Ion conduction and phase morphology in sulfonate copolymer ionomers based on ionic liquid–sodium cation mixtures
作者:Siti Aminah Mohd Noor、Daniel Gunzelmann、Jiazeng Sun、Douglas R. MacFarlane、Maria Forsyth
DOI:10.1039/c3ta13835f
日期:——
A series of sulfonate based copolymer ionomers based on a combination of ionic liquid and sodium cations have been prepared in different ratios. This system was designed to improve the ionic conductivity of ionomers by partially replacing sodium cations with bulky cations that are less associated with anion centres on the polymer backbone. This provides more conduction sites for sodium to âhopâ to in the ionomers. Characterization showed the glass transition and 15N chemical shift of the ionomers did not vary significantly as the amount of Na+ varied, while the ionic conductivity increased with decreasing Na+ content, indicating conductivity is increasingly decoupled from Tg. Optical microscope images showed phase separation in all compositions, which indicated the samples were inhomogeneous. The introduction of low molecular weight plasticizer (PEG) reduced the Tg and increased the ionic conductivity significantly. The inclusion of PEG also led to a more homogeneous material.
以离子液体和钠离子的不同比例组合为基础,制备了一系列磺酸盐共聚物离子聚合物。该系统旨在通过用与聚合物骨架上的阴离子中心关联较少的笨重阳离子部分取代钠阳离子,从而提高离子聚合物的离子传导性。这就为钠在离子聚合物中提供了更多的传导位置。表征结果表明,离子聚合物的玻璃化转变和 15N 化学位移随 Na+ 含量的变化而变化不大,而离子电导率则随 Na+ 含量的降低而增加,这表明电导率与 Tg 越来越不相关。光学显微镜图像显示,所有成分都存在相分离现象,这表明样品是不均匀的。低分子量增塑剂(PEG)的引入降低了 Tg,并显著提高了离子电导率。PEG 的加入也使材料更加均匀。