Abstract
The interaction between two charged walls neutralized by grafted polyelectrolytes and mobile counterions is studied using a simplified model system, in which the charged monomers of the polyelectrolyte are replaced by 'grafted' ions that interact with the grafting wall via a one-dimensional potential. Using a mean-field approximation, the model is solved numerically, and some analytic results are obtained for large separations. The behavior of the mean-field solution is checked against Monte Carlo simulations of grafted polyelectrolyte chains and is found to agree qualitatively. In salt-free systems there is generally a long-range repulsion due to free counterions, and then a short-range bridging attraction if sufficient polyelectrolyte is present. The addition of salt screens the long-range repulsion and usually lowers the pressure. A bridging attraction can occur at short-range and is significant mainly when the effective surface charge of the wall plus grafted polyelectrolyte is small.
| Original language | English |
|---|---|
| Pages (from-to) | 7116-7125 |
| Number of pages | 10 |
| Journal | Langmuir |
| Volume | 16 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - 5 Sept 2000 |
| Externally published | Yes |