十四烷基芳基磺酸盐形成的分子有序组合体

以表面张力法、碘光谱法、水增溶法和相态图法研究了自制的三种十四烷基芳基磺酸盐在不同条件下形成的分子有序组合体(胶束、反胶束和微乳液),并考察了分子结构、溶剂、无机盐和短链醇等对其的影响.结果表明:增加十四烷基芳基磺酸盐分子亲油基支化度,不利于其在水溶液或混合极性溶剂(乙二醇-水)中形成胶束而有利于其在非极性溶剂正庚烷中形成反胶束;溶剂极性的降低,促使表面活性剂溶液由胶束溶液→单体溶液→反胶束溶液转变;无机盐或短链醇的加入促进了水溶液中胶束的形成,且反离子价态数或醇烷基碳原子数越大,越有利于胶束形成;无机盐浓度的增加导致表面活性剂/正丁醇/正辛烷/NaCl/水形成的微乳液体系在一定温度下发生由WinsorI→WinsorIII→WinsorII型的转变.     

混合表面活性剂在非极性溶剂中的聚集行为

表面活性剂在非极性溶剂中的聚集行为比在水溶液中复杂得多. 水溶液中表面活性剂有一明确的临界胶束浓度(CMC),而在非极性溶剂中至今对CM C概念仍有怀疑^[1], 但已有多种手段如染料增溶法、水增溶法、光散射法、荧光偏振、紫外和核磁共振谱等证实并测定了非极性溶剂中 CMC 的存在^[1～5]. 表面活性剂在非极性溶剂中以非离子化状态存在, 其缔合主要靠两亲分子之间的偶极-偶极以及离子对相互作用, 那么在一种表面活性剂溶液中加入另一种表面活性剂, 即表面活性剂的复配, 必然对其聚集行为产生重大影响, 但迄今为止, 尚未见关于混合表面活性剂在非极性溶剂中聚集行为的报道. 本文采用碘光谱法和水增溶法测定了阴离子表面活性剂AOT 和非离子表面活性剂 Brij30 混合后在正庚烷中形成反胶束的 CMC, 以期考察表面活性剂的复配对其聚集行为的影响。     

非水介质中的酶催化反应

介绍了非水溶剂体系中的酶催化反应，主要是反胶束体系中酶催化反应和脂肪酶催化反应的新研究成果，评述了各溶剂体系中酶的结构，动力学特征，稳定性及活性。     

混合反胶束的电导与微结构研究

反胶束是两亲分子在非极性溶剂中形成的一种有序组合体，在医药、化工、采油、胶束催化及酶催化等领域中有重要应用．与胶束溶液相比，人们对反胶束的形成与结构的了解至今仍不充分．特别是对于由混合表面活性剂形成的反胶束的研究几乎无人涉及．本文采用动态光散射、电导及荧光光谱等手段对阴离子表面活性剂AOT与非离子表面活性剂形成的混合反胶束进行了研究，旨在探讨利用表面活性剂的复配来调节和控制反胶束的结构和性能．亚实验部分二异辛基磺化琉璃酸钠（AOT，Sigma公司）；Brij30为含4个氧乙烯基（EO基）的十二碳醇（AcrosOrgani…     

荧光探针技术研究共溶剂对PEO-PPO-PEO嵌段共聚物溶液胶束的形成及内部结构的影响

选择了甲醇、乙醇、正丙醇、乙二醇、乙二胺、乙醇胺及２ 甲氧基乙醇等七种包括单官能团和双官能团共溶剂、与水组成混合溶剂，并利用荧光探针技术研究了共溶剂对环氧乙烷 环氧丙烷 环氧乙烷（ＰＥＯ ＰＰＯ ＰＥＯ）共聚物水溶液胶束形成及其结构的影响，结果表明，一些共溶剂与水和共聚物ＰＰＯ段都具有较好的混溶性，使形成胶束的ＣＭＴ升高，而其它共溶剂的引入则使得形成胶束的ＣＭＴ降低．从共溶剂对所形成胶束的微结构影响看，能与共聚物链有较强作用的双官能团的共溶剂和有较小分子尺寸的共溶剂有利于使形成的胶束具有较紧密的结构，在此条件下，形成胶束的紧密程度决定了胶束内微极性的大小，而与引入共溶剂的极性大小关系不大．     

