SANS from Pluronic P85 in d-water
SANS from Pluronic P85 in d-water
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DOI：
10.1016/j.eurpolymj.2010.10.012
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发表时间：
2010-12-01
影响因子：
6
通讯作者：
Hammouda, Boualem
中科院分区：
文献类型：
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作者：
Hammouda, Boualem
用小角中子散射（SANS）方法研究了Pluronic P85（EO（26）PO（40）EO（26））共聚物在氘代水中的结构。在宽的样品温度窗口下测量了一系列P85级分。报告了富相行为。在低于临界胶束形成条件下观察到单聚体。在固定的P85分数，胶束相的数量观察后，温度升高：第一个球形胶束，然后圆柱形胶束，然后层状胶束。在最高温度下，观察到分层的层状相。SANS数据的分析包括拟合经验Guinier-Porod模型，该模型适用于低P85分数下各个阶段的数据拟合。当P85分数增加时，包括颗粒间结构因子以分析来自浓缩球形胶束的SANS数据。在高P85分数下，观察到次晶结构，这由增强的颗粒间相互作用峰证明。获得了P85/d-水的相图，显示了各种相。针对一种样品组合物的球形胶束相，使用核-壳模型来拟合SANS数据并获得尺寸和散射长度密度。使用物质平衡方程，诸如聚集数（即，每个胶束的Pluronic大分子数）和壳区域中的水合水分子数。爱思唯尔有限公司出版
Small-angle neutron scattering (SANS) has been used to investigate Pluronic P85 (EO(26)PO(40)EO(26)) copolymer in deuterated water. A range of P85 fractions were measured for a wide sample temperature window. A rich phase behavior is reported. Unimers were observed below the critical micelle formation condition. At fixed P85 fraction, a number of micellar phases were observed upon increasing temperature: first spherical micelles, then cylindrical micelles, then lamellar micelles. At the highest temperature, a demixed lamellae phase was observed. Analysis of the SANS data consisted in fits to an empirical Guinier-Porod model that was appropriate for data fitting in the various phases at low P85 fractions. When the P85 fraction increased, an inter-particle structure factor was included to analyze SANS data from concentrated spherical micelles. At high P85 fractions, paracrystalline structures were observed as evidenced by an enhanced inter-particle interaction peak. A phase diagram for P85/d-water was obtained showing the various phases. Focusing on the spherical micelles phase for one sample composition, a core-shell model was used to fit SANS data and obtain sizes and scattering length densities. Using material balance equations, information such as the aggregation number (i.e., number of Pluronic macromolecules per micelle) and the number of hydration water molecules in the shell region are determined. Published by Elsevier Ltd.