探討單磷及雙磷溫敏性離子液體做為正滲透提取液之效能表現
Exploring the Performance-Affecting Factors of Monocationic and Dicationic Phosphonium-Based Thermoresponsive Ionic Liquid Draw Solutes in Forward Osmosis期刊論文
磷系溫敏性離子液體材料，基於其易於分離的特性，因此具有做為正滲透提取液之應用潛力。磷系溫敏性離子液體在正滲透端驅動力與相分離特性是兩個影響正滲透技術效能的兩個主要因素，本研究針對這兩個影響因素探討具有低臨界溶液溫度特性之單磷與雙磷陽離子搭配不同陰離子，包含對甲苯磺酸根、馬來酸根、三甲基苯磺酸根，這些陰陽離子的結構會影響其相變時的霧點。含有高親水性陰離子之磷系提取液，其霧點較高。單磷與雙磷陽離子搭配相同陰離子時，雙磷離子液體之霧點會低於單磷離子液體之霧點。離子液體水溶液在正滲透驅動力表現上會受滲透壓與黏度影響，因此具有高滲透壓與與低黏度之單磷離子液體水溶液在正滲透測試中有較大的正滲透驅動力與水通量。在正滲透程序後，稀釋的離子液體提取液在高於低臨界溶液溫度時會形成水富相與提取液富相，具有較低滲透壓的磷系離子液體在水富相的殘留量較低。
Because of easy recovery, thermoresponsive phosphonium-based ionic liquids (ILs) can be used as a potential draw solute in forward osmosis (FO). Its phase separation behaviors and water-drawing potential are two main factors affecting FO performance. In this study, these two factors were investigated for the lower critical solution temperature (LCST) type mono-cationic and di-cationic phosphonium-based IL draw solutes with different anions, including p-toluenesulfonate (TSO), hydrogen maleate (Mal), and trimethylbenzenesulfonate (TMBS). In phase separation behaviors, the structure chemistry of cation/anion can affect the LCST cloud temperature point (Tcloud). High hydrophilicity of the anion leads to high LCST Tcloud of phosphonium-based IL aqueous solution. For the same anion, the LCST Tcloud of di-cationic phosphonium-based IL is lower than that of mono-cationic phosphonium-based IL. In water-drawing potential, it is related to the osmolality and the viscosity of IL aqueous solution. Mono-cationic phosphonium-based IL aqueous solution with high osmolality and low viscosity has high water-drawing potential and water flux in FO test. After FO process, diluted IL draw solution is phase separated into IL-rich layer and water-rich layer above LCST. Phosphonium-based IL with low osmolality can lead to low residual IL content in water-rich layer.
Because of easy recovery, thermoresponsive phosphonium-based ionic liquids (ILs) can be used as a potential draw solute in forward osmosis (FO). Its phase separation behaviors and water-drawing potential are two main factors affecting FO performance. In this study, these two factors were investigated for the lower critical solution temperature (LCST) type mono-cationic and di-cationic phosphonium-based IL draw solutes with different anions, including p-toluenesulfonate (TSO), hydrogen maleate (Mal), and trimethylbenzenesulfonate (TMBS). In phase separation behaviors, the structure chemistry of cation/anion can affect the LCST cloud temperature point (Tcloud). High hydrophilicity of the anion leads to high LCST Tcloud of phosphonium-based IL aqueous solution. For the same anion, the LCST Tcloud of di-cationic phosphonium-based IL is lower than that of mono-cationic phosphonium-based IL. In water-drawing potential, it is related to the osmolality and the viscosity of IL aqueous solution. Mono-cationic phosphonium-based IL aqueous solution with high osmolality and low viscosity has high water-drawing potential and water flux in FO test. After FO process, diluted IL draw solution is phase separated into IL-rich layer and water-rich layer above LCST. Phosphonium-based IL with low osmolality can lead to low residual IL content in water-rich layer.
作者：劉柏逸,王鈞逸,何佳樺,陳意君,鐘琍菁,梁德明,張敏超,洪仁陽
★文章出處：Desalination and Water Treatment (2020/10/01)
