Figure 17: Adsorption and wetting of a polymer onto a solid surface.
The solvent is shown in blue and the solid surface is shown in gray. The red chains indicate a polymeric species able to undergo phase separation at the proper conditions. The yellow dashed curves outline the adsorbing or wetting polymers. In (A), the polymer is in the one-phase regime and adsorbs onto the substrate. In (B) and (C), the polymer has undergone phase separation and the nascent dense phase partially wets the surface. The contact angle, θY, may be above 90°, indicating poor wetting (B), or below 90°, indicating good wetting (C). In (D), the polymer-rich dense phase completely wets the surface.