Attractive double-layer forces between neutral hydrophobic and neutral   hydrophilic surfaces
  The interaction between surface patches of proteins with different surface properties has a vital role to play driving conformational changes of proteins in different salt solutions. We demonstrate the existence of ion-specific attractive double-layer forces between neutral hydrophobic and hydrophilic surfaces in the presence of certain salt solutions. This is done by solving a generalized Poisson-Boltzmann equation for two unequal surfaces. In the calculations we utilize parameterized ion-surface-potentials and dielectric-constant-profiles deduced from recent non-primitive-model molecular dynamics (MD) simulations that account partially for molecular structure and hydration effects. 
Eduardo R. A. Lima, Mathias Bostr\"om, Nadine Schwierz, Bo E.   Sernelius, and Frederico W. Tavares
cond-mat.soft cond-mat.mes-hall physics.bio-ph