非离子表面活性剂C12E10的浊点分相行为及其应用

引言 络合萃取技术对极性有机物稀溶液和金属离子的分离具有高效性和高选择性,已广泛应用于湿法冶金领域.由于萃取剂在萃残液中分子水平的溶解以及萃取塔器操作时水相对于萃取剂相细小液滴的夹带,造成了一定程度的萃取剂流失和环境污染,同时,由于萃取剂大都分子量较大,生物降解性能不佳[1],因此,开展从水溶液中回收萃取剂的研究是十分必要的.     

Nonionic surfactants induced cloud point extraction of Polyhydroxyalkanoate from Cupriavidus necator

Polyhydroxyalkanoate synthesized by Cupriavidus necator DSM 428 was purified from the crude fermentation broth as such by performing nonionic surfactants (Triton X100, Triton X114 & Tergitol 6) induced cloud point extraction. Polyhydroxyalkanoate was extracted into the micelle-rich bottom phase (coacervate phase), while most of the cellular impurities partitioned into the aqueous phase. Cloud point temperatures and the extraction efficiency of different cloud point systems were studied at different pH value and in the presence of additives. Maximum extraction of biopolymer was achieved (recovery of 84.4%) with a purity of 92.49% at 3 pH with the addition of 0.1 M ammonium chloride in the mixed surfactant system at a reduced cloud point temperature of 33°C.     

Aqueous Surfactant Two‐Phase Systems for the Continuous Countercurrent Cloud Point Extraction

Aqueous nonionic surfactant solutions split into two phases if the temperature is increased beyond a certain temperature, the so‐called cloud point temperature. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction. In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. Phase equilibria of the binary system Triton X‐114/water and the ternary system Triton X‐114/water/phenol were measured. Based on these data the cloud point extraction was implemented in a continuous stirred extraction column. It was found, that increasing temperature within the column reduces the loss of surfactant and leads to an increasing enrichment factor. This work demonstrates that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in continuous extraction columns.     

浊点萃取-FAAS法测定化妆品中六价铬

提出了浊点萃取-火焰原子吸收光谱法测定化妆品中痕量六价铬的方法。考察了溶液pH、APDC用量、Triton X-114用量、平衡温度及时间等条件对浊点萃取率的影响,在优化条件下,对化妆品进行测定。该方法测定铬的检出限为0.026 mg/L,相对标准偏差为1.52%。结果表明：市售多数化妆品中的铬含量超过国家标准,须引起质量监督部门的注意。     

浊点萃取-火焰原子吸收光谱法测定乙醛触媒微量钯含量

建立了以1-（2-吡啶偶氮）-2-萘（PAN）为络合剂,以非离子表面活性剂TritonX-100为萃取剂的浊点萃取分离富集-火焰原子吸收光谱法测定痕量钯的新方法。研究了溶液的酸度、络合剂和表面活性剂浓度、平衡温度和时间、离子强度等条件对浊点萃取效果的影响。该方法对钯的检出限为35．3ng／mL,相对标准偏差（RSD）为3．1％（n=8）,回收率97．6％0～106．7％。可用于乙醛催化剂中微量Pd（Ⅱ）的测定。     

Cloud Point Extraction of Four Triphenylmethane Dyes by Triton X-114 as Nonionic Surfactant

A method for removing four triphenylmethane dyes from wastewater by cloud point extraction with the nonionic surfactant Triton X-114 (TX-114) was developed. The triphenylmethane dyes were crystal violet, ethyl violet, malachite green and brilliant green. The cloud point of TX-114 generally increased in the presence of any of the four dyes. In the cloud point system, these dyes were solubilized into a coacervate phase that left a color-free dilute phase. The extraction efficiency of the dyes increased with the temperature, TX-114 concentration, and salt (NaCl and CaCl₂) concentration. More than 97% TX-114 in the dilute phase was recovered by adjusting the volume ratio of dichloromethane to the dilute phase. The Langmuir-type adsorption isotherm was used to describe the dye solubilization. The Langmuir constants m and n were calculated as functions of temperature. The results showed that the solubilization of the triphenylmethane dyes in the cloud point system was related to the partition coefficient and their molecular structures.     

