微乳液相行为和微观结构的研究

用正交试验法求得阳离子表面活性剂双十八烷基二甲基氯化铵(DOD-MAC)/阴离子表面活性剂十二烷基硫酸钠(SDS)/正丁醇/正庚烷/盐水体系中相微乳液形成的最佳配方:W_(DODMAC):W_(SDS)=1:4～1:5;C_(n-butanol)%=11.0～12.0;C_(NaCl)%=3.25附近.研究了盐浓度、DODMAC和SDS复配比例、正丁醇浓度(1.0%～14.0)%以及酸种类(正丙醇、正丁醇和正戊醇)对微乳液相态、超低界面张力(γ_(mo),γ_(mw))、最佳含盐度(S)和盐宽(△S)的影响,得到了微乳液相行为的一些规律.并用FT-IR,ESR和冷冻蚀刻方法研究了中相微乳液微观结构,3种方法均表明中相微乳液随着含盐度增加,微观结构经历o/w型到B.C.再到w/o型转变.中相微乳液分子组织形态的有序分布规律,有助于构作微乳液体系的模型,有助于对中相微乳液微观结构认识及阐明微乳液微观结构与宏观特性之间关系.     

SDS-正戊醇与SDS-正丁醇微乳体系相行为模拟

利用净平均曲率模型重现了以十二烷基硫酸钠(SDS)为表面活性剂,正丁醇和正戊醇为助剂,短碳链烷烃的相行为和增溶参数的变化情况。模拟了Winsor相图及最佳增溶参数曲线,并和实验进行了对比,与实验结果吻合的较好,并且发现在相同表面活性剂和助剂下,油越轻,增溶量越大,采用正戊醇做为助剂增溶轻油的能力约为采用正丁醇的3倍。在表面活性剂用量相差不大,助剂量相同的情况下,出现中相所需的盐度都是正己烷正庚烷正辛烷正十二烷,以正戊醇为助剂所需的盐度远小于以正丁醇为助剂所需的盐度。     

CTAB反相微乳体系的相行为研究

实验绘制了系列十六烷基三甲基溴化铵(CTAB)+正丁醇+正己烷+水(或CaCl2水溶液)拟三元体系相图。分别研究了正丁醇的添加比例和CaCl2水溶液的浓度对微乳区域的影响,发现随着正丁醇的相对比例逐渐增大,拟三元体系中微乳区的面积逐渐减小,表明过多增加正丁醇的量不利于微乳相的形成;发现总体上随着CaCl2水溶液摩尔浓度的增加,拟三元体系中微乳区的面积逐渐减小,表明强电解质的加入对微乳相影响较大,较高浓度的CaCl2会使部分CTAB失去表面活性而难以形成微乳液,导致微乳相区域逐渐减小。实验测定了电导率随水(或CaCl2水溶液)含量变化的规律,依据电解质理论探讨了微乳液的微观结构,并通过选择一定R0值的CaCl2微乳液与等摩尔的碳酸钠水溶液反应制备了球形纳米碳酸钙粒子。     

阴/阳离子表面活性剂复配体系的中相微乳液研究

阴离子表面活性剂双-2-乙基己基磺化琥珀酸钠(简称AOT), 和阳离子表面活性剂十六烷基三甲基溴代铵(简称CTAB), 在有醇、正辛烷、盐水存在的情况下,能形成多相微乳液。本文系统地研究了阴/阳离子表面活性剂配比、醇的种类、醇的浓度对该体系的中相微乳液的形成及特性的影响, 得到了中相微乳液的特性参数(最佳含盐量S^*, 最佳中相微乳液体积V^*, 界面张力r~E、盐宽△S等)。这些性质对与阴/阳离子表面活性剂复配体系, 三次采油及日用化工上的应用开发具有重要意义。最后还开展单独阴离子表面活性剂体系和阴/阳离子表面活性剂复配体系进行了比较, 得到一些有价值规律, 并从理论上进行了探讨。     

CTAB/C4H9OH/C7H16/H2O体系中w/o型微乳液的导电活化能

通过测定不同温度时CTAB/C4H9OH/C7H16/H2O体系中w/o型微乳液的电导率计算了体系的导电活化能。研究了活化能随含水量的变化规律。发现活化能随含水量的变化与微乳液出现渗滤现象有关。讨论了表面活性助剂与表面活性剂的质量比km及起始含油量R对峰值活化能Ea,max的影响。     

