用微胶囊萃取铀

用微胶囊萃取铀倪沛红张明祖陈漫里严年喜（苏州大学化学化工学院，苏州２１５００６）关键词微胶囊萃取铀界面缩聚平均粒径１前言铀作为核燃料之一具有重要的应用价值。有关铀的提取方法已经研究得很多，主要是采用溶剂萃取的方法。八十年代以来，有关液膜法萃取铀的研究...     

煤的溶剂热萃取研究进展

综述了近年来在煤的溶剂热萃取（不小于300℃）的研究进展。讨论了主要影响因素包括极性溶剂、酸处理、萃取时间等对热萃取率的影响。结论表明：酸处理、使用强极性溶剂有利于提高煤的热萃取产率;时间和温度是热萃取的两个重要参数,在不同程度上影响着煤的热萃取率;萃取物活性很高,并且基本无灰,是煤直接液化的极好的原料也可以作为内燃机燃料。     

溶剂蒸发法制备药物微胶囊研究进展

介绍了溶剂蒸发法制备微胶囊的原理,分析了溶剂蒸发法制备药物微胶囊的工艺的研究现状。重点讨论了以下3个主要方面：（1）微液滴的形成;（2）溶剂蒸发法制备微胶囊;（3）微胶囊颗粒的回收和干燥,并对溶剂蒸发法制备微胶囊技术的发展作了展望。     

溶剂蒸发法液晶微胶囊表面形貌研究

本文首次报道一种具有特殊形貌的液晶微胶囊,胶囊表面部分区域光滑致密,其余区域粗糙且存在孔隙。文章基于相分离机理对微胶囊形成过程进行分析,并通过加入共溶剂实现了微胶囊表面形貌的可控调整。     

萃取精馏溶剂选择的研究进展

本文概括论述了萃取精馏过程中影响溶剂选择的因素，在此基础上着重介绍了溶剂的选择方法，性质约束方法可分为：试验法，经验筛选和活度系数法；计算机优化方法可分为计算机辅助分子设计法和人工神经网络法，对上述方法的适用性作了详细的讨论。     

不同溶剂神府煤超临界萃取研究

本文以我国新开发的特大煤田——神府煤为研究对象,在半连续装置上,以水、甲苯以及水和甲苯中分别加入少量四氢萘为溶剂进行超临界萃取研究。详细地考察了无机溶剂水、有机溶剂甲苯及供氢溶剂四氢萘对萃取过程的影响。实验结果表明,超临界萃取是神府煤的有效利用途径之一,萃取物产率是铝甑焦油产率的2.65～5.72倍,萃取物中以预沥青烯为主要族组分;以甲笨为溶剂,萃取率高于以水为溶剂的;在水及甲苯中加入少量四氢萘,均可以大幅度地提高萃取率。     

溶剂挥发法制备噻唑磷微胶囊

制备基于聚乳酸(PLA)改性聚丁二酸丁二醇酯(PBS)为载体的噻唑磷微胶囊。采用溶剂挥发法以聚乙烯醇-1788为乳化分散剂制备微胶囊,通过激光粒度分析仪、光学显微镜、扫描电镜对微胶囊进行形貌表征,用紫外分光光度计研究微胶囊的缓释行为。经聚乳酸(PLA)共混改性后的PBS载体微胶囊的包封率为85.27%、载药量为61.64%,平均粒径为5.46μm,缓释期为30 d。改性后的微胶囊具有较好的形貌,载药量和包封率比纯PBS载体微胶囊高,药物缓释更长。     

萃取精馏的溶剂再生

简要叙述了萃取精馏的溶剂再生工艺过程及重要性,并对溶剂再生中存在的问题进行了分析与总结。     

膜萃取防止溶剂污染的优势

本文以３％ＴＢＰ／苯酚／水为实验体系在不同的膜器中对膜萃取过程中料液对萃取剂的夹带,即溶剂的二次污染进行了研究。在保持膜两侧压降不变的情况下对进口和出口处料液的ＣＯＤ值进行了测定,并与传统的溶剂萃取方法相比较。结果表明,膜萃取中料液中溶剂只有少量的夹带,并且夹带量与操作条件和膜构件基本无关。     

溶剂回流萃取甘草渣黄酮

通过单因素和正交实验考察了各种因素对溶剂法萃取甘草渣黄酮的影响。实验结果获得最佳工艺条件为：溶剂为碱醇质量比为1：2（NaOH浓度：0．4mol／L;乙醇浓度：75％）混合溶液;固液为比1：30;回流时间为3h：回流温度为95℃。在最佳工艺条件下,提取的黄酮含量可达4．210％。     

快速溶剂萃取技术在有机污染物监测中的应用

快速溶剂萃取（ASE）是固体物质中污染物监测的一种样品前处理技术,它根据溶质在不同溶剂中溶解度不同,在较高的温度和压力下选择合适的溶剂,高效、快速地萃取固体或半固体样品中的待测物。阐述了ASE的技术性能和特点,分析了该技术在水环境监测中的应用,探讨了水体有机污染物监测技术的发展前景。     