Recovery of Saponins from Jua (Ziziphus joazeiro) by Micellar Extraction and Cloud Point Preconcentration

Juá (Ziziphus joazeiro) is a Brazilian plant and its bark has been used as a detergent and phytotherapic due to its high saponin content (2–10 %). Saponins are triterpenic glycosides with some properties that aid their use in food, cosmetic and pharmaceutical industries. The object of the present work was to develop an extraction and concentration process of saponins from jua bark, using green solvents such as water and ethanol. Firstly, the extraction conditions optimization was carried out using a central composite design, and compared with other methods such as Soxhlet, ultrasound-assisted extraction and micellar extraction. Then, cloud point preconcentration was tested to select the salt type and its concentration which promotes a higher concentration factor and partition coefficient at room temperature. Finally, the removal of a t-octyl phenol ethoxylate (9–10 EO) nonionic surfactant by adsorption was evaluated by optimizing the adsorbent type and its concentration, temperature and time of adsorption, in addition to the adsorbent recycling. Orbital shaker extraction leads to a recovery of 45.6 % saponins under the following conditions: temperature, 38.8 °C; jua/solvent ratio, 0.272; stirring speed, 300 rpm; extraction time, 2 h. Under these conditions, saponins recovery reached 90.8 % when using 15 % v/v of the nonionic surfactant, and a preconcentration factor of 14.2 was obtained by adding sodium carbonate 20 % w/v. The preconcentration factor decreased to a value of 10.1, after nonionic surfactant removal by a hydrophobic crosslinked polystyrene copolymer resin.     

非离子表面活性剂TX114浊点萃取D2EHPA的规律

引言浊点萃取[1-2]是利用表面活性剂水溶液的增溶和分相行为实现溶质富集的分离技术。由于分相后表面活性剂的富集相(亦称凝聚相)与水相的体积比非常小(0.007～0.04)[3],所以,对于被增溶的物质能够提供非常高的富集倍数和萃取效率。目前浊点萃取技术主要广泛应用于痕量有害物质     

Cloud Point Extraction and Separation of Scandium and Yttrium (III) with Triton X‐114 in the Presence or Absence 8‐Hydroquiloline as an Added Chelate

Abstract

In this paper, the cloud point extraction and separation of scandium and yttrium (III) via use of Triton X‐114 with and without 8‐hydroquiloline (HQ) as an added chelate agent are investigated. The effects of various parameters, such as the aqueous phase pH, HQ concentration, Triton X‐114 concentration, heating temperature, and incubation time, on the cloud point extraction of scandium and yttrium (III) are studied. The results demonstrate that, there are different extraction and separation behaviors for scandium and yttrium (III) with and without HQ as an added chelate. And in contrast to solvent extraction, cloud point extraction is an excellent method to extract and separate scandium and yttrium (III).     

Thermodynamic analysis of phase separation in an epoxy/polystyrene mixture

The phase separation process of an epoxy prepolymer based on diglycidyl ether of bisphenol A (DGEBA) with a thermoplastic polystyrene (PS) was thermodynamically studied in the frame of the Flory-Huggins theory. The thermodynamic treatment was carried out in two steps: first analysing the phase separation in cloud point conditions, and second analysing the advance of the phase separation for two compositions of 2 and 10% in volume of PS. The effect of the polydispersity of thermoplastic on phase separation was also studied. The polydispersity of PS produces a displacement of the threshold temperature to lower thermoplastic volume fraction (between 2 and 3%) and higher temperature value and the fact that the shadow curve and coexistence curves do not superimpose with the cloud point curve. Theoretical calculations of molecular weight distributions of PS at different degrees of phase separation were realized and different average molecular properties were obtained in each separated phase.     

