Figure 2
From: Hydration Repulsion between Carbohydrate Surfaces Mediated by Temperature and Specific Ions
Hydration pressure between carbohydrate surfaces calculated from molecular dynamics simulations.
(a) Snapshot of simulation setup. Note half of the water molecules in the simulation box are not shown for clarity. (b) Density distribution of carbohydrate monomers and waters along surface normal (z axis) within the column of x-y dimensions of the surfaces. The single (*), double (**) and triple stars (***) denote the inner, first and second hydration layers on carbohydrates. (c) Water per carbohydrate monomer, nw and water number density between surfaces as a function of inter-surface distance r. I–V represent different water depolarization, dehydration, or direct interaction regimes (see Text). (d) Net pressure Π acting on carbohydrate surfaces as a function of r calculated from simulations plotted in a semi-logarithmic scale. The exponential decay length λ is fitted for Π(r) from 1 < r < 2 nm. (e) Total, direct and indirect pressure (Π, Πdir and Πind) calculated from simulations. The errors were analyzed from the standard deviation of block averages of simulation time periods 40 to 60, 60 to 80 and 80 to 100 ns. (f) Total, direct and indirect free energy (G, Gdir and Gind) calculated by integrating the pressures in (e) along r.
