微乳液毛细管电动色谱烷基苯的保留行为

以阴离子表面活性剂十二烷基硫酸纳（SDS）和阳离子表面活性剂十六烷基三甲基溴化铵（CTMAB）组成的微乳液体系为分离介质,研究一组烷基苯同系物的毛细管电动色谱分离,较系统地考察了多种微乳液条件下溶质的保留时间,容量因子和电动色谱时间窗。结果表明,在SDS组成的微乳液体系中,烷基苯同系物的logk′与烷基链碳数(C=0～5)呈良好线性关系,logk′=aC+b,r＞0.9921。微乳液组成的变化对两种体系的电动分离有不同的影响规律,并对作用机理进行了探讨。     

微乳液毛细管电动色谱研究

本文研究了两组混合样的微乳液毛细管电动色谱(MEEKC)分离, 较系统地研究了微乳液的内相, 助表面活性剂及其浓度对电动分离的迁移时间、柱效及时间窗的影响, 并与胶束毛细管电动色谱(MEKC)分离进行了比较, 选用由80mmol/L正辛烷-120mmol/L十二烷基硫酸钠-900mmol/L正丁醇-10mmol/L硼砂组成的微乳液, 样品组分电动色谱迁移时间的RSD<0.8%, 峰面积RSD<3.0%.     

胶束电动色谱分离5种二氢吡啶类钙拮抗剂

应用胶束电动毛细管色谱,以４０ｍｍｏｌ／Ｌ硼砂－４０ｍｍｏｌ／Ｌ十二烷基硫酸钠（ＳＤＳ）为运行缓冲溶液,柱温６０℃,在１３ｍｉｎ内分离了５种二氢吡啶类钙拮抗剂药物。讨论了它ＳＤＳ浓度、硼砂浓度、缓冲溶液ＰＨ、柱温对迁移时间和分离的影响。     

用胶束电动毛细管色谱法分离黄芩中黄酮类有效成分

应用胶束电动毛细管色谱技术分离黄芩中主要的黄酮类有效成分并进行分析,确定它们分别是：黄芩甙、黄芩素、汉黄芩甙、汉黄芩素、木蝴蝶素Ａ及木蝴 Ａ－７－Ｄ－葡萄糖甙。缓冲液由２０ｍｍｏｌ／ＬＳＤＳ、２０ｍｍｏｌ／ＬＬ的磷酸三氮钠及２５ｍｍｏｌ／Ｌ的硼砂组成,溶液的Ｐ来７．２４。在胶束电动车管色谱分析中,黄芩中的主要黄酮类有铲成分在１５ｍｉｎ内即可达到基线分离,并且能对黄芩甙进行定量分析,笔者还讨论了表面     

蛋白质的微乳液毛细管电动色谱分离研究

考察了用微乳液毛细管电动色谱(MEEKC)分离蛋白质时微乳液组成等不同因素对分离的影响,并与胶束电动色谱进行对比,探讨了其分离机理,为蛋白质的分离鉴定提供了一种有力的工具.     

他汀类药物在微乳液相色谱体系中的保留行为

以普伐他汀钠、阿托伐他汀钙、辛伐他汀和洛伐他汀为研究对象,考察了微乳液流动相中表面活性剂的浓度、油相浓度、助表面活性剂浓度以及流动相的pH值等对他汀类药物在微乳液相色谱体系中保留行为的影响。实验结果表明,微乳流动相中表面活性剂、助表面活性剂、亲脂性溶剂的浓度对他汀类药物保留行为的影响与理论模型一致;流动相的pH值对酸性他汀类药物保留行为的影响与理论模型基本一致,对中性他汀类药物保留行为的影响存在着隐函数关系。所建立的保留模型能较好地反映微乳液组成对他汀类药物保留行为的影响。     

微乳毛细管电动色谱分析窗口的研究

研究了微乳毛细管电动色谱体系中,表面活性剂、助表面活性剂、微乳液的内相、有机改性剂等微乳组成对分析窗口的影响.以甲醇为电渗流标记物测定电渗流时间,以强疏水性化合物菲为标记物测定微乳液滴(假固定相)的迁移时间,分析时间窗口的变化.最佳条件下,菲的迁移时间和峰面积的相对标准偏差小于1.6%和3.0%(n=6),体系稳定,重复性良好.根据时间窗口的变化规律对其进行适当调节,成功实现了5种水溶性和2种脂溶性维生素的分离,并与毛细管区带电泳及胶束毛细管电动色谱进行了比较.     

