Dual-Channel Solvation Forces at Polymer-Brush Interfaces

Integrating statistical-mechanical pole theory with molecular dynamics simulations, we extend asymptotic correlation theory to polymer-brush-grafted soft interfaces, achieving quantitative, parameter-free predictions of oscillatory solvation free energies. We uncover a dual-channel physical mechanism governing inter-surface forces: interactions across disordered brushes are governed entirely by bulk-liquid correlations (the oscillatory channel), whereas dense, crystalline brushes induce capillary freezing of the confined solvent, opening a monotonic attraction channel of interfacial phase-transition origin.