胶束液相色谱法

表面活性剂分子是一种两亲分子,其聚集体称为胶束,具有增溶作用。许多疏水性物质都能增溶于其非极性区。胶束的这种特殊性质,近年来被广泛应用于多种分离与分析方法中。如胶束增溶分光光度法,以及应用胶束以改进滴定分析、光谱分析和电化学分析等。本文将着重介绍胶束液相色谱法(Miccllar Liquid chromatography,MLC)。     

核糖核酸酶在DAB-环已烷反胶束溶液中的活性

表面活性剂在有机溶剂中形成的反胶束可以增溶大量的水分子，很多水溶性的物质又可溶解在反胶束的核心水团当中，这些都已是不争的事实［1］．酶在反胶束中的溶解对蛋白质的萃取分离，生物合成等方面有着十分广阔的应用前景，已引起了广泛的注意，文献逐年增加［2－4］．核糖核酸酶A（RNaseA）分子量较小，性质稳定，活性的测定简便易行，很适于作为反胶束－酶体系的研究对象，但大部分研究集中在阴离子表面活性剂AerosolT（AOT）的反胶束体系上，而对其它表面活性剂反胶束－酶体系的研究很少［5，6］．Papadimitriou等曾发现．糜蛋白酶…     

卵磷脂反胶束体系中β-1,4葡萄糖苷酶的研究

测定了水、醋酸缓冲液和水杨苷醋酸/醋酸钠缓冲液在水/PC/庚烷-正丁醇反胶束体系中的饱和增溶量,利用UV、FT-IR和NMR等技术考察了增溶到水/PC/庚烷-正丁醇反胶束体系中的β-1,4葡萄糖苷酶及水杨苷的结构变化,并研究了β-1,4葡萄糖苷酶在水/PC/庚烷-正丁醇反胶束中的活性.发现了β-1,4葡萄糖苷酶在水/PC/庚烷-正丁醇反胶束中遵循米氏反应,最大反应速度vmax为1.475mg·min-1,是其在水中的11.8倍,米氏常数Km为0.389mg·mL-1,是其在水中的1/25.β-1,4葡萄糖苷酶在水/PC/庚烷-正丁醇反胶束中表现出的低底物浓度下的高催化速度,是微乳的界面发生的相互作用改变了β-1,4葡萄糖苷酶的构象,增加了底物水杨苷的浓度,PC极性头部-N+(CH3)3正离子作用水杨苷糖苷键的氧有利于糖苷键的断裂等因素造成的.     

胶束介质中丁二酮增溶位点的室温燐光碎灭法研究

采用丁二酮室温光猝灭法研究了胶束介质中丁二酮的增溶位点，通过研究4种不同荷电和不同亲水亲脂性的光猝灭剂以及盐效应等对Stern－Volmer常数的影响，表明了二酮在SDS、CTAB的胶束中是增溶在胶团的栏栅并靠近离子头基一侧和头基／水界面附近，而在CTAB胶束中更加趋向于胶团外部头基附近．     

反胶束体系中有机染料PDS对TiO_2纳米粒子的表面修饰

反胶束法制备纳米粒子是 2 0世纪 80年代兴起的研究领域[1] .反胶束是指表面活性剂在非极性溶剂中定向排列而自发形成的聚集体 [2 ] ,反胶束的“水池”是一种特殊的纳米空间 ,以此作为微反应器 ,通过控制含水量 W0 ( W0 =[H2 O]/[Surft.],即水与表面活性剂的摩尔比 )和选择不同的表面活性剂种类及浓度可以获得单分散的粒径小于 1 0 nm的微粒 [3～ 5] .Ti O2 作为一种典型的光催化剂 ,由于其化学性质稳定、氧化还原性强 ,且具有抗光阴极腐蚀性、难溶、无毒、成本低等特点 ,在有机污染物的去除 ,废水处理等方面具有广阔的应用前景[6 ] .而…     

