阳离子、非离子混合表面活性剂体系在油水两相间传质过程中的相互作用

本文测定了阳离子表面活性剂（CTAB）和非离子表面活性剂（TritonX－100）在水－正庚烷中的分配系数（Co＜cmc），以及混合阳离子、非离子表活剂在水－庚烷中的分配系数（Co＜cmc）。通过分配系数和有关假定，计算出两种表面活性剂在单独和混合分配时的△GW→0、△SW→0、△HW→0值，并利用热力学函数推算出阳离子和非离子表活剂在小于临界胶束浓度时的分配过程中的分子间相互作用系数β值。     

十六烷基三甲基溴化铵/己醇体系萃取分离金

用^198Au示踪法研究了在碱性条件下,十六烷基三甲基溴化铵（CTAB） 萃取KAu(CN)2。实验考察了水相金浓度、助剂或CTAB及体系乳化等因素对金萃取分离的影响。结果表明：CTAB体系可将绝大部分金从水相萃取到有机相。随着萃入金的增加,有机相水含量减少。增加有机相己醇浓度或在相中加入少量溶菌酶,可对乳化体系起着破乳作用。当NH4SCN浓度大于3．0mol/L时,大部分有机相金能被反萃回收相（反萃率为－93％）。     

人血清白蛋白在双水相法体系中的分配规律研究

人血清白蛋白是一种重要的临床药用蛋白质。以PEG/(NH4)2SO4双水相体系萃取分离人血清白蛋白,探索人血清白蛋白在双水相体系中的分配规律。结果表明,人血清白蛋白在双水相体系中的分配系数与萃取率均随着PEG分子量的增大而增大;随PEG和(NH4)2SO4浓度的增加而增加,当PEG为19.53%、(NH4)2SO4为14.07%时达到最大;但若持续增大各相的浓度,其分配系数与萃取率又会下降;随着体系中外加盐NaCl浓度的增加而增加,在NaCl浓度为10%时达到最大。     

表面活性剂双水相分离茶多酚生产废液中的茶氨酸(英文)

Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactant two-phase system (ASTP) with cationic surfactant (CTAB) and anionic surfactant (SDS). Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant. The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP. Theanine concentration in the bottom phase increases with increasing concentration of theanine, whereas the partition coefficient and extraction rate only change a little when the concentration of theanine is above 0.2 g·L-1 . With the increase of SDS concentration, the phase ratio and the partition coefficient decrease, while the extraction efficiency of theanine increases and the concentration of theanine changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio. The temperature has a notable effect on the concentration of theanine in the bottom phase, partition coefficient and extraction rate of theanine. The increase of waste liquid decreases the phase ratio, increases the concentration and extraction rate of theanine in the bottom phase, since the protein and the saccharide enter the bottom phase with theanine.     

十六烷基三甲基溴化铵-珍珠粉相互作用及其稳定乳液的双重相转变

系统研究了阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）对生物质颗粒珍珠粉制备Pickering乳液的类型、微观结构的影响，同时解析了CTAB/珍珠粉稳定乳液从O/W型到W/O型再到O/W型的双重相转变现象。通过分散性观察、Zeta电位的测定、三相接触角和珍珠粉的荧光标记等手段深入剖析了CTAB与珍珠粉颗粒之间的相互影响。结果表明，在未添加CTAB和CTAB浓度较低时（0.01 mmol/L）时，珍珠粉能单独形成O/W型的Pickering乳液，乳化粒子为非球形且有一定聚结。当CTAB的浓度增加到0.05和0.20 mmol/L时，CTAB在珍珠粉表面吸附增强了颗粒的疏水性，润湿性的变化导致乳液类型从O/W型转变到W/O型，此时乳液的微观结构为球形，且尺寸分布较窄。随着CTAB浓度的进一步增加到0.90 mmol/L,CTAB在油水界面上取代吸附的珍珠粉颗粒，荧光显微镜观察验证了此时形成的O/W型乳液是由过量的CTAB来稳定。即通过简单地增加阳离子表面活性剂CTAB的浓度，就能实现乳液从O/W型到W/O型，再到O/W型的双重相转变。     