微乳液毛细管电动色谱快速分析解热镇痛药中的有效成分

建立了微乳液毛细管电动色谱快速测定解热镇痛药中非那西丁、氨基比林和咖啡因的新方法。采用由乙酸乙酯-十二烷基硫酸钠(SDS)-正丁醇-硼砂缓冲液组成的微乳液体系,以氯霉素为内标,3种有效成分在2.5 min内完成分离,峰面积相对标准偏差(RSD)在1.2%～1.6%之间,回收率在95.6%～104.0%之间。实验考察了缓冲溶液的浓度、pH值、SDS浓度以及助表面活性剂的种类、含量对分离测定的影响。该法可用于实际样品分析。     

毛细管微乳液电动色谱的原理及应用

综述了近年来毛细管微乳液电动色谱(MEEKC)的研究进展。对MEEKC的分离原理进行了阐述;对微乳液的组成和其他影响MEEKC分离的因素进行了总结;对MEEKC在各个领域的应用作以分类评述;并将MEEKC和胶束电动毛细管色谱(MEKC)予以比较。     

酸性药物在微乳液相色谱体系中的保留行为

以酸性药物萘普生、布洛芬、双氯芬酸、苯丙氨酸和2,4-二氯苯氧基乙酸为研究对象,探讨了酸性药物在微乳液相色谱体系中保留机理,建立了酸性药物的容量因子(k′)与表面活性剂浓度、助表面活性剂浓度、亲脂性有机溶剂浓度以及流动相pH值之间的相关模型。结果表明,表面活性剂、助表面活性剂和亲脂性有机溶剂的浓度以及流动相pH值的变化对酸性药物的容量因子的影响完全与理论模型相吻合。所建立的保留模型能较好地反映在微乳液相色谱体系中微乳液组成和pH值对酸性药物保留行为的影响。     

Microemulsion elastomers

ABA-triblock copolymers bearing polymerizable methacrylate end-groups are covalently crosslinked in the droplet phase of W/O- and O/W-microemulsions. The resulting microemulsion elastomers combine the structure and the phase behavior of microemulsions with solid state properties such as elasticity or stability of shape. These new materials are characterized with the help of conductivity, dynamic-mechanical and dynamic light-scattering investigations. The influence of the chemical crosslinking process on the phase behavior and the dynamics of the underlying microemulsion is discussed.Dedicated to Prof. Dr. Hans-Friedrich Eicke on the occassion of his 65th birthday     

微乳液结构和丙烯酰胺反相微乳液聚合

本文对微乳液的结构及其特征作了概括性的论述，并着重总结了近年来在微乳液聚合方面的研究成果，特别是对丙烯酰胺，丙烯酸盐以及（２－甲基丙烯酰氧乙基）三甲基氯化铵等单位的反相微乳液聚合的研究工作进行了详尽论述。     

八甲基环四硅氧烷的微乳液聚合

八甲基环四硅氧烷的微乳液聚合;聚硅氧烷;微乳液聚合;成核机理     

微乳液聚合研究进展

从聚合机理和所得聚合物性能两个方面,分析总结了微乳液聚合与乳液聚合的差别.并介绍了微乳液聚合研究的国内外研究动态.     

微乳及其应用

微乳在生物技术、人造血管、酶固定化、能源科学、纳米材料、涂料、医药、食品、石油、选矿、环境等方面得到了越来越广泛的关注和应用。对微乳的理论研究、组成、制备方法、性质表征及应用的研究作了阐述。微乳技术具有很好的发展前景。     

