SDS-CTAB-H_2O-NaBr双水相系统研究

Phase Behavior of SDS-CTAB-H_2O-NaBr System

实验测定并绘制了十二烷基硫酸钠 ( SDS) -十六烷基三甲基溴化胺 ( CTAB) -水 - Na Br系统的双水相区和偏光区 ,探索了 Na Br对系统的影响。结果表明 :SDS和 CTAB混合表面活性剂的水溶液有两个双水相区 ,双水相的上相为液晶结构 ,具有偏光现象 ;下相为各向同性溶液。 Na Br的加入可改变双水相区和偏光区的位置 ,盐浓度愈大 ,双水相区和偏光区愈向相图两侧移动。当 Na Br浓度高于 0 .2 mol/ L时 ,双水相区与偏光区发生偏离 。

The aqueous two phase region and polarizing regions of sodium dodecyle sulphate (SDS) cetyl trimethyl ammonium bromide (CTAB) H 2O have been determined on a pseudo ternary phase diagram, and the influence of added salt NaBr on them has been observed. It is shown that there are two ATPSs in the aqueous solution of SDS and CTAB mixture, one of them has the cloud point. The upper phase of ATPS is liquid crystal and the lower phase isotropic solution. The added salt NaBr can change the composition of ATPS regions and the polarizing regions. When the salt concentration increases, the position of ATPS region will move to higher concentration of SDS and CTAB. If the concentration of NaBr is higher than 0.2mol/L, the ATPS regions will partly overlapped the polarizing regions and the polarizing phenomenon in the upper phase of some ATPSs will disappear.