丙烯酰胺在聚乙二醇水溶液双水相聚合过程中的单体分配

用改进溴化法对丙烯酰胺（AM）在聚丙烯酰胺（PAM）-聚乙二醇（PEG）-H2O双水相体系中的分配进行了研究,分配系数随PEG浓度、分子量的增加而减少,随PAM浓度、分子量的增大而增大,而随温度的升高先减小后增大。并在此基础上,对AM在PEG水溶液双水相聚合过程中单体在两相的分配进行了研究,考察了PEG浓度、单体浓度、温度对聚合过程中单体分配的影响。     

PEG/（NH_4）_2SO_4双水相萃取分离茶氨酸的研究

采用聚乙二醇（PEG）/（NH4）2SO4双水相体系萃取分离生产茶多酚所得废液中的茶氨酸,考察了PEG分子量与含量、硫酸铵含量、pH、温度、加盐（KCl、KBr、KI）、茶氨酸含量对双水相及萃取分离茶氨酸的影响。结果表明,PEG/（NH4）2SO4双水相萃取分离茶氨酸的适宜条件是：PEG平均分子量为4 000,质量分数为10%,硫酸铵质量分数为15%,pH约为6,30℃。在此条件下,茶氨酸的分配系数K1=0.16,蛋白质的分配系数K2=0.28,糖类的分配系数K3=9.8,茶氨酸在下相的萃取率为89.5%,可以将茶多酚废液中的茶氨酸与糖类及其他有颜色的杂质分开。     

醇和小分子有机物二元双水相体系萃取盐酸多西环素

基于小分子醇双水相体系和小分子有机物双水相体系,建立了乙醇与丙酮和(NH4)2SO4形成的二元双水相体系萃取盐酸多西环素的新方法。研究了(NH4)2SO4浓度、pH值、温度、乙醇与丙酮用量和盐酸多西环素浓度对盐酸多西环素分配行为的影响。结果表明,体系的(NH4)2SO4浓度为41%,pH值在4.5～5.0,温度25℃,且盐酸多西环素的质量浓度70 mg/L时,萃取率可达93.61%,分配系数可达83.081。     

分子模拟十六烷基三甲基溴化铵对石油污染物在粗糙石英砂表面脱附的影响

溶剂萃取法广泛应用于石油污染土壤的修复,萃取前后土壤微观结构的改变会影响石油污染物在土壤中的迁移和传递。本文利用分子动力学模拟方法,通过在石英砂表面上构造不同的凹槽代表矿物表面粗糙的结构,研究十六烷基三甲基溴化铵（CTAB）水溶液萃取石油污染物（正十二烷）的过程。结果表明：①脱附过程的主要驱动力为凹槽外的正十二烷和CTAB分子与凹槽内正十二烷分子之间的相互作用;②凹槽的宽度减小或者凹槽的深度增加,均会增加槽内正十二烷分子的脱附难度,同时还会影响CTAB分子的促进脱附效果;③CTAB分子对石油脱附的促进效果随其浓度的增加而减弱,当持续增加体系中CTAB的含量时（不同模拟体系中的CTAB分子数量分别为0、16、32）,会抑制其促进脱附的效果。     

十二烷基聚氧乙烯(9)醚双水相体系萃取苯酚

采用十二烷基聚氧乙烯醚(AEO9)双水相胶束体系进行苯酚的萃取,考察Na2SO4和NaCl对质量浓度为50 g/L AEO9水溶液体系浊点的影响。结果表明,Na2SO4对浊点下降的影响比NaCl大,当盐的浓度均为0.6 mol/L,添加Na2SO4时浊点为28.5℃,而添加NaCl时为36.5℃。研究了无机盐(Na2SO4和NaCl)、普通离子型表面活性剂(十六烷基三甲基溴化铵CTAB和十二烷基硫酸钠SDS)和gemini型酯基季铵盐阳离子表面活性剂(Ⅱ-12-6)对苯酚萃取率E的影响。结果表明,盐的加入会使E下降,但Na2SO4对E的影响比NaCl要小;添加SDS使E下降,并随着n(SDS)∶n(AEO9)的增加而下降;而添加CTAB或Ⅱ-12-6均使E明显提高,且随着n(CTAB)∶n(AEO9)、n(Ⅱ-12-6)∶n(AEO9)的增加而进一步提高;但在同等条件下添加Ⅱ-12-6的E高于添加CTAB。     

醇对正负离子表面活性剂双水相性质的影响

The effect of alcohol on the aqueous two-phase system properties of SDS/CTAB/H2O/Na2SO4 system was studied by the pseudo ternary phase diagram. The electrostatic forces (both attraction and repulsion) between cationic surfactant and anionic surfactant decreased because of the interaction of alcohol hydroxyl group and surfactant polar group. As a result, the phase area width of aqueous two-phase system increased. Long chain alcohol (more than five carbonatoms), which was in high concentration in the SDS/CTAB/H2O/Na2SO4) system, caused the anionic aqueous two-phase system area to vanish and the cationic aqueous two-phase system area to become wider. The CTAB rich phase turned from top phase to bottom phase.     

