Figure 5.

PB theory calculations, illustrating the effect of (1) an increase in immobilized negative charge C_P of the probe layer from 0 (black points) to 0.13 mol L⁻¹ (blue line), and (2) an increase in dielectric constant ε_P of the probe layer from 9.1 (blue line) to 10.3 (green points). The shape of the curve traced out by the black points corresponds, approximately, to t = 0 data in Figure 4A, while the green trace can be compared to the t = 60 min data. MCP layer parameters: t_mcp = 0.67 nm, ε _mcp = 4.4, β_j,mcp = 1000 for all ions. Morpholino probe layer parameters:$t_{\mathrm{P}}=0.52\text{nm},{\beta }_{{\text{Na}}^{+},\mathrm{P}}=0,{\beta }_{{\mathrm{H}}_2{\text{PO}}_4^{-},\mathrm{P}}=1.8,{\beta }_{{\text{HPO}}_4^{2-},\mathrm{P}}=1000,{\beta }_{{\text{PO}}_4^{3-},\mathrm{P}}=1000$. Electrolyte parameters: T = 295 °K, 0.2 mol L⁻¹ pH = 7.0 phosphate buffer.