表面活性剂对液膜分离传质性能的影响

研究了不同表面活性剂组成的液膜体系在分离过程中的传质、溶胀和渗透等性能，分别考查了聚胺型表面活性剂L-113A和LMA-1及酯型表面活性剂Span80对含P204载体液膜体系迁移镧(Ⅲ)的影响，以及L—113A、L—113B和EM-301对无载体液膜体系富集氨氮的影响．实验表明，因表面活性剂不同，造成乳状液膜体系在分离富集镧或氨氮时，分离传质性能相差较大，LMA—1—P204-煤油的液膜体系对镧具有最大的迁移能力。迁移率97．4％；而L-113A-膜相添加剂-煤油的液膜体系对氨氮的溶解渗透能力最大。迁移率为86．4％．另外，对因表面活性剂结构不同而造成油水界面黏度的差异以及对传质速率的影响，从乳状液膜和自组装双分子液膜等方面进行了探讨．     

表面活性剂对液膜法提取柠檬酸影响的研究

表面活性剂种类和浓度对液膜法提取柠檬酸的提取率和乳液溶胀都有一定影响 .在给定条件下 ,提取率随表面活性剂浓度的增大而提高 ,由LMA -1所制成的液膜对柠檬酸的提取率比Span -80高 ,且产生的乳液溶胀也比较小     

液膜用高分子表面活性剂性能研究

本文介绍液膜用高分子表面活性剂PSN_(-89414)的性能,通过界面张力测定,用表面活性剂分子在界面上吸附理论导出公式求得Span80,PS_(-89414)的界面吸附平衡常数K_(?)及S_(af)的数值,结果表明,K_(?)、S_(af)数值愈大的表面活性剂制得乳状液愈稳定,液膜溶胀愈小。PSN_(-89414)的W/O/W乳状液体系用于稀土分离,速度快,从浓度1.2g/L的稀土溶液浓集到103g/L。     

液膜用高分子表面活性剂性能研究

本文介绍液膜用高分子表面活性剂PSN_(-89414)的性能,通过界面张力测定,用表面活性剂分子在界面上吸附理论导出公式求得Span80,PSN_(-89414)的界面吸附平衡常数K_(s)及S_(sf)的数值,结果表明,K_(s)、S_(sf)数值愈大的表面活性剂制得乳状液愈稳定,液膜溶胀愈小。PSN_(-89414)的W/O/W乳状液体系用于稀土分离,速度快,从浓度1.2g/L的稀土溶液浓集到103g/L。     

用TOA为流动载体的乳状液膜提取对氨基苯磺酸

研究了以三辛胺(TOA)为流动载体的乳状液膜法提取对氨基苯磺酸(PASA)的最优膜配方及工艺条件.结果表明:以3%聚胺型表面活性剂(质量分数),4%TOA(体积分数),10%NaOH(质量分数),油内比Roi为2∶1的乳状液膜体系,处理初始浓度为5 000 mg/LPASA废水,在pH值为3,乳水比Rew为1∶5的传质条件下,提取率可达90%以上.     

乳状液膜夹带溶胀的研究

采用界面张力法和聚结电压法测定三种表面活性剂界面张力的时间效应、界面膜的聚结电压以及表面活性剂液膜体系的夹带溶胀率。实验表明,吸附速度慢、聚结电压低的表面活性剂,其夹带溶胀小,因此,认为抑制液膜溶胀的合适表面活性剂是一种吸附速度慢、聚结电压低的聚合物。     

界面聚合中单体结构对复合支撑液膜稳定性的影响

以界面聚合法在支撑液膜的支撑体基膜表面形成一层亲水层,研究了界面聚合改性过程及水相单体结构对复合支撑液膜渗透性和稳定性的影响,以膜表面zeta电位、接触角、透油速率和液膜萃取过程传质通量衰减率对复合膜性能加以表征。结果显示,界面聚合时先浸水相再浸油相,膜表面的荷负电性强,有利于金属阳离子(以Ni(Ⅱ)为代表)的传输。支撑液膜萃取镍(Ⅱ)结果显示,原膜传质通量在30h内由358.2mg/(m2·h)降为0,而赖氨酸分子因具有强亲水基团羧基且脂肪链的引入会增加聚合物大分子的柔曲度,以其制备的复合液膜支撑体表面具有较好的亲水性,对液膜相的锁闭能力较强,Ni(Ⅱ)的传质通量在30h内仅衰减28.3%,有利于增强支撑液膜在长期运行中的稳定性。     

