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。     

浊点萃取技术及其在分离过程中的应用

浊点萃取(CPE)技术是一种新型的环境友好的溶质富集和分离方法,其应用领域已经自最初的样品分析扩展到大规模的分离过程如水处理和生物产品提取.与传统的溶剂萃取技术相比,该技术具有快速、高效、简便、无需大量有机溶剂等特点.本文简要介绍了浊点萃取技术机理研究的新进展和近期报道的分离过程中的应用.     

双水相胶束萃取苯酚

根据胶束的加溶原理和非离子表面活性剂系统在浊点温度以上自动分相的现象 ,采用TritonX - 10 0胶束系统萃取苯酚 .结果表明 :苯酚的比胶束加溶量与其在水相的平衡浓度成比例关系 .测定了比例系数 ,即加溶平衡常数 .由此建立了数学模型 ,讨论了表面活性剂浓度、溶质浓度、pH值等因素对萃取率的影响 .模型计算结果和实验结果都说明 ,调节pH值可以反萃取苯酚的原因是苯酚电离改变了加溶平衡常数     

添加剂对非离子表面活性剂浊点的影响

研究了醇类、聚合物、离子型表面活性剂、有机复配物等添加剂对非离子表面活性剂浊点的影响,总结出几类添加剂对非离子表面活性剂浊点的影响规律。结果表明,有机醇对浊点的影响比较复杂,聚合物随着分子链的长短对浊点的影响而不同,离子型表面活性剂的加入会有效提高非离子表面活性剂的浊点。     

浊点萃取技术及其在农药残留分析中的应用

浊点萃取技术是基于表面活性剂溶液相分离现象的一种新兴的液-液萃取技术,已经成功的与多种分析仪器联用,用于农药残留样品的前处理中。介绍了浊点萃取技术的原理和影响因素,重点综述了浊点萃取作为气相色谱、液相色谱、分光光度计、荧光光度计的前处理技术在农药残留分析中的应用进展,探讨了该技术方法的发展前景。     

浊点萃取-火焰原子吸收法测定水中的痕量钴

研究了以DDTC作为配位剂,浊点萃取预富集-火焰原子吸收法应用于水样中痕量的钴测定的实验方法;对实验条件进行了优化,用该方法对水样中的钴含量进行了测定,并对此方法的可靠性和精确性进行了验证。     

十二烷基硫酸钠对非离子表面活性剂CM101浊点的影响

研究了阴离子表面活性剂十二烷基硫酸钠(SDS)对非离子表面活性剂CM101浊点的影响。结果表明:当SDS加入量为2%时,CM101的浊点提高到59.6℃,达到农药制剂热稳定性的要求。同时,该混合体系满足非理想二元表面活性剂复配增效的条件,表面张力和临界胶束浓度都有明显降低。     

浊点萃取-高效液相色谱法测定工业废水中4种苯酚类化合物

建立了浊点萃取法与高效液相色谱联用测定4种苯酚类化合物(对苯二酚、间苯二酚、邻苯二酚和苯酚)的分析方法.以磷酸三丁酯为配合剂,Tergitol 15-S-7为萃取剂,4种目标化合物与磷酸三丁酯通过氢键作用力形成了易于被Tergitol 15-S-7萃取的疏水性配合物,解决了苯酚类化合物萃取率低的问题.实验优化了配合剂、...     

聚醚型非离子表面活性剂的浊点及其影响因素

总结了非离子表面活性剂浓度、外加聚合物、离子表面活性剂、无机电解质、助表面活性剂等对聚醚型非离子表面活性剂水溶液浊点的影响规律 ,发现聚合物由于其结构和分子量不同对浊点的影响也不同 ,一般可使浊点降低 ;加入离子表面活性剂可以和非离子表面活性剂形成混合胶束 ,从而使浊点升高 ;无机盐由于存在盐析和盐溶两种不同效应而对浊点的影响比较复杂 ;醇和有机酸等助表面活性剂根据其碳链的长短不同而影响浊点。这些规律对非离子表面活性剂的研究和应用有一定的指导意义。     

非离子表面活性剂浊点应用研究进展

本文综述了非离子表面活性剂浊点预测的各种模型,阐述了实用配方中添加剂对非离子表面活性剂浊点的影响因素及浊点测定的新方法。     

Mechanism of antifoam behavior of solutions of nonionic surfactants above the cloud point

Aqueous solutions of nonionic surfactants exhibit low foaming above their cloud point, a temperature above which the homogeneous solutions separates into two phases: a dilute phase containing a low surfactant concentration and coacervate phase containing a very high surfactant concentration (e.g., 20 wt% surfactant). In this work, foam formation was measured for the dilute phase, the coacervate, and the mixed solution using the Ross-Miles method for nonylphenol polyethoxylates with 8, 9, or 10 ethylene oxide moieties per molecule. The dilute phase showed no antifoam effect above the cloud point if the coacervate phase was not present, and the coacervate phase foamed little in the absence of the dilute phase. The coacervate phase acts as an oil droplet antifoam to the dilute phase. From surface and interfacial tension data, entering, spreading, and bridging coefficients for this system make it appear probable that the coacervate phase is forming bridges across the film lamellae of the dilute-phase foam and acting to suppress foam formation through the bridging mechanism.     