含Gemini成分的正负离子表面活性剂混合体系的双水相

研究了羧酸盐Gemini表面活性剂(C11pPHCNa)与季铵盐普通表面活性剂(DTAB)混合体系的双水相(pH =12)。结果表明,在恒定总浓度cT时改变混合比R,或恒定R改变cT,双水相上下相外观均发生改变,负染色电镜观测证实这是由上下相囊泡尺寸的变化所致。双水相的分相时间曲线出现一最低点,这可能与囊泡本身的性质以及囊泡之间的相互作用有关。     

阴离子表面活性剂与阳离子表面活性剂的相互作用(Ⅲ)——高浓度区溶液性质

综述了阴/阳离子表面活性剂混合溶液在浓度比较高时出现的双水相和囊泡现象,并对这种双水相形成条件和囊泡的稳定性进行了比较详细的讨论。阴/阳离子表面活性剂混合溶液中的双水相现象只能在两个非常狭窄的区域形成,可能由不同浓度的胶束溶液、胶束溶液与液晶相或囊泡等组成。在一定的条件下,比较稳定的囊泡可以自发或经过超声处理形成。     

表面活性剂双水相萃取分离氨基酸研究

用溴化十二烷基三乙铵(C12NE)与十二烷基硫钠(SDS)混合体系形成双水相,测定混合摩尔比与分相比例的关系,并以苯丙氨酸为萃取对象研究其在双水相体系中的分配及多级错流萃取效果。实验结果表明,当C12NE与SDS摩尔比为(1.6∶1)—(1.7∶1)时体系有分相,其中当C12NE与SDS摩尔比为1.65∶1时,分相所得上下相体积比为1∶1,且分相时间为10 m in左右,为适合实验条件。双水相体系萃取苯丙氨酸的结果表明,单级萃取率可达80%以上,二级萃取率可达99%以上。     

青霉素萃取体系中第三相的生成与机理研究

在青霉素／ＣＴＡＢ／水／乙酸丁酯的模拟萃取体系中,当青霉素的浓度为 ０．０４２ｍｏｌ／Ｌ、 ＣＴＡＢ浓度小于 ０．０５４ ｍｏｌ／Ｌ时体系有第三相产生：当ＣＴＡＢ浓度大于０．０５４ ｍｏｌ／Ｌ时第三相消失,体系恢复为两相,此时下相有严重的乳光现象。第三相表面张力、粘度受ＣＴＡＢ和青霉素的浓度变化影响不大,而第三相的电导值受ＣＴＡＢ的浓度影响较大,组分分析证明第三相有大量的水和乙酸丁酯互溶,其中青霉素与ＣＴＡＢ的浓度比接近１：１。第三相通过冷冻蚀刻透射电镜观察,发现比较典型的片层状结构。对第三相的形成原因做了部分解释。     

Effect of Electrolyte and Temperature on Volatile Organic Compounds Removal from Wastewater Using Aqueous Surfactant Two-Phase System of Cationic and Anionic Surfactant Mixtures

