制备纳米BaSO4的W/O微乳液体系组成及稳定性

以TritonX 10 0 正己醇 环己烷 水制成W O微乳反胶团体系 ,通过测定体系的电导率和观察液晶相的出现确定相点绘制了各体系的拟三元相图 ,研究了温度、盐浓度和油相组分对W O微乳液体系稳定性的影响 .实验发现助表面活性剂与表面活性剂的配比对微乳液的稳定性有显著影响 .随着温度的升高 ,W O微乳液稳定区域减小 ,可通过升高温度对微乳液进行破乳 ;与以纯环己烷为油相的体系相比 ,油相中含有少量正己烷的体系具有更优异的性质 .所得结果为利用该W O微乳液体系制备纳米颗粒提供了基础数据     

CTMAB微乳体系的相行为研究

进行了CTMAB/正丁醇/环己烷/水微乳液体系相行为的研究。通过制备微乳液,总体了解W/O型微乳液的相应性质,对制备过程中的反应条件做逐一的比较,包括CTMAB微乳体系当中表面活性剂的选择,助表面活性剂的选择,油相的选择,最终选择出最佳的配比。当CTAB与正丁醇的质量比为1∶1时,体系对水的增溶量最大,并且确定(CTAB+正丁醇)与环己烷的质量比为1.5∶1,制备温度选为20℃、p H值选为8时,CTMAB微乳体系有较好的温度和酸碱度。     

基于相图法的W/O型微乳液体系稳定性分析

以辛基苯基聚氧乙烯醚(TX-10)、十二烷基磺酸钠(SDS)和十六烷基三甲基溴化铵(CTAB)为表面活性剂,以正戊醇、正己醇和正庚醇为助表面活性剂,以正戊烷为油相,制备了油包水型(W/O)微乳液.用相图法分析了微乳液体系的热力学稳定性,计算了水核半径的大小,并考察了影响微乳液W/O区域范围的各种因素.结果表明:这几种微乳液体系在实验条件下能自发形成:微乳液的水核半径处于纳米量级,可作为制备纳米粒子的超微反应器;以TX-10为表面活性剂时,水核可以包容更多的水分子,微乳液的W/O区域较大;而以CTAB为表面活性剂时,由于其极性头之间的空间和静电排斥作用强,微乳液的W/O区域最小;以硝酸镧溶液作为分散相时,微乳液的W/O区域变化较小;随着温度的升高,微乳液的W/O区域显著减小.     

纳米氧化铈的制备及其反相微乳液的稳定条件

探讨了用于制备氧化铈纳米粒子的反相微乳体系组成及稳定性,以溴化十六烷基三甲基铵/正丁醇/环己烷/水构成了用于制备纳米氧化铈的W/O微乳液,通过测定体系的电导率的方法确定相点,绘制了溴化十六烷基三甲基铵和正丁醇-环己烷-水反相微乳区拟三元相图.结果表明,表面活性剂与助表面活性剂质量比,即溴化十六烷基三甲基铵与正丁醇的质量比等于1.6时为制备纳米粒子的最佳值,加入硝酸铈会使微乳液的区域减小,随着温度的升高微乳区域略微减小.按实验确定的条件,制备出纳米氧化铈,XRD分析结果表明,纳米氧化铈粒径为19~22 nm.     

含非离子表面活性剂吐温-80的微乳液结构研究

采用非离子表面活性剂吐温-80,以石油醚为油相,正丁醇为助表面活性剂来制备微乳液。用稀释法测定并计算了Tween-80/石油醚/正丁醇/水体系O/W型微乳的结构参数。测量微乳液体系在15~30℃温度范围内的pH及电导,考察温度对微乳液体系的影响。向微乳液体系中加入PVP,测量体系的电导和接触角,考察水溶性高分子对微乳液体系的影响。结果表明微乳液体系的电导随温度的上升而变大,相同温度时,加入PVP会使体系的电导变大,接触角变小。     

反相微乳液法制备负载型Pt基催化剂及其选择加氢活性

采用反相(W/O)微乳液法制备负载型Pt基催化剂,以间氯硝基苯(m-CNB)选择加氢反应为探针,考察微乳液组成、助表面活性剂和油相种类、还原剂用量及载体种类等制备参数对催化剂活性的影响,并对Pt粒子及催化剂进行TEM表征。结果表明：选择十六烷基三甲基溴化胺(CTAB)/正丁醇/环己烷/H2PtCl6溶液的W/O微乳体系...     

