The addition of salt modifies the range of electrostatic interactions through the Debye-screening. In recent studies we have analyzed how the brush height is changing with the concentration of salt inside the (good) solvent. The molecular dymamics simulations, featuring explicit salt ions (red squares), were in close agreement with an approximate simulation with Debye screening potential (black dots) and self-consistent field calculations using Biesheuvel's approach (green triangles), but in qualitative disagreement with previously published mean-field approaches (green dashed and magenta dotted curves). Considering the interplay of charge-balance, excluded volume and entropic spring interactions we have developed a Flory-type mean field approach which is capable of fitting the simulation data accurately (blue curve).
- Su-Zhen He, Holger Merlitz, Long Chen, Chen-Xu Wu and Jens-Uwe Sommer, Polyelectrolyte brushes: MD simulation and SCF theory, Macromolecules 43, 7845 (2010)
- Long Chen, Holger Merlitz, Su-zhen He, Chen-Xu Wu and Jens-Uwe Sommer, Polyelectrolyte Brushes: Debye Approximation and Mean-Field Theory, Macromolecules 44, 3109 (2011)