SDBS/(C_(12)-4-C_(12))Br_(2)复配微乳液相行为影响因素研究

Study on the influencing factors of phase behavior of SDBS/(C_(12)-4-C_(12))Br_(2) microemulsion

微乳液因其优良特性被广泛应用于三次采油、化妆品、食品工业等领域。为了探究阴/阳离子表面活性剂复配微乳液体系的相行为影响因素,研究了SDBS与(C_(12)-4-C_(12))Br_(2)的最佳摩尔比以及盐度、表面活性剂质量分数、油水比的影响。研究表明,对于SDBS-(C_(12)-4-C_(12))Br_(2)/正丁醇/Na Cl/水/煤油体系,增溶参数随着SDBS与(C_(12)-4-C_(12))Br_(2)摩尔比的增加呈现先增加后减小的趋势,最终确定SDBS与(C_(12)-4-C_(12))Br_(2)的最佳摩尔比为0.7∶1。盐扫实验中,随着Na Cl质量分数的增加,体系呈现出Winsor Ⅰ型→Winsor Ⅲ型→Winsor Ⅱ型的相态转变。油扫实验中,随着油水比的增加,当Na Cl质量分数较低时,体系发生由胶团溶液到Winsor Ⅰ型的转变;当Na Cl质量分数足够高时,体系呈现出Winsor Ⅱ型→Winsor Ⅲ型→WinsorⅠ型的相态转变。此外Winsor Ⅲ型微乳液形成和消失所需要的油量随着NaCl和复合表面活性剂的质量分数增加而增加。

Microemulsions are widely used in tertiary oil recovery,cosmetics, food industry and other fields due to their excellent properties.By mixing anionic and cationic surfactants, a microemulsion system with excellent performance could be prepared. The factors influencing the phase behavior of the microemulsion system of mixed anionic/cationic surfactants, such as the molar ratio of SDBS to (C_(12)-4-C_(12))Br_(2), salinity, surfactant mass fraction, and oil-water ratio, were studied.The results show that, for the SDBS-(C_(12)-4-C_(12))Br_(2)/n-butanol/Na Cl/water/kerosene system, the solubilization parameter shows a trend of first increase and then decrease with the increase of the molar ratio.The optimal molar ratio of SDBS to (C_(12)-4-C_(12))Br_(2) is 0.7∶1. In the experiments to investigate the effects of salt, the oil-water ratio was fixed to 1∶1, and the mass fractions of mixed surfactants were 2%, 3%,4% and 5%, respectively. With the increase of NaCl mass fraction, all systems show the phase transition from Winsor Ⅰ→Winsor Ⅲ→WinsorⅡ. In the experiments to investigate the effects of oil, the mass fraction of mixed surfactants was fixed to 4%, and the mass fractions of NaCl were 0.50%, 1.30% and 1.65%, respectively. With the increase of the oil-water ratio, when the NaCl mass fraction was 0.50%, the system changed from micellar solution to Winsor Ⅰ type;when the NaCl mass fractions were 1.30% and 1.65%, the two systems showed the phase transition from Winsor Ⅱ→Winsor Ⅲ→Winsor Ⅰ. When the Na Cl mass fraction was fixed to 1.30% and the mass fractions of mixed surfactants were 3%, 4% and 5% respectively, with the increase of the oil-water ratio, all systems showed the phase transition from WinsorⅡ→Winsor Ⅲ→Winsor Ⅰ. In addition, the amounts of oil required for the formation and disappearance of Winsor Ⅲ microemulsion increased with the mass fractions of NaCl and mixed surfactants.