Solvent Extraction of Fucoxanthin from Phaeodactylum tricornutum

The extraction yield of fucoxanthin from Phaeodactylum tricornutum, a marine diatom, was investigated for 16 h as the functions of the kind of solvent, temperature, and solvent/diatom weight ratio. Acetone, ethanol, and ethyl acetate were used as solvents for the extractions. The extraction yield increased in a saturation manner with the extraction time when the extraction temperatures were 30°C and 40°C. However, the extraction yield increased with time in the early stage of the extraction; thereafter, it was stagnant or decreased with time in the late stage at 50°C, 75°C, and 85°C. The thermal deterioration would suppress the extraction yield in the late stage at those higher temperatures. The maximum extraction yield was obtained at 40°C and no significant benefit in the extraction yield was obtained when the extraction period was extended over 12 h. The extraction yield markedly increased when the solvent/diatom ratio increased from 3/1 to 6/1, but no marked benefit was obtained when the amount of solvent increased over the ratio of 6/1. Ethanol was the most effective solvent in the extraction of fucoxanthin, and the extraction yield was greater in the order of ethanol > acetone > ethyl acetate.     

加速溶剂萃取技术在多环芳烃提取及检测中的应用

多环芳烃的辛醇-水分配系数较高,易被颗粒物吸附,因此检测固体中多环芳烃含量时要对样品进行萃取。加速溶剂萃取是一种全新的液-固萃取技术,具有萃取速度快、萃取剂用量少、样品回收率高等优点,对检测多环芳烃具有重要的应用价值。近几年,加速溶剂萃取技术被应用于提取土壤、水环境沉积物、空气颗粒物、纺织品等物质中的多环芳烃,不同固体样品的萃取温度、压力和萃取剂等萃取条件得到了研究探讨。     

钨萃取平衡分配比的研究

使用一套溶剂萃取平衡的试验装置,选择膦酸三丁酯（ＴＢＰ）为萃取剂,苯为稀释剂,系统地测定了钨的溶剂萃取平衡及萃取条件对萃取平衡分配的影响,可为工业过程设计、工程优化和计算机模拟提供依据。     

超临界流体萃取的溶媒和挟带剂

本文介绍了超临界萃取的原理，溶媒及挟带剂。     

湿法冶金中的溶剂萃取剂

湿法冶金技术对矿物资源的可持续开发、资源的充分利用和环境保护等方面,发挥了很大的作用,随着湿法冶金技术的不断发展和完善,其在冶金生产中占重要的地位。作为湿法冶金的重要手段的溶剂萃取技术也得到广泛的研究和应用,本文介绍了湿法冶金中的萃取剂的历史发展过程,并将传统萃取剂与双端萃取剂进行对比。     

磷酸的溶剂萃取法净化

在全面调研国内外现有的湿法磷酸净化技术的基础上,实验比较了不同萃取剂(正丁醇、TBP、异丁醇和异戊醇)对于磷酸萃取的效果,结果表明,正丁醇对磷酸的萃取效果最好,温度的提高会使磷酸在两相的分配系数略有下降. 溶剂萃取磷酸主要以分子形式进行,因此无机强酸的加入有利于提高磷酸在两相的分配. 比较了正丁醇萃取纯磷酸和粗磷酸的差别,分析了其原因. 正丁醇对金属离子几乎没有萃取效果,因此,溶剂法可以作为一种有效的净化磷酸的方法.     

Dodecylhydroxydiphosphonic Acid for Solvent Extraction

Abstract

The extraction behavior of Zn(II) and Cu(II) in acetate media has been investigated using dodecylhydroxydiphosphonic acid, DHDPA, which was previously synthesized and characterized. The extraction of both cations was carried out in different media with the addition of CH₃COOH, HCl or H₂SO₄ at different pH. The maximum extraction yield of 80% for zinc, was obtained in one step after the addition of sulfuric acid at pH_i=5.5 and for copper after the addition of 10 mg of sodium acetate. The authors plan additional tests using polar solvents.     

Neutron Polarization Analysis for Biphasic Solvent Extraction Systems

We performed neutron polarization analysis (NPA) of extracted organic phases containing complexes, comprised of Zr(NO₃)₄ and tri-n-butyl phosphate, which enabled decomposition of the intensity distribution of small-angle neutron scattering (SANS) into the coherent and incoherent scattering components. The coherent scattering intensity, containing structural information, and the incoherent scattering compete over a wide range of magnitude of scattering vector, q, specifically when q is larger than q* ≈ 1/R_g, where R_g is the radius of gyration of scatterer. Therefore, it is important to determine the incoherent scattering intensity exactly to perform an accurate structural analysis from SANS data when R_g is small, such as the aforementioned extracted coordination species. Although NPA is the best method for evaluating the incoherent scattering component for accurately determining the coherent scattering in SANS, this method is not used frequently in SANS data analysis because it is technically challenging. In this study, we successfully demonstrated that experimental determination of the incoherent scattering using NPA is suitable for sample systems containing a small scatterer with a weak coherent scattering intensity, such as extracted complexes in biphasic solvent extraction systems.     

预分散溶剂萃取技术的研究进展

概述了预分散溶剂萃取过程的发展现状，探讨了预发解溶剂萃以过程中所使用的胶质液体泡沫和胶质气体泡沫的制备，性性和影响泡沫形成的因素以及预分解溶剂萃取研究可能的发展方向和应用前景。