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The Effect of Multivalent Counterions to the Structure of Highly Dense Polystyrene Sulfonate Brushes



Jing Yu, Jun Mao, Guangcui Yuan, Sushil K. Satija, Wei Chen, Matthew Tirrell


Surface tethered polyelectrolyte brushes are of great importance to many applications, ranging from colloidal stabilization to responsive and tunable materials to lubrication. We synthesized high-density polystyrene sulfonate (PSS) brushes via surface initiated atom-transfer radical polymerization, and performed neutron reflectivity (NR) measurements to investigate the effect of mono-valent Rb+ and tri-valent Y3+ counterions to the structure of the densely tethered PSS brushes. Our NR results show that in monovalent RbNO3 solution, the PSS brush retained its full thickness up to a salt concentration of 1 M, whereas it immediately collapsed upon adding1.67 mM of tri-valent Y3+. Increasing the concentration of Y3+ did not lead to any significant further structure change of the PSS brush. Our findings demonstrate that the presence of multi-valent counterions can significantly alter the structure of polyelectrolyte brushes, which can affect the functionality of the brushes.


polymer brush, polyelectrolyte, multi-valent counterions, neutron reflectometry


Yu, J. , Mao, J. , Yuan, G. , Satija, S. , Chen, W. and Tirrell, M. (2016), The Effect of Multivalent Counterions to the Structure of Highly Dense Polystyrene Sulfonate Brushes, Polymer, [online], (Accessed February 20, 2024)
Created August 18, 2016, Updated October 12, 2021