Self-consistent field theory of polyelectrolyte brushes with finite chain extensibility

Inna O. Lebedeva (1, 2) , E.B. Zhulina (3, 4) , Oleg V. Borisov (1, 4, 2, 3)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
2 SPSPU - Saint Petersburg State Polytechnical University
3 Institute of Macromolecular Compounds
4 St. Petersburg National University of Informational Technologies

Polyelectrolyte brushes are formed by charged macromolecules tethered by the end segment to a solid-liquid interface. At low ionic strength of the solution, the intermolecular electrostatic interactions lead to strong stretching of the macromolecules that may, as a result, approach the limit of their extensibility (the contour length). Here, we present an analytical theory of polyelectrolyte brushes developed within the Poisson-Boltzmann approximation which explicitly accounts for finite extensibility of the brush-forming chains. In contrast to earlier theories based on the approximation of Gaussian elasticity of the brush-forming chains, the current approach enables avoiding artificial result of stretching of the chains beyond the contour length at high degrees of ionization or/and large grafting densities.

Domaines: Polymères; Chimie théorique et/ou physique

Inna O. Lebedeva, E.B. Zhulina, Oleg V. Borisov. Self-consistent field theory of polyelectrolyte brushes with finite chain extensibility. Journal of Chemical Physics, 2017, 146 (21), pp.214901. ⟨10.1063/1.4984101⟩. ⟨hal-01736862⟩