Wang Yunwei, Li Li, Wang Yiming, Yang Qingsong, Ye Zhishuang, Fu Zhinan, Sun Liang, Guo Xuhong
State Key Laboratory of Chemical Engineering, Engineering Research Center of Large Scale Reactor Engineering and Technology (Ministry of Education), and International Joint Research Center of Green Energy Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China.
Engineering Research Center of Xinjiang Bingtuan of Materials Chemical Engineering, Shihezi University, Shihezi, Xinjiang 832000, P.R. China.
Langmuir. 2021 Jun 1;37(21):6388-6396. doi: 10.1021/acs.langmuir.1c00026. Epub 2021 May 19.
By combining small-angle X-ray scattering, wide-angle X-ray scattering, and rheology, the effect of additional polyelectrolyte chains on interactions among spherical polyelectrolyte brushes (SPB) was systematically investigated both on microscopic and macroscopic levels. The negatively charged poly(acrylic acid) (PAA) chains and positively charged poly(dimethyl diallyl ammonium chloride) (PDDA) chains were used as additional polyelectrolyte chains to investigate the local ordered structure and the "polyelectrolyte peak" among SPB. Interestingly, coacervation appeared in the SPB emulsion while introducing additional free polyelectrolyte chains. The addition of excess positively charged PDDA chains would lead to the transformation of the SPB emulsion from the coacervation to the aggregation, while it has not been observed in the case of PAA chains. Moreover, it was further confirmed that the specific local ordered structure was caused by the electrostatic interaction among polyelectrolyte chains of adjacent SPB. This work could enrich our understanding of polyelectrolyte assembly in concentrated SPB, thereby greatly broadening the application fields of SPB.
通过结合小角X射线散射、广角X射线散射和流变学，从微观和宏观层面系统地研究了额外的聚电解质链对球形聚电解质刷（SPB）间相互作用的影响。使用带负电荷的聚丙烯酸（PAA）链和带正电荷的聚二甲基二烯丙基氯化铵（PDDA）链作为额外的聚电解质链，以研究SPB中的局部有序结构和“聚电解质峰”。有趣的是，在引入额外的游离聚电解质链时，SPB乳液中出现了凝聚现象。添加过量带正电荷的PDDA链会导致SPB乳液从凝聚转变为聚集，而在PAA链的情况下未观察到这种现象。此外，进一步证实了特定的局部有序结构是由相邻SPB的聚电解质链之间的静电相互作用引起的。这项工作可以丰富我们对浓SPB中聚电解质组装的理解，从而极大地拓宽SPB的应用领域。