Microemulsion polymerization of styrene

Initiation of polymerization in styrene oil-in-water microemulsions by water-soluble potassium persulfate of oil-soluble 2,2′-azobis-(2-methyl butyronitrile) at 70°C gave stable latexes which were bluish and less translucent than the original microemulsions. The effects of initiator concentration, polymerization temperature, and monomer concentration on the kinetics, particle size distributions, and molecular weight distributions were investigated. The kinetics of polymerization were measured by dilatometry. In all cases, the polymerization rate shows only two intervals, which increased to a maximum and then decreased. There was no apparent constant rate period and no gel effect. A longer nucleation period was found for polymerizations initiated by potassium persulfate as compared to 2,2′-azobis-(2-methyl butyronitrile). The small latex particle size (20–30 nm) and high polymer molecular weight (1–2 × 10⁶) implies that each latex particle consists of two or three polystyrene molecules. The maximum polymerization rate and number of particles varied with the 0.47 and 0.40 powers of potassium persulfate concentration, and the 0.39 and 0.38 powers of 2,2′-azobis-(2-methyl butyronitrile) concentration, respectively. This is consistent with the 0.4 power predicted by Smith–Ewart Case 2 kinetics. Microemulsion polymerizations of styrene–toluene mixtures at the same oil-water phase ratio gave lower polymerization rates and lower molecular weights, but the same latex particle size as with styrene alone. A mechanism is proposed, which comprised initiation and polymerization in the microemulsion droplets, by comparing the kinetics of microemulsion polymerization with conventional emulsion and miniemulsion polymerization systems.     

Pesticides as Microemulsion Formulations

Conventional systems like wettable powders, emulsifiable concentrates (ECs), oil in water emulsions (O/W emulsions), water in oil emulsions (W/O emulsions), aqueous suspension concentrates etc. are popularly used as the pesticide formulations. However, the microemulsion systems are preferred for their long-term thermodynamic stability, low viscosity, cost economy, and aesthetic appeal. Such systems provide a method for preparing an isotropic mixture of oil and water. Major advantage of microemulsion is in usage of the widely, easily available, environmentally friendly, and least expensive diluents, water. Formulation of pesticide microemulsion is a difficult task. The present investigation deals with the systematic study to arrive at the economical composition for microemulsion and solubilized systems. These compositions gave maximum stability with the optimum usage of surfactants. The microemulsion and solubilized systems when further diluted with water gave macroemulsion and microemulsion respectively, which were stable over an extended period of time.     

微乳毛细管电动色谱微乳粒径电化学测定方法研究

以二茂铁(Fc)作为电化学探针,采用循环伏安法测定了微乳毛细管电动色谱中常用水包油型微乳体系十二烷基硫酸钠(SDS)/正丁醇/正辛烷在不同配比下的扩散系数,并通过扩散系数推算微乳粒径的变化规律。研究表明,随着表面活性剂SDS浓度增加,粒径减小;随着正丁醇的增加,粒径减小;正辛烷的量对粒径影响不大。使用动态激光光散射法对实验结果进行验证,发现当电活性物质Fc全部溶于油相中时,两种方法测定结果基本相符;但随着正丁醇浓度增大,粒径是增大的。Fc在微乳液滴油核外的溶解度增大,导致测量误差增大。     

Microemulsion microstructure and interfacial curvature

The typical phase behavior of microemulsion systems undergoing phase inversion is briefly reviewed. As a model system H₂O-n-octane-C₁₂E₅ is studied with various experimental techniques. The occurring microstructures are visualized by freeze fracture electron microscopy and the corresponding domain sizes are quantified by small-angle neutron scattering. From the variations of the domain sizes the mean and Gaussian curvatures of the interfacial film with temperature are determined. It is found that the mean interfacial curvatureH changes gradually and nearly linearly with temperature from positive (Winsor I) to negative (Winsor II), passing through zero for bicontinuous microemulsions where these contain exactly equal volume fractions of water and oil. There the interfacial tension between bulk water-and oil-rich phases passes through an extreme minimum. Quantitative knowledge of the curvatures permits the measurements of interfacial tensions between the bulk phases to be discussed in terms of the relative contributions of bending energy and entropy of dispersion.     

Microemulsion Polymerization of Methyl Methacrylate

The microemulsion polymerization of methyl methacrylate was studied. The effects of feeding modes on the structure and the properties of the obtained polymer microlatex were investigated by measuring the conversion, the transmittance and the refractive index of the latex, and by measuring the particle size, the molecular weight and the glass transition temperature (T_g) of the polymers. The results show that compared to the batch feeding mode, the semi-continuous feeding mode is more favorable to form a PMMA microlatex with a higher transmittance, a smaller particle size, a higher molecular weight and a higher T_g. And the obtained PMMA microlatex has a 30％—40％ (mass fraction) polymer content, a 0. 03 emulsifier/water weight ratio, a 0. 05 emulsifier/monomer weight ratio and a 17 nm average particle diameter, which is very important for the industrialization of the microemulsion polymerization technique.