脂肪酸十二烷基铵在四氯化碳中的聚集行为

通过碘光谱法和对水的增溶研究了乙酸十二烷基铵(DAA)、丙酸十二烷基铵(DAP)和丁酸十二烷基铵(DAB)在四氯化碳中的聚集作用; 碘光谱测得的(cmc)~I约比水增溶法测得的(cmc)~W低一个数量级。可能因为碘光谱法测得的是开始发生聚集时的cmc, 这时聚集体较小, 对水无增溶能力; 只有当聚集体随浓度升高而长大到一定程度时, 才能开始增溶水。实验表明, DAA, DAP和DAB的反胶束对水的饱和增溶能力, 分别相当于每一个表面活性分子增溶4.2, 9.4和13.5个水分子。根据球型反胶束模型, 计算了反胶束聚集数、捕集水团的半径和自由水团的半径。     

Sorption of hydrophobic molecules by organic/inorganic mesostructures

During the synthesis of micelle-templated silica an intermediate inorganic/organic mesostructure is obtained with an hexagonal arrangement of channels filled by surfactant molecules. The ability of such a mesostructure to solubilize organic molecules from an aqueous solution was investigated. To that end, silica/cationic surfactant mesostructures were prepared under various conditions and their stability toward surfactant release in water was first compared in order to select materials as stable as possible. Swelled mesostructures were also used. The sorption from solution of hydrophobic molecules was then studied. The affinity of the molecules for the mesostructures is directly related to their hydrophobic character as it is derived from their octanol/water partition coefficient. A cooperative effect between hydrophobic molecules and the cationic surfactant that stabilizes the surfactant inside the mesostructure was observed. Interaction energies between the solutes and the mesostructures were determined by microcalorimetry. They varied in accordance with the hydrophobic character of the molecule and, at low sorption amounts, they were of the same order of magnitude as the solubilization enthalpies in bulk micelles. When the sorption increases, the surfactant layer in the mesostructure is not allowed to swell as the free micelle does, and steric limitations in the headgroup area render sorption less favorable.     

脂肪醇和电解质对丙酸十二铵盐在四氯化碳中增溶水的影响

研究了己醇，辛醇、Ｋｕｉ醇和月桂醇对丙酸十二铵（ＤＡＰ）－四氯化碳反胶束溶液增溶水和氯化钠水溶液的影响，在ＤＡＰ浓度固定时，水增溶量对醇浓度的关系出现极大值，在醇浓度相同时，长碳链醇较短碳链醇有更大的增溶水能力，在固定ＤＡＰ浓度和增溶水量最大时，氯化钠的存在将导致水溶液增溶量的显著下降，乙酸十二铵（ＤＡＡ）、ＤＡＰ和丁酸十二铵（ＤＡＢ ）的四氯化碳溶液对氯化钠水溶液的增溶量随氯化钠浓度的升高而有不     

A two-state model for selective solubilization of benzene-limonene mixtures in sodium dihexyl sulfosuccinate microemulsions

When surfactants are used to solubilize oil, the oil to be solubilized is often a mixture of components with differing properties, for example, solubilization of drug molecules in microemulsion formulations, remediation of organic polluted aquifers using surfactants, and so forth. Previous research has demonstrated that selective solubilization of one organic component over the other may occur if the organic components are dissimilar. In this research, we investigated selective solubilization from benzene-limonene mixtures in Winsor type I and III microemulsion systems containing water, sodium di-n-hexyl sulfosuccinate, and NaCl. The effect of the oil phase composition and the electrolyte concentration on the selectivity was studied. It was found that the selectivity toward benzene was highest at low electrolyte and benzene concentrations, decreasing as the electrolyte or benzene concentration increased. The results are discussed on the basis of the two-state solubilization theory and by correlating the curvature of the surfactant film in the microemulsion with changes of the electrolyte concentration and the oil phase composition. A simple mathematical model is developed for the selectivity, which combines the two-state solubilization theory and the net-average curvature model of microemulsion solubilization to yield close agreement with the experimental data.     

