm for Microemulsion Phase Behavior

The HLD-NAC model was recently modified to match and predict microemulsion phase behavior experimental data for Winsor type III regions. Until now, the HLD-NAC model could not generate realistic phase behavior for type II? and type II+ two-phase regions, leading to significant saturation and composition discontinuities when catastrophe theory is applied. These discontinuities lead to significant failures in modeling surfactant applications. We modify the HLD-NAC equations to ensure consistency over the entire composition space including type II? and II+ regions. A robust and efficient algorithm is developed that always converges and provides continuous estimates with any formation variable of tie lines and triangles for all Winsor types. Discontinuities are eliminated and limiting tie lines near critical points are determined analytically. The tuning procedure is demonstrated using several sets of experimental data. Excellent predictability of tie lines and tie triangles, and solubilization ratios are shown.     

微乳液在无机材料制备中的应用

对微乳液的结构特征及制备作了概括性的介绍。微乳液作为反应介质主要由于表面活性剂的分散乳化作用,综述了微乳液在无机材料制备中的应用。     

微乳液的结构及应用进展

系统阐述了微乳液的微观结构、相态、制备方法，并就微乳液在3次采油、纳米材料制备、有机化学反应、聚合反应、催化、分离过程等领域中的应用现状进行了详细探讨，并对微乳液的应用进行了展望。     

W/O型环己烷微乳液的研究

考察了不同种类醇、表面活性剂用量和配比对环己烷微乳液增溶水量和电导率的影响;探讨了电解质对环己烷微乳液相行为的影响。实验结果表明：正戊醇为最佳助剂,助剂与表面活性剂碳链比适中更易形成微乳液;随着表面活性剂质量分数的增加,体系增溶水量增大,电导率下降;电解质对环己烷微乳液有重要的影响,随着NaCl质量分数的逐渐增大,体系从下相微乳液过渡到中相微乳液,进而形成上相微乳液。     

Effects of Oleic Acid and Phospholipids on the Formation of Lecithin Organogel and Microemulsion

The formation of organogels and microemulsions of lecithin in the presence of a biocompatible cosurfactant, oleic acid, was studied. Low content of oleic acid ([oleic acid]/[lecithin] < 0.1) in the lecithin–oleic acid–dodecane–water system leads to an expansion of the region of existence and to a decrease in the viscosity of lecithin organogels. At high contents of oleic acid ([oleic acid]/[lecithin] > 0.6), low‐viscosity microemulsion exists in the system. Phosphatidylethanolamine, lysophosphatidylcholine, and other phospholipids that are present as impurities in the commercial samples of soybean lecithin can act as cosurfactants. For the first time, the formation of lecithin organogels in the systems containing commercial samples of soybean lecithin with phosphatidylcholine concentrations of 69.3 wt% (Lipoid S75) and 52.9 wt% (Lipoid S45) and saturated aliphatic hydrocarbons is demonstrated. The gelation is observed at T =25 °C in octane, decane, dodecane, and hexadecane for Lipoid S75 and in dodecane and hexadecane for Lipoid S45. A decrease in the degree of purification of lecithin leads to an expansion of the regions of existence of the organogels and to a reduction of their viscosity.     

Formation and Phase Behavior of Winsor Type III <Emphasis Type="Italic">Jatropha curcas</Emphasis>-Based Microemulsion Systems

The formation and phase behavior of Jatropha curcas-based microemulsion systems, which could potentially be used in enhanced oil recovery applications, has been investigated. Winsor type III microemulsions were obtained by adding n-octane to Winsor type I microemulsion systems prepared using various concentrations of alkyl polyglucoside (APG). To optimize the formulation of type III microemulsion systems, five different types of co-surfactants, i.e. normal butyl alcohol (NBA), isobutyl alcohol, isopropyl alcohol, fatty acid alcohol C8 (FAC8) and fatty acid alcohol C8/C10 (FAC8/C10) were used. The microemulsion phase behavior was determined along with particle size distributions by dynamic light scattering measurements. Results show that the optimum Winston type III system can be achieved by mixing 3 wt% of NBA, 1 wt% APG and 3 wt% NaCl. At the optimum formulation, the IFT reached a minimum value (0.016 mN/m) and formed very small emulsion droplets with a narrow particle size distribution.     

