文献名： Structural Study of Polystyrene-b-poly(acrylic acid) Micelles Complexed with Uranyl: A SAXS Core–Shell Model Analysis

作者： Qiang Tian, Di Zhang, Na Li, Mark Julian Henderson, Qintang Li, Guy Royal, Jérémie Courtois, Minhao Yan, Zhichao Zhu, and László Almásy

State Key Laboratory of Environment-Friendly Energy Materials, School of Materials Science and Technology, Southwest University of Science and Technology, Mianyang 621010, China

摘要：The interactions between natural colloidal organic matter and actinides in solutions are complex and not fully understood. In this work, a crew-cut polystyrene-b-poly(acry1ic acid) (PS-b-PAA) micelle is proposed as a model particle for humic acid (HA) colloid with the aim to better understand the sequestration, aggregation, and mobility of HA colloids in the presence of uranyl ions. The effects of uranyl ions on the structure of PS_29k-b-PAA_5k micelles in aqueous solution were mainly investigated by synchrotron small-angle X-ray scattering. A core–shell model, accounting for the thickness and contrast changes of the PAA corona induced by the adsorption of uranyl, was employed to analyze the scattering data. A combination of transmission electron microscopy, dynamic light scattering, and zetametry showed a strong affinity of uranyl ions to PAA segments in water at pH 4–5 that resulted in the shrinkage and improved contrast of the PAA corona, as well as colloidal destabilization at a high uranyl concentration.

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