Microemulsion Extraction of Monascus Pigments from Nonionic Surfactant using High Polarity of Diethyl Ether as Excess Oil Phase

Stripping of organic compound from nonionic surfactant micelle aqueous solution is indispensable for many industrial processes. In this paper, a relatively high polarity diethyl ether was screened for forming Winsor I microemulsion, which was used for stripping of organic compound from nonionic surfactant. Setting up extractive fermentation of Monascus pigments in Triton X-100 aqueous solution as a model, cloud point extraction of Monascus pigments from fermentation broth, and back-extraction of Monascus pigments from the coacervate phase of cloud point system by Winsor I microemulsion were conducted. Monascus pigments were successfully separated from nonionic surfactant into the excess diethyl ether phase.     

Cloud Point Extraction of Nitrobenzene using TX-100

Cloud point extraction (CPE) is carried out to extract nitrobenzene (NB) from aqueous solution using TX-100 as a nonionic surfactant. The effects of different operating parameters, like concentration of the feed mixture (both NB and surfactant), pH, temperature, and the presence of mono- and di-valent salts on the extraction of both the NB and surfactant have been studied in detail. The solubilization behavior of the NB in the surfactant micelle has been observed in the temperature range of 75°C to 90°C. Concentrations of surfactant and NB have been considered in the range of 0.03 M to 0.25 M and 100 mg/L to 400 mg/L, respectively. An optimum set of surfactant concentration, temperature, and salt concentration is obtained for the removal of NB from aqueous medium. The effects of temperature and concentrations of surfactants and NB on various thermodynamic parameters, like change in Gibbs-free energy (ΔG ⁰), change in enthalpy (ΔH ⁰), and change in entropy (ΔS ⁰) are observed and explained well. Experimental investigations have also been carried out for the recovery of the surfactant from the dilute phase applying solvent extraction (SE) in batch condition using heptane and hexane as the extracting medium.     

非离子表面活性剂缔合结构的物理化学性能研究进展

从浊点,表面张力表面吸附、胶束形成热力上行为、与离子表面活性剂的复配,与聚合物的相互作用,微乳液的热力学性质,在非水体系中的物化性能等方面总结了近年来国内外应用现代实验技术对非离子表面活性剂缔合结构物理化学性能的研究现状况,得到了许多有益的规律和结论,并对各个研究领域进行了展望。这地丰富表面活性剂的基础理论和进一步开发利用非离子表面活性剂具有重要意义。     

Cloud Point Extraction of Orange II and Orange G Using Neutral and Mixed Micelles: Comparative Approach Using Experimental Design

The aim of this work was to compare two synthetic dyes, Orange G (7-Hydroxy-8-(phenylazo)-1,3-naphthalenedisulfonic acid, disodium salt) and Orange II (p-(2-Hydroxy-1-naphthylazo) benzenesulfonic acid, sodium salt), towards cloud point extraction from colored water. Three commercial non-ionic surfactants were used in this work: Oxo-C₁₅E₇, Oxo-C₁₀E₃, and Triton X-100. The experimental extraction results were expressed by the following three responses: percentage of the extracted dye (E), residual concentrations of dye in the dilute phase (X_s,w), and the volume fraction of coacervate (?_C) at the equilibrium. The results obtained for each parameter were represented on three dimensional diagrams using an empirical smoothing method. In optimal conditions Orange II concentration in the effluent was reduced to about 227 times, whereas E did not exceed 55% using Oxo-C₁₅E₇ in the case of Orange G extraction. However, when a small amount (0.025 wt.%) of cetyltrimethylammonium bromide (CTAB) was combined with Oxo-C₁₀E₃ as a mixed micelles system, the results showed that the extraction percentage of Orange G increased from 55 to 98%. Indeed, the concentration of this dye in the effluent was reduced to about 400 times. Finally, the extraction extent of both dyes was found to be low at basic pH, which may be useful for surfactant regeneration.