Solubilization Behavior of Organic Mixtures in Optimum Winsor Type III Microemulsion Systems of Sodium Dodecyl Sulfate

Solubilization selectivity and synergism behavior were investigated for the optimum Winsor type III sodium dodecyl sulfate (SDS) microemulsion systems of organic mixtures. The organic mixtures used include toluene and 1 of the following 3 normal alkanes: n‐octane, n‐heptane, and n‐hexane. Selective solubilization toward toluene was observed in the optimum Winsor type III SDS microemulsion system for the toluene/n‐octane mixture. Toluene selectivity showed a decrease trend with the increase of its content in the excess oil phase, salinity showed little influence on the trend, and increasing of the SDS content leads to lowering of the selectivity. Synergism exists in the solubilization of the 2 organics for all the binary mixtures used in this work. A clear reduction of the n‐butanol content (A*) to obtain the optimum formulation and rise of the optimum solubilization parameter (SP*) were seen with the mixing of 2 single components. Coincident relation between A* and equivalent alkane carbon number (EACN) for organic mixtures of toluene with the 1 or 3 of n‐hexane, n‐hexane, and n‐octane was obtained, which is a parabolic curve with a minimum point. At the same time, all the SP*–EACN data fall in the same kind of parabolic curve with a maximum. The EACN for the minimum A* and maximum SP* are both in the range of 3.0–3.5. The A*–EACN curve shifts vertically with the change of the SDS content or ln S* (S* is salinity of the aqueous phase), while the change of salinity also leads to slight deformation of the curve, which can be omitted in a small range of salinity change.     

Nanostructured Non-Ionic Surfactant Carrier-Based Gel for Topical Delivery of Desoximetasone

Psoriasis is a chronic autoimmune skin disease impacting the population globally. Pharmaceutical products developed to combat this condition commonly used in clinical settings are IV bolus or oral drug delivery routes. There are some major challenges for effectively developing new dosage forms for topical use: API physicochemical nature, the severity of the disease state, and low bioavailability present challenges for pharmaceutical product developers. For non-severe cases of psoriasis, topical drug delivery systems may be preferred or used in conjunction with oral or parenteral therapy to address local symptoms. Elastic vesicular systems, termed “niosomes”, are promising drug delivery vehicles developed to achieve improved drug delivery into biological membranes. This study aimed to effectively incorporate a corticosteroid into the niosomes for improving the drug bioavailability of desoximetasone, used to treat skin conditions via topical delivery. Niosomes characterization measurements were drug content, pH, spreadability, specific gravity, content uniformity, rheology, and physicochemical properties. Formulations used a topical gelling agent, Carbomer 980 to test for in vitro skin permeation testing (IVPT) and accelerated stability studies. The developed niosomal test gel provided approximately 93.03 ± 0.23% to 101.84 ± 0.11% drug content with yield stresses ranging from 16.12 to 225.54 Pa. The permeated amount of desoximetasone from the niosomal gel after 24 h was 9.75 ± 0.44 µg/cm² compared to 24.22 ± 4.29 µg/cm² released from the reference gel tested. Furthermore, a drug retention study compared the test gel to a reference gel, demonstrating that the skin retained 30.88 ng/mg of desoximetasone while the reference product retained 26.01 ng/mg. A controlled drug release profile was obtained with a niosomal formulation containing desoximetasone for use in a topical gel formulation showing promise for potential use to treat skin diseases like psoriasis.     