TX-100反相微乳液体系稳定性的研究

以最大增容水量为考察目标,研究了温度、HLB值和助表面活性剂含量对TX-100/正己醇/环己烷反相微乳液体系稳定性的影响,绘制了该反相微乳体系的拟三元相图,并用电导率法讨论了微乳液的微观结构。结果表明,当温度t=25℃,TX-100与正己醇质量比为1.5时,体系具有最大的增容水量;在不同的增容水量时体系存在3种不同的微乳区域,即油包水、水包油和油水双连续区域。     

吐温-80/对二甲苯/1,2-丙二醇水溶液拟三元体系相图研究

采用稀释法绘制了吐温-80/对二甲苯/1,2-丙二醇水溶液拟三元体系的25℃相图,利用电导法测定了其中微乳液的微观结构。结果表明：体系中包含单相微乳区、两相分层区、白色乳液区三部分,其中微乳区又分为油包水（W/O）微乳区、双连续区（B.C.）、水包油（O/W）做乳区三部分。另外。考察了醇水溶液中醇的质量分数及温度对撒乳区域范围的影响,发现醇的质量分数越高,微乳区域范围越大;温度越高,O/W微乳区域范阻越小。经稳定性实验表明：O/W微乳液稳定.     

水基性透明液体剂型的加工、性能和差异(Ⅱ)

4 微乳剂 早在20世纪40年代,Hoar和Schulman等人发现油-水混合物借助表面活性剂可以自发地形成透明的分散体系,由于所形成的液滴粒径非常小,后来将这种体系命名为微乳液.此后证明,它是一个热力学上稳定的、均相的水包油型乳液可溶体系,加工的微乳液剂型即为微乳剂. 微乳液存在3种结构类型,即O/W型、W/O型和双连续相结构(也称为中间相微乳型).这3种类型可以在一定条件下互相转变[10].农药上的微乳剂大都为以水为连续相的O/W型乳液.     

O/W型微乳液的制备及稳定性的研究

以Span80和Tween20作为复合表面活性剂,环己烷作为油相,采用滴加法在高速剪切作用下制备了性能稳定的O/W型微乳液。分别研究了Span80/Tween20质量比、Span80/Tween20用量、水滴加量、环己烷用量、乳化温度等因素对微乳液平均粒径的影响。当Span80/Tween20质量比为1∶1,Span80/Tween20用量16g,水滴加量30g,乳化温度30℃,环己烷用量5g时,制备的微乳液平均粒径最小(为50.15nm),且分布均匀。其稳定性研究结果表明:微乳液经过10000r/min高速离心能保持很好的稳定性,放置60d后,10000r/min高速离心依然稳定存在。     

0.716 H2O+0.284 n-C4H9OH二元体系的热力学性质

用全自动低温绝热量热计测定了水和正丁醇二元体系（0.716 H₂O+0.284 n-C₄H₉OH）在78～320 K温区的摩尔热容C_p,m.建立了C_p,m与温度T的函数关系.结果表明,该水和正丁醇二元混合体系在（111.9±1.2）K发生玻璃化转变,在（179.26±0.77）K和（269.69±0.14）K发生分别对应正丁醇和水的固 液相变.获得了水的相变焓和相变熵.计算了以298.15 K为基准的混合物的热力学函数.     

Characterization of Water/Sucrose Laurate/n-Propanol/Allylbenzene Microemulsions

Water/n-propanol/sucrose laurate/allylbenzene micellar systems were formulated and applied in the isomerization of allylbenzene in the presence of heterogenized derivatives of some platinum group catalysts. The ratio (w/w) of n-propanol/surfactant studied herewith was 2/1. Temperature insensitive microemulsions were found. The microemulsions were characterized by the volumetric parameters, density, excess volume, ultrasonic velocity, and isentropic compressibility. The densities increase with increases in the water volume fraction. Excess volumes of the microemulsions decrease for water volume fractions below 0.2, level off for water volume fractions between 0.2 and 0.6 then increase for water volume fractions above 0.6. Excess volumes of the studied micellar systems increase with temperature. Isentropic compressibilities increase with temperature for water volume fractions below 0.8 and decrease for water volume fractions above 0.8. Structural transitions from water-in-oil to bicontinuous to oil-in-water occur along the microemulsion phase. The particle hydrodynamic diameter of the oil-in-water microemulsions at the 0.95 water volume fraction was found to decrease with temperature.     

Soybean oil microemulsions with oleic acid/glycols as cosurfactants

The preparation of biocompatible microemulsions of soybean oil in systems made of anionic surfactant, oleic acid, water, and several glycols was considered. The selected glycols were ether derivatives (methyl, ethyl, dimethyl, and diethyl ether) of ethylene glycol and diethylene glycol. The study was performed using pseudoternary phase diagrams in which the three apexes were occupied by soybean oil, a combination of surfactant/oleic acid, and a combination of water/glycol, respectively. The widest regions of microemulsions were obtained for systems containing methyl ether and especially ethyl ether of both ethylene glycol and diethylene glycol. The two latter compounds allowed the preparation of oil-in-water, bicontinuous, and water-in-oil microemulsions with final surfactant contents of 3–4%.     

微乳法合成磷酸钙纳米纤维及其机理探讨

分别以非离子表面活性剂（C₁₂E₈）和阳离子表面活性剂（CTAB）为模板剂,在反微乳体系中制备了磷酸钙纳米纤维.在水/C₁₂E₈/环己烷体系中纤维长约为325 nm,宽约为13 nm,为无定形态;在水/CTAB/环己烷体系中纳米纤维的长度>500 nm,宽度约为14 nm,结晶较完全.两种表面活性剂的作用机理完全不同：在非离子表面活性剂体系中,表面活性剂主要起到“微反应器”的作用;而在阳离子表面活性剂中,表面活性剂主要起到“生长引导剂”作用.     

