測量界面活性劑於1,1,1,2-Tetrafluoroethane之溶解度

Abstract

測量界面活性劑於1,1,1,2-Tetrafluoroethane之溶解度 學生：李介仁 指導教授：余 艇 國立交通大學應用化學所 摘要 利用超臨界二氧化碳或是液態二氧化碳來萃取物質，在過去已被廣泛研究，由於其非極性的特性， 只有非極性或是低極性的物質才能溶解其中。然而親水性物質，如蛋白質，已被證實可以溶解於含 氟界面活性劑的二氧化碳中，而且是藉由微胞的形式將蛋白質溶解。超臨界二氧化碳的特性是在減 壓過程中會逸散至空氣中，而可以將萃取物直接濃縮，無須其他額外的濃縮過程，然而要維持超臨 界二氧化碳或是液態二氧化碳的溶解能力往往需要較高的壓力，如壓力需大於100 bar因此造成實用 上的限制。本研究是利用冷媒1,1,1,2-tetrafluoroethane(R134a )來取代傳統的二氧化碳做為溶劑，藉由 添加陽離子型界面活性劑trioctylmethylammonium chloride(TOMAC)，成功溶解親水性物質甲基橙及蛋 白質cytochrome c，並且由甲基橙所產生的紅位移，證實有微胞結構形成於冷媒中。另外，於本研究 中亦測量一些界面活性劑如 sodium bis-2-ethylhexyl sulfosuccinate ( AOT ), didodecyldimethylammonium bromide (DDAB), n-dodecyltrimethylammonium chloride (DTAC) 及 cetyltrimethylammonium chloride (CTAC)，於冷媒R134a的溶解度，並改變冷媒R134a的壓力、溫度及添加輔助溶劑等因素，來探討這 些因素對界面活性劑於冷媒R134a中溶解度的影響。由於冷媒R134a只需在相對低壓之下就可以液化， 相信在實用上，比使用二氧化碳有價值。

Solubility Measurements of Surfactants in 1,1,1,2-Tetrafluoroethane Student : Jie-Ren Li Advisor : Tiing Yu Department of Applied Chemistry, National Chiao Tung University Abstract Extraction of analytes from solid and liquid matrixes using supercritical or liquid carbon dioxide ( SFCO2 ) has been extensively studied in the past. Due to its non-polar property, only less polar components are soluble in carbon dioxide. However, hydrophilic species, such as proteins can be dissolved in carbon dioxide with certain florinated surfactants. Micelle formation was proved responsible for the solubilization. Carbon dioxide turns into gas after extraction that spares the endeavor of further concentrating the collected analytes. However, the operative pressures for maintaining adequate solvent strength for supercritical or liquid carbon dioxide can be well above 100 bar; this may depreciate the value for practical application. We replaced carbon dioxide with the ozone-depletion free refrigerant 1, 1, 1, 2-tetrafluoroethane (R134a) as the solvent in this study. Hydrophilic compounds, methyl orange and cytochrome c can be solubilized in liquid R134a in the presence of cationic surfactant trioctylmethylammonium chloride ( TOMAC ). Significant red shift of methyl orange in liquid R134a in the presence of TOMAC indicates micelles were formed in liquid R134a. We also measured the solubilities of some commercial surfactants such as, sodium bis-2-ethylhexyl sulfosuccinate ( AOT ),didodecyldimethyl- ammonium bromide ( DDAB ), n-dodecyltrimethylammonium chloride ( DTAC ) and cetyltrimethylammonium chloride (CTAC) in R134a. The measurements were performed in the pressure range from 15 to 100 bar at the temperature range from 15 to 350C. In addition to the effects of pressure and temperature, the influence of cosolvent will also be discussed. AOT shows better solubility in R134a than those of other surfactants. R134a also becomes gas after extraction and separates from the collected analytes; therefore possesses the same advantage like carbon dioxide. Since the operative pressure for R134a can be as low as 10 bar, it may prove to be more practical than using carbon dioxide as the extraction solvent. Accordingly, it may be applied to recover hydrophilic compounds of low concentration from aqueous solution in the presence of surfactant.