Applications of Room Temperature Ionic Liquid: Extraction and Catalysis
| Autor: | Zusing Yang, 楊儒興 |
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| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 Room Temperature Ionic Liquids (RTILs) have been widely employed as novel solvents for many applications, such as liquid/liquid extraction, chromatography, synthesis, catalysis etc. This is because of their unique chemical and physical properties of high polarity, high thermal stability, negligible vapor pressure, low toxicity, low melting temperature and good electrochemical stability. The use of RTILs for liquid/liquid extraction and synthesis is noted for their nonvolatile and thermally stable properties. In catalysis, RTILs play the important roles of solvent as well as catalyst. Hence, RTILs are regarded as “green solvents”. The properties of RTILs change with their structure. For example, RTILs could be water immiscible, such as [BMIM+][PF6-], or water miscible, such as [BMIM+][BF4-]. In this work, we report the applications of [BMIM+][PF6-] for extractions and catalysis. For liquid/liquid extraction and liquid membrane extraction of metal ions and phase transfer of metal nanoparticles with [BMIM+][PF6-] were investigated. In metal ions extraction, RTIL was employed as a novel solvent to extract metal ions from aqueous phase into ionic liquid phase. The extraction behavior of RTIL is similar to that of volatile organic solvents (VOCs). For liquid membrane extraction of metal ions, RTIL was employed as membrane solvent to extract and recover metal ions in a continuous step successfully. For phase transfer of gold nanoparticles with RTIL, the sizes and shapes of gold nanoparticles do not change after transferring with RTIL. Other metal nanoparticles, such as silver and palladium nanoparticles could also be transferred to RTIL without changing the size distribution. This approach offers the potential for the combination of nanoparticles with green solvent for further investigation; we examined the catalytic behavior of dyes on photocatalysis. The photodecomposed rate of dye in RTIL is faster than that in pure water. Further, the rate of photodecomposition of dye in RTIL containing TiO2 is faster than that in RTIL. As TiO2 was capped with gold nanoparticles in RTIL, the photodecomposed rate of dye in RTIL further enhanced. These preliminary results indicate that phase transfer of metal nanoparticles with RTIL allows the opportunity of exploring the potential catalytic behavior of metal nanoparticles in RTILs. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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