N263为载体的乳状液膜稳定性的研究

针对Ｎ２６３为载体的乳状液膜稳定性问题，研究了单一表面活性剂、混合表面活性剂、载体、膜相添加剂、外水相酸度及实验操作温度因素对液膜稳定性的影响。并探讨了表面活性剂Ｂ值与液膜稳定 之间的关系，从而得出一些影响乳状液膜稳定性规律的有效结论。     

液膜处理过程中粘度的变化

研究了影响多重乳状液粘度的一些因素,如表面活性剂、添加剂、油内比、搅拌速度、内相试剂及其浓度、温度等。并对多重乳状液的粘度和溶胀规律作了考察,发现乳状液的粘度与液膜的稳定性和溶胀密切相关。     

液膜处理过程中粘度的变化

研究了影响多重乳状液粘度的一些因素,如表面活性剂、添加剂、油内比、搅拌速度、内相试剂及其浓度、温度等。并对多重乳状液的粘度和溶胀规律作了考察,发现乳状液的粘度与液膜的稳定性和溶胀密切相关。     

Effects of mixed surfactants on the volatilization of naphthalene from aqueous solutions

The effects of mixed anionic-nonionic surfactants, Tween40-SDS (sodium dodecyl sulfate), Tween40-SDBS (sodium dodecylbenzene sulfonate), Tween20-SDS and Tween20-SDBS, on the solubility and volatilization of naphthalene from static aqueous solutions were investigated. The experiment results indicated that mixed anionic-nonionic surfactants can solubilize naphthalene synergistically, which was resulted from the reduction in critical micelle concentration (CMC) of the mixed surfactant and the increase in micellar partition coefficient (K(mc)) of naphthalene between micelles and aqueous phase. The synergistic effects of mixed surfactants resulted in further reduction in volatilization of naphthalene than that induced by single surfactant. A positive linear correlation was found between the synergistic solubilization ratio (DeltaS) and the synergistic inhibitory capacity on naphthalene volatilization (DeltaC) in the presence of mixed surfactants. Results from this study imply that mixed surfactants can be employed in environmental remediation to formulate the needed solubility and volatilization of volatile and semivolatile compounds in aqueous solutions.     

Concentration of hydrophobic organic compounds and extraction of protein using alkylammoniosulfate zwitterionic surfactant mediated phase separations (cloud point extractions).

The zwitterionic surfactants 3-[nonyl- (or decyl-) dimethyl-ammonio]propyl sulfate, (C9-APSO4 or C10-APSO4) were synthesized using Nilsson's procedure, and their phase separation behavior under different experimental conditions was evaluated. The results indicate that such zwitterionic surfactants can be utilized for the extraction/preconcentration of hydro-phobic species in a manner akin to that previously reported for nonionic surfactants. This was demonstrated for several practical applications including the extraction/preconcentration of some steroidal hormones and vitamin E prior to high-performance liquid chromatography analysis. The zwitterionic surfactant mediated phase separation was also applied to the extraction of the hydrophobic membrane protein, bacterio-rhodopsin, from the hydrophilic cytochrome c protein, both originally present in an aqueous phase. The concentration factors for this aqueous two-phase extraction technique using C10-APSO4 ranged from 26 to 35 with recoveries in the range 88 to greater than 96%. Some comparative studies indicate that the use of zwitterionic surfactants in lieu of nonionic surfactants (e.g. polyoxyethylene(7.5) nonyl phenyl ether PONPE-7.5) in such an extraction method offers some significant advantages such as purer, homogeneous surfactant preparation, minimum background absorbance at UV detection wavelengths, the two-phase region occurring at lower temperatures, and greater extraction efficiencies/concentration factors among others.     