Phase Behavior of Glycerol Trioleate‐Based Ionic Liquid Microemulsions

Glycerol trioleate‐based ionic liquid microemulsions are promising biolubricant alternatives. This study presents the formation and the phase behavior of glycerol trioleate‐based ionic liquid microemulsions. Areas of the single‐phase domain were calculated to illustrate the phase‐forming capacities of the designed systems. The effects of ionic liquid anions and cations, oxyethylene groups’ number of surfactant, mass ratio of surfactant to co‐surfactant, chain length of co‐surfactant, and temperature on the phase behavior and phase‐forming capacities of glycerol trioleate‐based ionic liquid microemulsions were investigated using pseudo‐ternary phase diagrams. The results showed that the phase‐forming capacities of glycerol trioleate‐based ionic liquid microemulsions with different ionic liquids were Tf₂N^?‐based > PF₆^?‐based > BF₄^?‐based, OMIM⁺‐based > HMIM⁺‐based > BMIM⁺‐based > EMIM⁺‐based. The designed systems contained ionic liquid‐glycerol trioleate amphiphilic balance; thus, glycerol trioleate‐surfactant micelles achieved the maximum solubilization capacity for the ionic liquid when the surfactant had approximately five oxyethylene groups with a surfactant to co‐surfactant mass ratio of 4:1. Moreover, increasing the temperature and the aliphatic chain length of co‐surfactant from C2 to C6 enhanced the ability of glycerol trioleate and ionic liquids to form microemulsions.     

Preparation of high concentration ceramic inks for forming by jet-printing

Reverse microemulsions (RMs) were applied to preparing ceramic inks for jet-printing forming. First of all, different RM systems were chosen and optimized in order to obtain high concentration ceramic inks. Triton X-100/co-emulsifier/oil/water RM system was systematically investigated. Different kinds and different amounts of co-emulsifier and oil phase were selected and mixed to form RM after intensively stirring. RM region in the quasi-ternary phase diagram of the system was determined. It was shown that Triton X-100/n-hexanol/cyclohexane/water RM system exhibited an excellent behavior in enhancing water-dissolving amount. The best composition for the maximum water content was given. Zirconium oxychloride solution and ammonia solution were then added to the above system respectively. After stirring intensively, two clear RMs were obtained. Then ZrO₂ ceramic inks were readily prepared by reaction after mixing the two RMs uniformly. The physicochemical properties of ZrO₂ ceramic inks, such as viscosity, surface tension, conductivity, stability etc. were determined. The particle size and morphology of ZrO₂ nanoparticles in the RM were observed by TEM.     

六氨氯化镁热解过程及其非等温动力学

利用热重（TG）分析技术对六氨氯化镁的热分解过程及动力学进行了研究,考察了六氨氯化镁在4、7、10、13、16 K·min^-1线性升温速率和空气气氛下热分解机理,六氨氯化镁热解过程分为3个阶段。提出了一种整体优化的多升温速率迭代的等转化率求取活化能方法,采用该方法,得到六氨氯化镁热解3个阶段的活化能分别为51.38、64.70、73.55 kJ·mol^-1。采用整体优化的多升温速率等温法确立了六氨氯化镁热解3个阶段的热解机理函数与指前因子：第1步反应的热解机理属于固体相边界反应机理（n=1/4）,指前因子为3.281×10⁵ s^-1;第2步反应的热解机理属成核与生长机理（n=1.8）,指前因子为5.624×10⁶ s^-1;第3步反应属化学反应机理（1.5级反应）,指前因子为5.862×10⁵ s^-1。     

Cosurfactant effects on the polymerization of vinyl acetate in anionic microemulsion media

The polymerization of vinyl acetate at 60 °C in microemulsions stabilized with the anionic surfactant, Aerosol OT, with or without cosurfactant (n-butanol) is examined. Partial phase diagrams at 60 °C show that the addition of n-butanol enhances the one-phase microemulsion region. Results indicate that the reaction rate is not affected by the presence of the alcohol. However, average molar masses are smaller although particles are bigger throughout the reaction compared to those values obtained in the absence of n-butanol. An explanation for these results is presented.     

SA/NaCS-CaCl2/PMCG微胶囊固定化枯草杆菌HL-1发酵生产纳豆激酶

制备了海藻酸钠/纤维素硫酸钠-CaCl₂/聚亚基二胍氯化氢微胶囊（SA/NaCS-CaCl₂/PMCG微胶囊）,并以该微胶囊固定化培养枯草杆菌HL-1用于发酵制备纳豆激酶,考察了PMCG对枯草杆菌生长的影响,比较了微囊化培养与游离培养过程中的菌体生长、耗糖速率以及纳豆激酶产物分泌能力.最后经过连续6批培养,酶活可达到2465 IU•ml^-1,是游离培养过程的3倍.