CTAB反相微乳液中水辛烷分子的自扩散研究

利用电导测量确定了CTAB/正丁醇/正辛烷/水四组分体系的相态,在反相微乳液区有明显的渗滤现象,通过脉冲梯度场核磁共振方法研究了反相微乳液中水和辛烷分子的自扩散行为,采用双指数拟合得出辛烷的自扩散系数。对于体系中出现的渗滤现象以及水和辛烷分子自扩散系数反常的原因,从分子水平上进行了解释。水和自扩散系数(2～7×10^-10m·s^-1)比一般文献值高,其原因：一是水在油相中有较大的溶解度;二是渗滤现象的存在,由于液滴间相互作用的增强和：粘性“碰撞而导致液滴的融合,以及由此而形成的瞬时水相连续通道,使水的自扩散系数增大。而辛烷自扩散系数比一般文献值小,则是由于在微乳液液滴的栅栏中表面活性剂分子烃链与辛烷分子间范德华引力所造成。     

CTAB反相微乳液中水辛烷分子的自扩散研究

利用电导测量确定了CTAB/正丁醇/正辛烷/水四组分体系的相态,在反相微乳液区有明显的渗滤现象,通过脉冲梯度场核磁共振方法研究了反相微乳液中水和辛烷分子的自扩散行为,采用双指数拟合得出辛烷的自扩散系数。对于体系中出现的渗滤现象以及水和辛烷分子自扩散系数反常的原因,从分子水平上进行了解释。水和自扩散系数(2～7×10^-10m·s^-1)比一般文献值高,其原因：一是水在油相中有较大的溶解度;二是渗滤现象的存在,由于液滴间相互作用的增强和：粘性“碰撞而导致液滴的融合,以及由此而形成的瞬时水相连续通道,使水的自扩散系数增大。而辛烷自扩散系数比一般文献值小,则是由于在微乳液液滴的栅栏中表面活性剂分子烃链与辛烷分子间范德华引力所造成。     

丙烯酸酯及苯乙烯微乳体系的相行为及微乳聚合

甲基丙烯酸甲酯;十二烷基磺酸钠;十二烷基磺酸钠;丙烯酸酯及苯乙烯微乳体系的相行为及微乳聚合     

CTAB/正丁醇-正辛烷-水和盐水的拟三元体系相图及微乳液微观结构的电导研究

绘制了CTAB/正丁醇-正辛烷-水和Al(NO₃)3(或Na2WO4)盐水拟三元体系的35℃相图.用电导法并结合电解质理论讨论了微乳液的微观结构,将整个微乳液单相区分为W/O微乳区、O/W微乳区和B.C.双连续区,并且用渗滤理论确定了一个分散相质点为W/O球状结构的反胶团微乳液区.     

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。     

TEM研究苯乙烯微乳液聚合机理

用透射电镜(TEM)对苯乙烯(St)/十二烷基硫酸钠(SDS)/正戊醇/水的O/W微乳液体系在反应前、聚合过程中和反应结束后等不同时间里进行观察,并测定苯乙烯微乳液聚合前后粒径的大小,根据粒径大小的变化研究苯乙烯微乳液聚合成核机理,发现其成核位置主要是在胶束和单体微珠滴里。此外,还发现SDS/St的质量比越大,相对分子质量越低。     

青霉素钾对微乳液增溶作用的影响

层状液晶;青霉素钾对微乳液增溶作用的影响     

Solubilization of Styrene and Acrylamide Monomers in Microemulsions

Abstract

Phase diagrams of sodium dodecyl sulfonate (DS)/n‐butanol/styrene/water systems with variable amounts of styrene were constructed at 40°C, and the effects of styrene on microemulsion stability were studied. The solubilization of styrene in these O/W microemulsion systems was investigated by ¹H NMR methods. The results show that the solubilization site shifts from the palisade layer to the inner core of microemulsion droplets when the molar fraction of styrene reaches 0.312. The solubilization of acrylamide in cetyltrimethylmethyl ammonium bromide (CTAB)/n‐butanol/10% n‐octane/water reverse microemulsions (W/O) was studied with a ¹³C NMR method. It was found that the acrylamide was mainly solubilized in the Stern layer of droplets at low acrylamide levels. However, when the mole fraction of acrylamide approaches 0.428, the acrylamide penetrates into the palisade layer and is distributed along the hydrocarbon chain of the surfactant.     

