Static Contact Angle of Sessile Air Bubbles on Polymer Gel Surfaces in Water

摘要: We have measured the static contact angle of sessile air bubbles in water on poly (N-isopropylacrylamide) (NIPA) gel surfaces. The temperature dependence was two different kinds samples, consisting homogeneous networks (transparent) and phase-separated (opaque). It found that transparent exhibits a sharp but continuous decrement upon heating vicinity transition point, while opaque does not show any appreciable change. absolute value collapsed state is evidently smaller than gel. These results were qualitatively discussed terms only chemical also physical surface properties response to change; former balance hydrophobic-hydrophilic interactions this system, latter includes polymer density, roughness, network inhomogeneity.