Andreaus J, Draxler J, Marr R, Hermetter A
Department of Chemical Engineering and Environmental Technology, Technische Universitat Graz, Inffeldgasse 25, Graz, A-8010, Austria
J Colloid Interface Sci. 1997 Sep 1;193(1):8-16. doi: 10.1006/jcis.1997.5045.
The partitioning behavior of pyrene and anthracene between n-decane and aqueous solutions containing a partially methylated gamma-cyclodextrin (M-gamma-CD) and sodium dodecyl sulfate (SDS) was studied by extraction experiments. At concentrations below the aqueous solubility of pyrene and anthracene both were found to form 1:1 complexes with M-gamma-CD. Formation constants were determined as 1843 M-1 for pyrene and 624 M-1 for anthracene. In micellar solutions of SDS pyrene was found to be better solubilized than anthracene. At constant concentrations of M-gamma-CD the dependence of the partition coefficients on increasing concentrations of SDS could be divided into three linear regions. At concentrations below a critical surfactant concentration (CSCSDS) the partition coefficients of both polyaromatic hydrocarbons as well as the fluorescence intensity of pyrene increased linearly with the addition of SDS. In the fluorescence spectra of anthracene the addition of SDS led to a shift of the maxima to higher wavelengths. These data suggest the formation of ternary complexes of M-gamma-CD with each of the polyaromatic hydrocarbons and SDS. The ternary complex with anthracene was found to be more stable than that of pyrene, which resulted in higher partition coefficients than seen with pyrene. Increasing the surfactant concentrations above the CSCSDS the partition coefficients remained constant until micelles were formed and another linear increase of the partition coefficients could be observed. CSCSDS and the critical micellization concentration (CMC) were found to increase linearly with cyclodextrin concentration. For CSCSDS a molar ratio of 3/1 was found for M-gamma-CD/SDS. Mixed micelles between SDS and gamma-CD are supposed to be formed above CSCSDS. Copyright 1997Academic Press
通过萃取实验研究了芘和蒽在正癸烷与含有部分甲基化γ-环糊精（M-γ-CD）和十二烷基硫酸钠（SDS）的水溶液之间的分配行为。在芘和蒽的水溶度以下的浓度时，发现二者均与M-γ-CD形成1:1络合物。芘的形成常数测定为1843 M-1，蒽的形成常数为624 M-1。在SDS的胶束溶液中，发现芘比蒽的增溶效果更好。在M-γ-CD浓度恒定的情况下，分配系数对SDS浓度增加的依赖性可分为三个线性区域。在低于临界表面活性剂浓度（CSCSDS）时，两种多环芳烃的分配系数以及芘的荧光强度随SDS的加入呈线性增加。在蒽的荧光光谱中，SDS的加入导致最大值向更高波长移动。这些数据表明M-γ-CD与每种多环芳烃和SDS形成了三元络合物。发现与蒽形成的三元络合物比与芘形成的更稳定，这导致其分配系数高于芘。将表面活性剂浓度增加到高于CSCSDS时，分配系数保持恒定，直到形成胶束，此时可观察到分配系数再次线性增加。发现CSCSDS和临界胶束浓度（CMC）随环糊精浓度线性增加。对于CSCSDS，发现M-γ-CD/SDS的摩尔比为3/1。推测在高于CSCSDS时形成了SDS和γ-CD之间的混合胶束。版权所有1997学术出版社
