聚环氧乙烷在纯溶剂和混合溶剂中的介观扩散

Mesoscopic Diffusion of Poly(ethylene oxide) in Pure and Mixed Solvents.

作者信息

Zheng Xiong, Anisimov Mikhail A, Sengers Jan V, He Maogang

机构信息

Institute for Physical Science and Technology and Department of Chemical and Biomolecular Engineering , University of Maryland , College Park , Maryland 20742 , United States.

Key Laboratory of Thermo-Fluid Science and Engineering , Ministry of Education, Xi'an Jiaotong University , Xi'an , Shaanxi Province 710049 , People's Republic of China.

出版信息

J Phys Chem B. 2018 Apr 5;122(13):3454-3464. doi: 10.1021/acs.jpcb.7b10420. Epub 2017 Nov 27.

DOI:10.1021/acs.jpcb.7b10420

PMID:29131952

Abstract

We present results from an experimental dynamic light-scattering study of poly(ethylene oxide) (PEO) in both a pure solvent (water) and a mixed solvent (tert-butanol + water). The concentration dependence of the diffusive relaxation of the PEO molecules is found to be typical of polymers in a good solvent. However, the mesoscopic diffusive behavior of PEO in the mixed solvent is very different, indicating an initial collapse and subsequent reswelling of PEO caused by co-nonsolvency. Furthermore, in the solutions of PEO with very large molecular weights, we found additional hydrodynamic modes indicating the presence of PEO clusters and aggregates similar to those found by some other investigators.

摘要

我们展示了对聚环氧乙烷（PEO）在纯溶剂（水）和混合溶剂（叔丁醇 + 水）中进行的实验动态光散射研究结果。发现PEO分子扩散弛豫的浓度依赖性是聚合物在良溶剂中的典型特征。然而，PEO在混合溶剂中的介观扩散行为非常不同，这表明由于共非溶剂化作用，PEO会先发生塌缩，随后再溶胀。此外，在分子量非常大的PEO溶液中，我们发现了额外的流体动力学模式，这表明存在类似于其他一些研究者所发现的PEO簇和聚集体。