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Dissolving Technique of polar compounds into supercritical COィイD22ィエD2

极性化合物超临界 COIiD22IeD2 溶解技术

基本信息

批准号：
10450283
负责人：
INOMATA Hiroshi
金额：
$ 6.98万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Supercritical carbon dioxide (scCOィイD22ィエD2) extraction of alkali metal ions from aqueous solutions (K+, Na+ : 1.7 x 10ィイD1-4ィエD1 mol dmィイD1-3ィエD1) with ligands was investigated. Conditions of the experiments were 40℃ with pressure ranging from 10 Mpa to 18 Mpa. Ligands used were crown ethers (18-crown-6, cis-dicyclohexyl-18-crown-6 and 15-crown-5) and glymes (triglyme and tetraglyme). Extraction of KィイD1+ィエD1 or NaィイD1+ィエD1 with ligand in scCOィイD22ィエD2 gave negligibly low recoveries that did not vary with pressure. However, in the presence of an additive, pentadecafluoro-n-octanoic acid (HPFOA), the recoveries increased clearly for both sodium and potassium ion extractions. This is because the HPFOA ionized and apparently supplied its anion which has COィイD22ィエD2-philic fluoro-alkyl chains. Based on the experimental results, a chemical equilibrium model was developed to analyze the extraction mechanism. For crown ether systems, the recoveries showed simple behavior, and the extracted complexes (alkali metal ion : ligand : counter ion) were confirmed to be monomeric (1:1:1). For glymes systems, the recoveries showed various behavior and tended to decrease at high ligand concentrations. This seemed to indicate consecutive complex formation in the aqueous phase. The results of this study show that alkali metals can be extracted with scCOィイD22ィエD2 using ligands and recovery of the metals can be greatly increased by adding a substance that can supply a COィイD22ィエD2-philic counter Ion.Rerading the reverse micell formation, an apparatus for in-situ dynamic laser scattering measurement was developed. With this apparatus, it was found that perfluoro-polyether can be a good surfactant for reverse micell in carbon dioxide in the presence of warer, however direct evidence of the micell could not be obtained because of lackness in agitation power of the experimental setup.

研究了配位体对超临界二氧化碳（scCO_（60）D_（22实验条件为40℃，压力10 ~ 18 MPa。使用的配体是冠醚（18-冠-6、顺-二环己基-18-冠-6和15-冠-5）和甘醇二甲醚（三甘醇二甲醚和四甘醇二甲醚）。用配体在scCO萃取剂D22萃取剂D2中萃取K萃取剂D1 + Na萃取剂D1+ Na萃取剂D1得到的回收率低得可以忽略不计，且不随压力变化。然而，在添加剂，十五氯正辛酸（HPFOA）的存在下，回收率明显增加的钠和钾离子提取。这是因为HPFOA电离并明显提供了其具有CO亲D22亲D2氟烷基链的阴离子。根据实验结果，建立了萃取机理的化学平衡模型。对于冠醚体系，回收率表现出简单的行为，和萃取络合物（碱金属离子：配体：抗衡离子）被证实是单体（1：1：1）。对于甘醇二甲醚体系，回收率表现出各种行为，并在高配体浓度下趋于降低。这似乎表明在水相中连续形成复合物。研究结果表明，scCO_（22）O_（22用该装置发现，在水存在下，全氟聚醚是一种很好的反胶束表面活性剂，但由于实验装置的搅拌能力不足，不能直接得到反胶束的证据。