Relaxation phenomena and development of structure in a physically crosslinked nonionic microemulsion studied by photon correlation spectroscopy and small angle x-ray scattering
Relaxation phenomena and development of structure in a physically crosslinked nonionic microemulsion studied by photon correlation spectroscopy and small angle x-ray scattering
复制标题
通过光子相关光谱和小角 X 射线散射研究物理交联非离子微乳液的弛豫现象和结构发展
DOI：
10.1063/1.481207
复制
发表时间：
2000
影响因子：
4.4
通讯作者：
B. Stühn
中科院分区：
文献类型：
--
作者：
M. Schwab;B. Stühn
我们通过小角度x射线散射（SAXS）、光子相关光谱（PCS）和振荡频率扫描实验来研究瞬态网络的静态和动态特性。所研究的体系是一种含有非离子表面活性剂C12E5（五乙二醇单十二烷基醚）的水包油微乳液。微乳液由半径为Rm≈10 nm的胶束（表面活性剂覆盖的球形油滴）组成，分散在水中。在微乳液中加入具有亲水中间嵌段和疏水末端嵌段（硬脂酸-聚环氧乙烷-硬脂酸酯）的三嵌段共聚物，可使胶束相互连接，从而形成瞬态网络。用基于percus_yevick对相关函数的硬球模型描述了三嵌段共聚物加入后的结构行为。在动态光散射实验中，我们观察到三个弛豫过程。快、慢弛豫时间随时间的变化而变化。
We performed small angle x-ray scattering (SAXS), photon correlation spectroscopy (PCS), and oscillatory frequency sweep experiments to investigate the static and dynamic properties of a transient network. The system under investigation is an oil in water microemulsion containing the nonionic surfactant C12E5 (penta ethylene glycol mono dodecyl ether). The microemulsion consists of micelles (spherical oil droplets covered by the surfactant) with radius Rm≈10 nm, which are dispersed in water. Adding a triblock copolymer with a hydrophilic midblock and hydrophobic end blocks (stearate-poly ethylene oxide-stearate) to the microemulsion leads to the interconnection of the micelles and thus to the formation of a transient network. We describe the structural behavior under addition of the triblock copolymer with a hard sphere model based on the Percus–Yevick pair correlation function. In the dynamic light scattering experiment we observe three relaxational processes. The fast and the slow relaxation time vary w...