Solute-solvent interactions in micellar electrokinetic chromatography. 6. Optimization of the selectivity of lithium dodecyl sulfate-lithium perfluorooctanesulfonate mixed micellar buffers

The optimization of the composition of mixed surfactants used as micellar electrokinetic chromatography (MEKC) pseudostationary phases is proposed as an effective method for the separation of complex mixtures of analytes. The solvation parameter model is used to select two surfactants (lithium dodecyl sulfate, LDS, and lithium perfluorooctanesulfonate, LPFOS) with contrasting solvation properties. Combination of these two surfactants allows variations of the solvation properties of MEKC pseudostationary phase along a wide range. Thus, the convenient variation of the proportion of both surfactants allows an effective control of the selectivity in such systems. An algorithm that predicts the overall resolution of a given mixture of compounds is described and applied to optimize the composition of the mixed surfactant for the separation of the mixture. The algorithm is based on the calculation of peak purities on simulated chromatograms as a function of the composition of the mixed LDS/LPFOS micellar buffer from data at several micellar buffer compositions. Successful separations were achieved for mixtures containing up to 20 compounds, in less than 12 min.     

Study of mixed micelles and interaction parameters for polymeric nonionic and normal surfactants

Surface tension (ST) measurements were carried out on various binary mixtures of the "normal" surfactants, such as nonionic surfactant, hexaethylene glycol mono-n-dodecyl ether(C12EO6), and cationic surfactant, tetradecyltrimethylammonium bromide (TTAB), and polymeric copolymer, Pluronic F127, F127(PPO)-g-PVP, and F127(PEO)-g-PVP. In all cases mixed micellar aggregates were formed and critical micellar concentrations of binary mixtures containing different mole fractions of the surfactants were measured using surface tension measurement. In the region where mixed micelles are formed, the interaction of two "normal" surfactants and three "polymeric" nonionic surfactants showed synergistic behavior and the results were analyzed using a interaction parameter, beta, which characterized the interaction in the mixed micelle and introduced by a regular solution theory. The regular solution theory can be applied to describe the interaction between TTAB and C12EO6, and graft polymeric surfactants systems. The results discussed in this paper indicated that regular solution theory has broader extent of application.     

Geotechnical properties of some organoclays

The engineering characteristics of clay are dependant on its mineral and chemical structure. When the clay soils interacted with water, their volume and shear strength and compressibility properties change gradually. Large amount of decrease in terms of the shear strength of clay soils due to swelling is observed. In order to solve these problems, the stabilization of clay soils using chemical additives is a prevalent subject of research. In view of this, previous research studies have employed surface active surfactants to modify the fundamental properties of soft clays. In this study, surfactant–clay complexes (organoclays) were developed using a raw clay modification with four surfactants and their geotechnical properties were determined in laboratory conditions. Two of the surfactants are cationic (cetyl trimethyl ammonium chloride, denoted as CTAC and quaternised ethoxylated fatty amine, denoted as QEFA) and the others are anionic (linear alkylbenzene sulphonic acid, denoted as LABSA and sodium lauryl ether sulfate, denoted as SLES). The experimental results indicated that the geotechnical properties of organoclays show significant change when compared to those of natural clay. The specific gravities, unconfined compression strengths and maximum dry densities of all organoclays were decreased. Optimum moisture content and swelling pressure values were decreased in cationic surfactant modified clays. However, the optimum moisture content and swelling pressure values of anionic surfactant clays are increased. A direct shear test was performed to determine the shear strength of organoclays. The test results also showed that the internal friction angles of organoclays were increased. Additionally, the change in the hydraulic conductivity was found to be insignificant.     

Optimal selection of viscoelastic surfactant fracturing fluids based on influence on coal seam pores

Coalbed methane is stored mainly in coal pores, and pore changes by fracturing fluid affect the extraction effect of coalbed methane. To select the optimal formulation of viscoelastic surfactant (VES) fracturing fluids, we treated coal samples of different hardness with deionized water (A) and three different fluids that contained cationic surfactants (B), mixed cationic and zwitterionic surfactants (C) and mixed anionic and zwitterionic surfactants (D) as the main agents. The effect of the three VES fracturing fluids on pores was compared quantitatively and on a multi-scale. The pore characteristics were tested by field emission-scanning electron microscopy, mercury intrusion capillary pressure and low-pressure nitrogen physisorption. Image-Pro Plus 6.0 software was used to digitize information from the obtained images. The Angulo and Frenkel–Halsey–Hill models were used to calculate the fractal dimension by using mercury intrusion capillary pressure and low-pressure nitrogen physisorption data, respectively. The effect of VES fracturing fluids B and D on pores from 14 nm to 180 μm was greater than that for VES fracturing fluid C as the main agent. The effect of VES fracturing fluid C on the pores (2–300 nm) was most obvious.     