Reactivity Ratios for Microemulsion Copolymerization of N-butyl Maleimide and Styrene

The oil-in-water microemulsion containing N-butyl maleimide(NBMI, M1) and styrene(St, M2) was prepared. The complexation properties of NBMI and St in microemulsion were investigated by means of 1H-NMR. With the participation of charge-transfer complex(CTC), four reactivity ratios and the relative reactivity of free monomers and CTC were obtained. The result was compared with that measured by Mayo-Lewis method.     

Reactivity Ratios for Microemulsion Copolymeriration of N-butyl Maleimide and Styrene

IntroductionReactivityratioscanofferthemessageofrelativereactivityofcomonomers.TWomonomerreactivityratioscanbeacquiredfromtheend-groupmodelproposedbyMayoandLewis,howevef,thereareonlyapparentreactivityratiosavailablefromthiskineticmodelwhencharge-transfercomplex(CTC)participatesinthecopolymerization.Therefore,thecopolymeriZationinwhichCTCexistsisworthyoffurtherresearch.Sofar,therearethreekineticmodelsofcopolymerizationwiththeparticipationofCTCinall,namely,SeinerandLittmodel',Shirotamodel…     

Hydrotrope‐Solubilization Action of Urea in CTAB/n‐C5H11‐OH/H2O System

Urea can enhance the aqueous solubility of surfactant CTAB (hexadecyltrimethylammonium bromide) when it shows the hydrotrope action. It will show the hydrotrope‐solubilization action when the solubilized amount of n‐C₅H₁₁OH in O/W microemulsion and that of water in W/O microemulsion are increased. The mechanism of the hydrotrope‐solubilization action of urea is the increase of the stability of W/O and O/W microemulsion and structural transition from the lamellar liquid crystalline phase to the bicontinuous structure.     

Studies on the Middle-phase Microemulsion of Lauric-N-methylglucamide

The phase behaviour of the middle-phase microemulsion for the quaternary system lauric-N-methylglucamide （MEGA-12）/n-butanollalkane/water has been studied with Winsor type, δ-γ, fishlike and novel ε-β fishlike phase diagrams. A series of phase inversions Winsor I （2）→Ⅲ（3）→Ⅱ （ 2 ） were observed for the three kinds of phase diagrams. The phase types, the phase volumes and the range of alcohol concentrations from the beginning to the end of the middle-phase microemulsion were obtained from Winsor phase diagram. From δ-γ, fishlike phase diagram, the physicochemical parameters, such as the mass fraction of n-butanol in the hydrophile-lipophile balanced inteffacial layer, A^s, the coordinates of the start and end points of the middle-phase microemulsion, and the solubilities of MEGA-12 and n-butanol in alkane phase were calculated. The novel ε-β fishlike phase diagram was also presented. From this kind of diagram, the above experimental phenomena were observed and the physicochemical parameters were calculated precisely. The novel fishlike phase diagram has advantages over the Winsor and δ-γ fishlike phase diagrams in the evaluation of the solubilization power of the microemulsion and calculation of the related physicochemical parameters.     

阳离子型微乳液对显色剂1—（2—吡啶偶氮）—2—萘酚的增溶作用

以光度法研究了阳离子型微乳液对显色剂１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的增溶作用，通过测定ＰＡＮ在阳离子型ＣＴＭＡＢ／ｎ－Ｃ５Ｈ１１ＯＨ／ｎ－Ｃ９Ｈ２０微乳液中的“胶束位”ｎ和结合常数Ｋ，并与相同表面活性剂胶束体系比较，探讨了微乳液对显色剂ＰＡＮ的增溶作用。     

CTAB反相微乳液的稳定条件与纳米WO3的制备

以CTAB(十六烷基三甲基溴化铵)/正丁醇/正辛烷/钨酸钠水溶液构制反相微乳体系,通过测定体系电导率的方法确定相点并绘制反相微乳区拟三元相图。考察了该体系在不同条件下稳定存在的组成范围,选取实验最佳条件制备出纳米WO3。结果表明,表面活性剂与助表面活性剂的比、钨酸钠溶液的浓度对该反相微乳体系稳定区域的影响较大,当m(CTAB)∶m(正丁醇)=1∶2,钨酸钠浓度为0.05～0.08 g/mL时,体系有较大的反向微乳区,且当m(CTAB 正丁醇)∶m(正辛烷)=2∶3时,体系有最大溶水量;温度对该体系稳定区域的影响不大。在最适宜条件下,以0.08 g/mL的钨酸钠微乳液与盐酸微乳液,在40℃的水浴中反应7 h,制备出平均粒径约30 nm的WO3纳米粒子。