Self-Consistent Field Analysis of Segregative Aqueous Dextran─Poly(ethylene glycol) Solutions: (3) Polymer-Induced Loop-to-Bridge and Capillary Bridge Forces

When colloidal particles are added to a two-phase system such that the minority phase forms capillary bridges between the particles, then─above the percolation threshold─a strong gel is formed. We focus on an aqueous two-phase system (ATPS) composed of dextran-water-poly(ethylene glycol) (PEG) with dispersed silica particles that are preferentially wetted by the minority PEG-rich phase. This ATPS is characterized by an ultralow interfacial tension between the PEG-rich and dextran-rich phases, es