Dry Polymer in Liquid Water

IMMERSION OF A DRY POLYMER IN LIQUID WATER 4.1. Without Incorporation of Tagging Atoms 

When a dry polymer film is immersed into liquid water, an opposite process to what described above takes place. Hydrophilic groups migrate to the interface, and hydrophobic moieties move to the inner part of the surface state of a polymer. The main driving force for these movements is the interfacial tension. The greater the interfacial tension, the greater is the surface configuration change. 

In the presence of both hydrophilic and hydrophobic moieties, the migrations of moieties occur in the direction to minimize the interfacial tension. Therefore, a greater extent of the surface configuration change is observed with amphoteric hydrophobic/hydrophilic polymers. In general, water immersion will make a polymer surface more hydrophilic than the dry film. 

Surface Modification is Applied to Make the Surface Hydrophilic 

The change due to water immersion is minimal, and the decay of surface modification is generally not observed. 

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