Solubilization of pyrene by anionic-nonionic mixed surfactants

Surfactant-enhanced remediation (SER) is an effective approach for the removal of sorbed hydrophobic organic compounds from contaminated soils. The solubilization of pyrene by four anionic-nonionic mixed surfactants, sodium dodecyl sulfate (SDS) with Triton X-405 (TX405), Brij35, Brij58, and Triton X-100 (TX100), has been studied from measurements of the molar solubilization ratio (MSR), the micelle-water partition coefficient (Kmc), and the critical micelle concentration (CMC). The MSRs of pyrene in mixed surfactants are found to be larger than those predicted according to an ideal mixing rule. The mixing effect of anionic and nonionic surfactants on MSR for pyrene follows the order of SDS-TX405 > SDS-Brij35 > SDS-Brij58 > SDS-TX100 and increases with an increase in the hydrophile-lipophile balance (HLB) value of nonionic surfactant in mixed systems. In addition, the mixture of anionic and nonionic surfactants cause the Kmc value for pyrene to be greater than the ideal value in SDS-TX405 mixed system, but to be smaller than the ideal value in SDS-Brij35, SDS-Brij58, and SDS-TX100 mixed systems. Meanwhile, in the four mixed systems, the experimental CMCs are lower than the ideal CMCs at almost all mixed surfactant solution compositions. The mixing effect of anionic and nonionic surfactants on MSR for pyrene can be attributed to the conjunct or the net result of the negative deviation of the CMCs from ideal mixture and the increasing or decreasing Kmc.     

乳状液膜法提取青霉素G的研究

使用青霉素Ｇ钠盐纯品溶液,模拟考察了乳状液膜法分离青霉素的条件．着重研究了提取率与膜中载体类型、Ｓｐａｎ－８０用量的关系,优化出最佳提取条件,在最佳条件下青霉素的提取率可达９２％,浓缩比可达９．     

Extraction of Co(II) from aqueous solution using emulsion liquid membrane

The extraction equilibrium of Co(II) from thiocyanate medium by CYANEX 923 (mixture of straight chain alkylated phosphine oxides) in cyclohexane was studied. The stoichiometry of the extraction reaction was postulated based on slope analysis method and the extraction constant Kex was calculated. The stripping percentage of Co(II) with sulphuric acid from the loaded CYANEX 923 was found to increase with the increase in acid concentration. The extraction of Co(II) from aqueous thiocyanate medium into emulsion liquid membrane using CYANEX 923 extractant was also studied. The influence of different parameters such as stirring speed, surfactant concentration, pH of the extractant phase, carrier concentration, internal phase stripping acid concentration, initial Co(II) concentration as well as temperature on the emulsion stability were investigated. The applicability of the emulsion liquid membrane (ELM) process using CYANEX 923 as extractant and SPAN 80 as surfactant for the removal and the concentration of Co(II) from thiocyanate solution was investigated. The results show that it is possible to recover 95% of cobalt in the inner phase after 10 min of contacting time with a concentration factor of 5.     

Investigation on the solubilization of polycyclic aromatic hydrocarbons in the presence of single and mixed Gemini surfactants

Water solubility enhancements of naphthalene (Naph), phenanthrene (Phen) and pyrene (Py) by a series of single cationic Gemini surfactants (CG(s), s=4, 8, 12 and 16) as well as their equimolar binary combinations (CG(12-m), m=4, 8 and 16) have been investigated. The relationships between their surface properties and solubilizing capacities toward three polycyclic aromatic hydrocarbons (PAHs) have been quantified and discussed. The selected single Gemini surfactants observably enhance the water solubility of PAHs following the order of Phen>Py>Naph except for CG(8) which has a superior solubilizing ability for Py. For the same organic compound, the solubilizing abilities of single Gemini surfactants are in tune with the order of variation tendencies of CMC values. However, the different mixed Gemini surfactant systems have shown selective solubilization on various PAHs which is not simply related to their mixed molar properties. Particularly, the CG(12-16) surfactant has relatively comparable solubilization on Py and inferior solubilization on Phen compared to all other investigated solubilizing systems. It is presumably attributed to the relationships between the structure of surfactants and the chemical nature of both solutes and surfactants. The analysis studied herein has provided valuable information for the selection of mixed Gemini surfactants for solubilizing water-insoluble compounds.