Partitioning equilibria in multicomponent surfactant systems for design of surfactant-based extraction processes

Aqueous biphasic systems based on nonionic surfactants have perspective applications in extraction processes, in particular, cloud point extraction of hazardous compounds or high valued products, especially biomolecules. Additives (e.g., ionic surfactants, salts) and variations in pH can significantly affect the surfactant-based separation processes, representing an additional degree of freedom for their optimization. However, there are few systematic studies of phase and partition behavior for these multicomponent surfactant systems.In this study we examined the clouding, phase compositions and partitioning equilibria for aqueous mixed surfactant systems of a nonionic surfactant (Triton X-114), ionic surfactants (cetyltrimethylammonium bromide or sodium dodecyl sulfate) and NaCl, in order to improve the extraction efficiency. Vanillin was used as a model substance at three different pH values, specifically in (partly) dissociated or non-dissociated states. The partition coefficients obtained in the batch experiments were compared to the predictions by the thermodynamic model COSMO-RS. Based on this knowledge a continuous multistep extraction process was carried out.To the best of our knowledge this is the first demonstration of using a mixed surfactant system for continuous countercurrent cloud point extraction.     

浊点萃取分光光度法测定水样中痕量铁

建立了浊点萃取-分光光度法测定痕量铁的新方法。详细考察了溶液的pH值、螯合剂和表面活性剂浓度、平衡温度和时间等条件对浊点萃取效果的影响。该方法的线性范围为6.0~500μg/L(r=0.9996),检出限为1.58μg/L,加标回收率为98.7%~101.6%,相对标准偏差为1.3%~2.2%。该方法已成功应用于实际水样分析。     

Micelle-Mediated Extraction and Cloud Point Preconcentration of Chlorophylls from Spinach

A micelle-mediated extraction and cloud point preconcentration of chlorophylls method was developed. Non-ionic surfactant (Genapol X-080) was employed as an alternative and effective extraction solvent. The optimal extraction parameters based on the micelle extraction technique were determined. Under optimal conditions, i.e., 5% Genapol X-080 (v/v), pH 9.0, liquid/solid ratio of 10:1 (mL g^?1), ultrasonic-assisted extraction for 30 min, extraction amount reached the highest value. For the preconcentration of chlorophylls by cloud point extraction (CPE), the solution was incubated at 50° for 30 min, and 0.1 g mL^?1 sodium chloride was added to the solution to facilitate the phase separation. The microstructure of coacervate phase after CPE was explored with transmitting electron microscopy. The preconcentration factor for chlorophylls was about 12.5, the extraction recovery approached 99.2%, and the loading capacity was about 1 mg mL^?1. Thus coupling of ultrasonic-assisted micelle extraction and cloud point extraction could be employed as a new and effective technique for the rapid extraction and preconcentration of chlorophylls from plants such as spinach.     

Extraction of Parabens from Water Samples Using Cloud Point Extraction with a Non-Ionic Surfactant with β-Cyclodextrin as Modifier

A cloud point extraction process using a silicone non-ionic surfactant to extract selected parabens compounds from water samples was investigated using reversed phase high performance liquid chromatography. The cloud point extraction process, in the presence of β-cyclodextrin (β-CD) as a modifier, is a new extraction process which was optimized with five parameters, i.e. salt concentration, pH of the solution, temperature, surfactant concentration and β-CD concentration. The developed method with the β-CD modifier results in an excellent performance on detection of parabens from water samples with limits of detection in the range of 0.017–0.043 μg/L and percentage recoveries from 90.5 to 98.9 %.     

非离子表面活性剂为溶媒的浊点萃取技术

非离子表面活性剂溶液在温度高于其浊点或有一定添加物存在时,会自动形成表面活性剂浓度很小的稀相和表面活性剂浓度很高的凝聚层相,存在于这一系统的溶质将不均匀地分配于二相。文章结合研究成果,综述了这一新型浊点萃取技术的基本理论和应用,同时也介绍了浊点萃取在微生物转化中的新应用。     

Synthetic organofluoromica/poly(lactic acid) nanocomposites: Structure,rheological and thermal properties

Organically modified fluoromica/poly(lactic acid) (PLA) nanocomposites were prepared by melt processing at different compositions in an internal mixer at the same conditions. Gel permeation chromatography (GPC) was used to measure the molar masses of PLA alone, before and after processing. The results indicated that PLA presented some degradation during melt mixing. With the addition of the organically-modified fluoromica, higher reduction in the polymer molar masses was found. The structure of the synthetic mica and of the clay polymer nanocomposites (CPN) was studied by small-angle X-ray scattering (SAXS), which revealed the presence of nanometer-sized clay mineral aggregates. Dynamical rheological measurements were carried out in the linear viscoelastic region for both PLA and CPN molten samples. A predominantly viscous behavior was obtained for the polymer samples, whereas the CPN presented a pronounced elastic behavior. Addition of mica to PLA also had a significant effect on the complex viscosity of PLA, imparting an increasing shear thinning behavior with increasing mica composition. Below T_g, dynamical mechanical analysis results showed a substantial decrease of rigidity of the CPN in relation to PLA alone, attributed to the presence of high content of organic intercalant in the synthetic fluoromica. Lower cold crystallization rate was detected for the CPN in comparison with processed PLA alone.     

