Gustafsson J, Nylander T, Almgren M, Ljusberg-Wahren H
Department of Physical Chemistry, Uppsala University, Uppsala, S-75121, Sweden
J Colloid Interface Sci. 1999 Mar 15;211(2):326-335. doi: 10.1006/jcis.1998.5996.
The phase behavior of the glycerol monooleate (GMO)-sodium cholate-water (or 0.9 wt% NaCl) system has been examined in the solvent-rich part, using small-angle X-ray scattering and conventional methods. Addition of cholate up to 7% of the total amphiphile swells the cubic phase of the binary GMO-water system so that it takes up almost 70% of water in the salt-free case and 55% in salt. With more bile salt the lamellar phase also appears highly swollen (up to 85% in water, 75% in brine). In the salt solution a small isotropic L3-phase region replaces the lamellar phase at a solvent content of about 79%. The lamellar phase can accept only about 0.2 cholate molecule per GMO, in both water and brine, and a phase with globular micelles (L1) follows and dominates the diagram. No threadlike micelles appear in this system. Investigation of the particle structures with cryo-transmission electron microscopy (TEM) in dilute systems (99% solvent) show globular micelles and coexisting vesicles and globular micelles. In the presence of salt, dilution of the L3 phase results in dispersed globular particles with an irregular internal morphology that suggests they are a dispersed L3 phase. These particles coexist with faceted particles having an inner structure giving a hexagonal pattern in projection, suggested to derive from the cubic phase. The cubic phase in the salt-free systems did not give dispersions stable enough for cryo-TEM examination. Copyright 1999 Academic Press.
采用小角X射线散射和传统方法，研究了富含溶剂部分的甘油单油酸酯（GMO）-胆酸钠-水（或0.9 wt% NaCl）体系的相行为。添加胆酸盐至两亲物总量的7%时，二元GMO-水体系的立方相膨胀，在无盐情况下其含水量几乎达到70%，在有盐情况下为55%。加入更多胆盐时，层状相也会高度膨胀（在水中高达85%，在盐水中为75%）。在盐溶液中，溶剂含量约为79%时，一个小的各向同性L3相区域取代了层状相。在水和盐水中，层状相每GMO只能容纳约0.2个胆酸盐分子，随后出现球状胶束（L1）相并主导相图。该体系中未出现丝状胶束。在稀体系（99%溶剂）中用低温透射电子显微镜（TEM）研究颗粒结构，显示出球状胶束以及共存的囊泡和球状胶束。在有盐存在的情况下，L3相稀释会产生内部形态不规则的分散球状颗粒，表明它们是分散的L3相。这些颗粒与具有内部结构、投影呈六边形图案的多面体颗粒共存，推测后者源自立方相。无盐体系中的立方相无法给出足够稳定的分散体用于低温TEM检测。版权所有1999年学术出版社。
