Effect of Counterions on the Interaction among Concentrated Spherical Polyelectrolyte Brushes

Polymers

Liang Sun¹  Li Li²  Yiming Wang²  Zhishuang Ye²  Qingsong Yang²  Yunwei Wang²  Fan Yang²  Xuhong Guo² 

[1] Engineering Research Center of Xinjiang Bingtuan of Materials Chemical Engineering, Shihezi University, Shihezi 832000, China;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, China;

关键词: spherical polyelectrolyte brush;    counterions;    WAXS;    rheology;    SAXS;   

DOI  :  10.3390/polym13121911

来源: DOAJ

【 摘 要 】

The effect of counterions on interactions among spherical polyelectrolyte brushes (SPBs) was systematically investigated by rheology, small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The SPB particles consist of a solid polystyrene (PS) core with a diameter of ca.100 nm and a chemically grafted poly-(acrylic acid) (PAA) brush layer. Metal ions of different valences (Na⁺, Mg²⁺ and Al³⁺) were used as counterions to study the interactions among concentrated SPBs. The so-called “structure factor peak” in SAXS, the “local ordered structure peak” in WAXS and rheological properties indicated the interactions among concentrated SPBs. Combining SAXS, WAXS and rheology, the formation mechanism of the local ordered structure among PAA chains in the overlapped area of adjacent SPB, which was generated due to the bridge function of counterions, was confirmed. In contrast, excessive counterions shielded the electrostatic interaction among PAA chains and destroyed the local ordered structure. This work enriches our understanding of the polyelectrolyte assembly in concentrated SPBs under the effect of counterions and lays the foundations for SPB applications.

【 授权许可】

Unknown