文献类型：期刊文献

英文题名：Enrichment and distribution of counterions in spherical polyelectrolyte brushes probed by SAXS

作者：Ye, Zhishuang[1];Li, Li[1];Zhao, Fang[1];Tian, Yuchuan[1];Wang, Yunwei[1];Yang, Qingsong[1];Dai, Liheng[1];Guo, Xuhong[1,2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Shihezi Univ, Engn Res Ctr Mat Chem Engn Xinjiang Bingtuan, Xinjiang 832000, Peoples R China;[3]East China Univ Sci & Technol, Int Joint Res Ctr Green Energy Chem Engn, Shanghai 200237, Peoples R China

年份：2019

卷号：57

期号：12

起止页码：738

外文期刊名：JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS

收录：;EI(收录号：20191706818170);WOS:【SCI-EXPANDED(收录号:WOS:000469936600002)】；

基金：We gratefully thank the financial support from the NSFC Grants (51761135128 and 51773061) and Key Bingtuan (2018AB025), and the technical support from Shanghai Synchrotron Radiation Facility.

语种：英文

外文关键词：counterion distribution; counterion enrichment; SAXS; spherical polyelectrolyte brush

摘要：The spatial correlation of counterions [Li+, Na+, Rb+, Cs+, NH4+, (CH3)(4)N+] with spherical polyelectrolyte brushes (SPBs), which consist of a PS core and chemically grafted PSS chains, was comprehensively studied through a combination of SAXS, DLS, and Zeta potential. Results show that the SAXS intensity profiles of the brush appears to be "insensitive" to the concentration of Na+. By contrast, introducing salt ions with a density lower than sodium [NH4+, (CH3)(4)N+ and Li+] into the brush layer will cause a decrease in the scattering intensity while introducing those with a higher density than sodium (Rb+ and Cs+) will cause the opposite result. As verified by the combined results of SAXS, DLS, and Zeta potential, the collapse of the brush and the enrichment of the counterions in the brush layer occur simultaneously. It was further demonstrated that the concentration of counterions enriched in the innermost layer of the brush shell can be enhanced up to hundreds of times compared with the bulk concentration, and the counterion distribution in SPB shell follows a radial attenuation distribution. SAXS is confirmed to be powerful in probing the enrichment and distribution of counterions within SPB. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 738-747