重烷基苯磺酸盐微乳体系的相行为

能使大庆原油／地层水界面张力降至超低５的重烷基苯磺酸盐（中试产品）在无醇、１０ｇＮａＣｌ／Ｌ条件下,地壬烷产生最低界面张力。在４５℃下,以行烷为油相,重烷基苯磺酸盐为表面活性剂,仲丁醇为助表面活性剂,可以与盐水形成微乳体系。对重烷基苯磺酸盐浓度０．１５ｍｏｌ／Ｌ（水相浓度）,仲丁醇／重烷基苯磺酸盐ｍｏｌ比＝１８．５：１,水／油体系比＝１：１的微乳体系,增加盐度可导致ＷｉｎｓｏｒＩ→ＷｉｎｓｏｒⅡ宫     

添加剂对烷基糖苷微乳液相图的影响

通过实验绘制了烷基糖苷(APG)微乳液的拟三元相图,发现少量的离子型表面活性剂能够使APG形成的单相微乳液区域变大。氯霉素、硼酸 /硼酸钠的缓冲溶液、NaCl以及洁而灭对微乳液区域影响非常小;透明质酸钠使微乳液相图区域减小,双连续的微乳液区域消失,这可能是因为透明质酸钠在油水中分配得不均匀,油包水型向双连续型微乳液过渡时,水含量增加,同时透明质酸钠的含量增加,油核里很难包结这种大分子,因此,微乳液被破坏。硼酸 /硼酸钠缓冲溶液的加入有助于提高氯霉素的稳定性。     

Microemulsion of erythromycine for transdermal drug delivery

The aim of this work was to prepare an erythromycin (EM) microemulsion (EM‐ microemulsion) for transdermal EM delivery using isotropic mixtures of oil and aqueous phases. The prepared EM‐microemulsion is a white dispersion, with a suitable viscosity for transdermal delivery. In stability experiments, the EM‐microemulsion showed no marked change in appearance for up to 3 weeks at 25°C. In accelerated stability experiments at 37 and 60°C, however, precipitated crystalline EM particles were observed in the EM‐microemulsion. Diffusion of EM into the skin exhibited a first order release profile. Fluorescein (FL)‐microemulsion penetrated to the dermis layer of skin. In conclusion, we confirmed that EM‐microemulsion could serve as an excellent transdermal carrier of EM. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Phase Behavior of Sodium Dodecyl Sulfate-n-Butanol-Kerosene-Water Microemulsion System

Experiments were carried out to investigate the influences of cation from electrolytes and acidity/alkalinity on the phase behavior of sodium dodecyl sulfate-n-butanol-organics-water （with electrolytes） microemulsion sys-tem. The organics used is commercial kerosene. The volume ratio of water to organics is 1︰1. The results show that the type and valence of electrolyte cations are important factors influencing the microemulsion behavior. Biva-lent Ca2＋is more effective than monovalent K＋and Na＋for the formation of Winsor type III and II microemulsion. For electrolytes with the same monovalent cation Na＋, i.e. NaCl and Na2CO3, anions in the electrolyte have some effect. Bivalent anion 23CO - leads to a lower activity of cation Na＋than monovalent anion Cl-. NaOH （or KOH） behaves similar with NaCl （or KCl）. When HCl is used as electrolyte, its acidity plays an important role. Phase in-version of microemulsion from type III （or II） to type I is observed through precipitation of Ca2＋using Na2CO3, neutralization of HCl by NaOH, and addition of water to the system, which releases the oil from the microemulsion.     

Phase behavior of the perfluoropolyether microemulsion in supercritical CO2 and their use for the solubilization of ionic dyes

Phase behavior of the perfluoropolyether surfactant microemulsion in supercritical CO₂ and the solubilization of conventional ionic dyes in the same system have been investigated using Perfluoro 2,5,8,11-tetramethyl-3,6,9,12-tetraoxapentadecanoic acid ammonium salt. We found that the surfactant prepared in this study was satisfactorily dissolved in supercritical CO₂ without the presence of entrainer. Moreover dissolved surfactant had an ability to form micellar aggregates and to incorporate a small amount of water in the interior of aggregates. We also found that conventional ionic dyes such as acid dye, reactive dye and basic dye were solubilized in the microemulsion system in supercritical CO₂.     