Abstract

Benzene, toluene, ethylbenzene, and xylene are frequently observed contaminants in industrial wastewaters causing concerns about environmental and health effects. An aqueous surfactant two-phase (ASTP) extraction system using mixtures of cationic and anionic surfactants have been shown to be a promising surfactant-based separation technique to concentrate solutes such as proteins and dyes from aqueous solution. A phase separation of a surfactant solution occurs at certain surfactant compositions and concentrations, forming two isotropic phases. One is rich in surfactant aggregates (surfactant-rich phase) and the other is lean in surfactant aggregates (surfactant-dilute phase). Most of the organic contaminants tend to solubilize and concentrate in the surfactant-rich phase, leaving the surfactant-dilute phase containing only small amounts of contaminants as remediated water. The effect of NaCl addition on the critical micelle concentration (CMC) and the extraction ability of ASTP formed by mixtures of cationic surfactant (dodecyltrimethylammonium bromide; DTAB) and anionic surfactant (alkyl diphenyloxide disulfonate; DPDS) at 50 mM total surfactant concentration with a 2:1 molar ratio of DTAB:DPDS was investigated; the CMC of the mixture slightly decreases with increasing NaCl concentration. The extraction and preconcentration of benzene are greatly enhanced by added NaCl. The higher the degree of hydrophobicity of contaminants, the greater the extraction into the surfactant-rich phases. At 1.0 M NaCl addition, about 95% of xylene, 92% of ethylbenzene, 90% of toluene, and 79% of benzene are extracted into the surfactant-rich phase within a single stage extraction and the contaminant partition ratios can be as high as 395 for xylene, 273 for ethylbenzene, 206 for toluene, and 84 for benzene, which are greater than those obtained from the conventional ASTP extraction system using nonionic surfactants.     

Stability of high internal phase emulsions with sole cationic surfactant and its tailoring morphology of porous polymers based on the emulsions

Stable w/o high internal phase emulsion (HIPE) using cetyltrimethylammonium bromide (CTAB) as the sole surfactant was prepared with long time further mixing of the emulsion after the addition of aqueous phase was completed, although it was generally considered the emulsion would be unstable according to Bancroft rule. The delta backscattering data of these emulsions showed that the further mixing enhanced the stability of the HIPE significantly, because a dram partial of monomers was initiated in the period of preparing the emulsion, which reduced the diffusion of CTAB from the oil phase to aqueous phase and increased the viscosity of the continuous phase. In addition, the morphology of polyHIPEs based on this type HIPEs was tailored. Increasing aqueous phase fraction resulted in the increase of pore volume which could be up to 24.0 ml/g. Increasing the polymerization temperature led to an increase in average void and interconnect diameter in the resulting porous materials. Additionally, the presence of additives, PEG and ethanol, in the aqueous phase was found to increase the average void diameter remarkably. The interconnect diameter of the materials could be controlled at constant pore volume by tuning PEG and ethanol concentration in the aqueous phase. It was suggested that coalescence was the dominant effect in determining the morphology of the polyHIPEs prepared in the presence of PEG, and Ostwald ripening was the major role in tailoring the morphology of the porous materials with ethanol.     

Kinetic study of the hydrolysis of two formate esters held in a single organic drop

The rising drop technique was used to study the kinetics of the alkaline hydrolysis of two formate esters; n-butylformate and iso-amylformate in toluene formed the organic phase, whilst aqueous sodium hydroxide was used as the continuous phase. The effects of ester and alkali concentrations on the rate of the hydrolysis were studied. The order of the reaction was found to change with respect to the concentration of both reactants. Cetyltrimethylammoniumbromide (CTAB) was used as a possible catalyst for this liquid–liquid hydrolysis. When CTAB was added to the aqueous phase, enhancement of reaction was observed, whilst its addition to the organic phase caused inhibition of the hydrolysis. It is suggested that the enhancement of the reaction is due to the interaction of micelles in proximity to the interface while the inhibition is probably due to chemical blocking of the interface by adsorbed molecules of ionized CTAB.     

Phase behavior of aqueous two-phase systems of cationic and anionic surfactants and their application to theanine extraction

Phase behavior of aqueous two-phase systems (ATPS) containing cationic (SDS) and anionic (CTAB) surfactants and its application to theanine extraction was studied. Results indicated the ATPS could form under the certain SDS/CTAB molar ratio; there was a reasonable consistency between the conductivity and the formation region of ATPS, and the viscosity was higher in the formation region of ATPS. Additionally, the phase ratio increased with increase of CATB concentration, and the interfacial film between the top phase and the bottom phase was resilient. Moreover, the theanine extraction with ATPS was realized in the waste liquid of tea polyphenol production (WLTPP), and the partition coefficient of theanine decreased with increase of WLTPP concentration, whereas the extraction rate of theanine increased. The partition coefficient decreased with increasing SDS/CTAB molar ratio, and the extraction rate of theanine increased with increase of SDS/CTAB molar ratio.