Six systems were prepared to model each solute, DS -, DS 0 , and SO 4 CH - 2 (see Sec. II E), binding to the ACWI, and the bare AWI. The ACWI systems contain 8038 water molecules, 48 C 12 E 6 molecules at the surface, and one solute. Note that systems with ionic solutes (DS - or SO 4 CH - 2 ) were simulated without any Na + counter ion (i.e. with a net -1 charge). As is common in many codes, a background neutralizing charge is added to the reciprocal space part of the Ewald sum. The ACWI system was initially prepared by running constant surface tension simulations 32 using the experimental surface tension corresponding to the CMC. This yielded an interfacial surface coverage of 60 molecules per Å2 which is consistent with previous results. The AWI systems contain 8038 water molecules and one solute. All systems were simulated at constant volume in an orthorhombic box with dimensions 5 nm by 5 nm by 30 nm with periodic boundary conditions in each direction. Simulated at room temperature, the liquid water phase occupies around 10 nm in the z-direction, with the remaining ∼ 20 nm representing the vacuum phase.