非离子型表面活性剂的双水相性质及萃取作用

引　言双水相萃取技术是近年来发展很快的一种生物分离方法[1,2 ] .由于系统中分层的两相都是水相 ,所以该系统为物质的分离特别是生物活性物质的分离提供了温和的环境 .在免疫分析、生物转化等方面也具有良好的应用前景[3] .以往对双水相系统的开发利用基本上仅局限于高分子系     

三坐标检测技术在金属波纹管膨胀节型式试验中的应用

波纹变形量是膨胀节型式试验合格判定的重要参数。针对波纹变形量检测,使用了基于三坐标技术的检测方法。利用三坐标设备对金属波纹管膨胀节进行特征提取和点云采集。利用三坐标软件的分析比较功能,对波纹管特征数据和点云数据进行分析,并将检测的结果以图文方式直观显示出来。该方法的应用为波纹管膨胀节波纹变形量检测提供了方便、快捷、准确的技术手段。     

Synthesis, characterization and physicochemical properties of oleic acid ether derivatives as biolubricant basestocks

Petroleum is a finite source as well as causing several environmental problems. Therefore petroleum needs to be replaced by alternative and sustainable sources. Plant oils and oleochemicals derived from them represent such alternative sources; the use of oleochemicals as biobased lubricants is of significant interest. This article presents a series of chemical modification on oleic acid to yield synthetic biolubricant basestocks. Measuring of density, volatility, cloud point (CP), pour point (PP), flash point (FP), viscosity index (VI), onset temperature (OT) and signal maximum temperature (SMT) was carried out for each compound. Furthermore, the friction and wear properties were measured using high-frequency reciprocating rig (HFRR). The results showed that octadecyl 9-octadecyloxy-10-hydroxyoctadecanoate exhibited the most favorable low-temperature performance (CP %ndash;26°C, PP %ndash;28°C) and the lowest ball wear scan diameter (42 μm) while propyl 9-propyloxy-10-hydroxyoctadecanoate exhibited the higher oxidation stability (OT 156°C).     

Removal of Copper(II) from a Concentrated Sulphate Medium by Cloud Point Extraction Using an N,N′-Bis(salicylaldehyde)Ethylenediimine Di-Schiff Base Chelating Ligand

Various chelating ligands have been investigated for the cloud point extraction of several metal ions. However, limited studies on the use of the Schiff base ligands have been reported. In this work, cloud point extraction behavior of copper(II) with N,N′‐bis(salicylaldehyde)Ethylenediimine Schiff base chelating ligand, (H₂SALEN), was investigated in aqueous concentrated sulphate medium. The extraction process used is based on the formation of hydrophobic H₂SALEN–copper(II) complexes that are solubilized in the micellar phase of a non‐ionic surfactant, i.e. ethoxylated (9.5EO) tert‐butylphenol. The copper(II) complexes are then extracted into the surfactant‐rich phase above cloud point temperature. Different parameters affecting the extraction process of Cu(II), such as equilibrium pH, extractant concentration, and non‐ionic surfactant concentration were explored. The extraction of Cu(II) was studied in the pH range of 2–11. The results obtained showed that it was profoundly influenced by the pH of the aqueous medium. The concentration factor, C_f, of about 17 with extraction efficiency of E % ≈100 was achieved. The stoichiometry of the extracted complex of copper(II) was ascertained by the Yoe–Jones method to give a composition of 1:1 (Cu:H₂L). The optimum conditions of the extraction‐removal have been established as the following: (1) 1.86 × 10^?3 mol/L ligand; (2) 3 wt% surfactant; (3) pH of 8 (4) 0.5 mol/L Na₂SO₄ and (5) temperature of 60 °C.