农药微乳液相行为及微乳结构的研究

首先绘制了LAS/TX—10/正丁醇/仲丁威/水体系的拟三元相图,讨论了m(LAS)/m(LAS+TX—10)及m(正丁醇)/m(LAS+TX—10)对相区的影响。发现m(LAS)/m(LAS+TX—10)越高,液晶区越大;比例越低,乳液区越大。m(正丁醇)/m(LAS+TX—10)越低,液晶区越大;比例越高,液晶区越小。通过电导率的测定研究了微乳结构及结构转变。当m(正丁醇)/m(LAS+TX—10)=1,m(LAS)/m(TX—10)=1/9或6/4时,微乳液转变经历了由W/O到双连续最后到O/W型;m(LAS)/m(TX—10)=9时,微乳液转变经历了由W/O到双连续、液晶最后到O/W型。     

双生表面活性剂微乳液的制备及其相行为研究

制备了双生表面活性剂α-磺基硬脂酸聚乙二醇双酯钠盐/醇/正辛烷/水微乳液体系,绘制了其拟三元相图,探讨了不同碳链长度的醇及0.1mol/LKCl、NaOH、HCl溶液对微乳区域的影响,利用电导率分析了微乳液的结构类型。结果表明:以α-磺基硬脂酸聚乙二醇双酯钠盐作为乳化剂,可以制备稳定的微乳液。在中等链长范围内,作为助表面活性剂的醇类,链长的比链短的醇具有更好的助活作用。电解质溶液一般使微乳区域缩小,以电解质溶液或纯水为分散介质的微乳液的电导率变化趋势基本相同。     

微乳液相行为的研究进展

对常用的微乳液相图——Winsor相图、δ-γ（T-γ）“鱼状”相图和ε-β“鱼状”相图的绘制方法、特点以及微乳液相关参数的计算等进行了介绍。Winsor相图直观简单,但提供的信息较少;δ-γ（T-γ）“鱼状”相图能得到微乳液组成的参数;ε-β“鱼状”相图则既能直观地观察到相态的变化,又能得到平衡界面膜的组成等性质。比较了三种相图的优缺点。     

微乳液法制备纳米材料的研究进展

微乳液法制备纳米材料可以控制纳米粒子的大小和形状。本文综述了影响纳米粒子的主要因素和微乳液法制备纳米材料的最新研究进展。     

助表面活性剂对乙草胺微乳液相图的影响

用拟三元相图法研究了醇醚糖苷(AEG)/醇醚羧酸盐(AEC)/醇/乙草胺/水体系的微乳液相行为,讨论了不同碳链长度的醇对乙草胺微乳液拟三元相图的影响,并通过电导率测定,研究了乙草胺微乳液的微观结构转变。结果表明,随着助表面活性剂醇碳链的增长,乙草胺微乳液的微乳区面积逐渐变小,而液晶区从无到有并逐渐增大;以正丁醇为助表面活性剂时,正丁醇的质量分数〔m(正丁醇)/m(AEG+AEC+正丁醇)〕对微乳区面积有一个最佳值。     

醇对乙草胺微乳液相图的影响

用拟三元相图法研究了醇醚糖苷（AEG）/醇醚羧酸盐（AEC）/醇/乙草胺/水体系的微乳液相行为,讨论了不同链长的醇对乙草胺微乳液拟三元相图相图的影响,并通过电导率测定研究了乙草胺微乳液的微观结构转变。结果表明：随着助表面活性剂醇碳链的增长,乙草胺微乳液的微乳区面积逐渐变小,而液晶区从无到有并逐渐增大;固定醇的种类为正丁醇时,醇的含量对微乳区面积有一个最佳值。     

微乳液相行为的研究进展

对常用的微乳液相图——winsor相图，δ-γ（T-γ）“鱼状”相图和ε-β“鱼状”相图——的绘制方法、相图特点以及微乳液相关参数的计算等进行了简要介绍。Winsor相图直观简单，但是提供的信息较少；δ-γ（T-γ）“鱼状”相图能得到微乳液组成的参数；ε-β“鱼状”相图则既能直观地观察到相态的变化，文能得到平衡界面膜的组成等性质。本文比较了三种相图的优缺点，为理论研究和实际应用提供指导。