Styrène solubilization in micelles of dodecyltrimethylammonium hydroxide

 The solubilization of styrene molecules in aqueous dodeciltrimethylammonium Hydroxide (DTAOH) solution was studied by UV-Vis spectroscopy. In short, fully ionized DTAOH aggregates the styrene molecules in the micelle double layer, oriented with their vinyl group to the micelle core and the aryl ring to the intermicellar solution. At increased surfactant concentration, when the aggregates incorporate counterions in their Stern layer, the orientation is maintained, but styrene molecules gradually penetrate into the micelle core as the micelle size and degree of counterion union increased, until they were completely immersed in the hydrocarbon core of rod-like micelles. Received: 6 November 1996 Accepted: 10 February 1997     

On the interpretation of solubilization results obtained from semi-equilibrium dialysis experiments

The interpretation of intramicellar solubilization data obtained from semi-equilibrium dialysis (SED) experiments is described, and methods are presented for determining equilibrium constants for the solubilization of organic species by aqueous surfactant solutions as well as activity coefficients of both the organic solute and the surfactant within the micelle. The solubilization equilibrium constant of an organic solute in an aqueous micellar solution (K) is defined as the ratio of the mole fraction of organic solute in the micellar pseudophase (X) to the concentration of the unsolubilized monomeric organic solute in the aqueous phase (c ₀). Expressions compatible with the Gibbs-Duhem equation are used to represent the concentration dependence of activity coefficients of both the solubilizate and surfactant in the micellar pseudophase; the analysis leads to calculated values of the concentrations of free and intramicellar surfactant and organic solute in both compartments of the equilibrium dialysis cell. Solubilization equilibrium constants for many amphiphiles are well correlated by the simple expressionK=K ₀(1-BX)², whereB is an empirical constant andK ₀ is the limiting value ofK asX approaches 0.     

Adsorption of octadecyltrimethylammonium chloride and adsolubilization on to cellulosic fibers

The coadsorption of different organic solutes on cellulosic fibers treated with octadecyltrimethylammonium chloride (ODTMA) has been studied. In the absence of ODTMA cellulosic fibers had little tendency to retain organic compounds. The enhanced solute incorporation was ascribed to the adsolubilization of these compounds on the aggregated domains of the adsorbed surfactant molecules at the solid/liquid interface. The specific shape of solute coadsorption isotherms indicated that the adsolubilization process may be regarded as a partition phenomenon between the aqueous bulk phase and the adsorbed surfactant aggregates. The decrease in solute uptake at the cellulose/water interface above the CMC of ODTMA was ascribed to micelle formation in the bulk solution and to the ensuing micellar solubilization of organic solutes. Preliminary experiments performed using vertical fixed bed columns showed that modified cellulosic fibers can be conveniently used as substrate for treating organic pollutants.     

Ion and water transport during lithium chloride concentration from aqueous organic solutions by electrodialysis

The concentration of lithium chloride from aqueous organic solutions with different volume concentrations of N,N-dimethylacetamide (DMAA) was studied experimentally. An extended model of the limiting electrodialysis concentration of electrolytes from mixed media was developed. The model takes into account the osmotic and electroosmotic mechanisms of the transfer of water and organic solvent, as well as the electromigration and diffusion mechanisms of the salt transfer. Using the experimental data and the extended model, we evaluated the transport parameters of the MK-40/MA-40 membrane pair in aprotic solutions of variable compositions and studied how they changed with an increase in the volume fraction of DMAA in a mixed solution. The contribution of each of these mechanisms of ion and water transport to the electrodialysis concentration of electrolyte from aqueous and organic aqueous solutions was determined. Electroosmotic transfer was found to be the main mechanism of the solvent transfer that limits the stage of the electrodialysis concentration of the electrolyte from aqueous and organic aqueous solutions.