Anomalous Sorption in Thin Films of Fluoroalkyl-Ended Poly(ethylene glycol)s

Absorption, desorption and swelling behavior of polymers important roles in polymer processing and performance, ranging from issues of dimensional stability permeability to controlling adhesion. Rich, nonlinear are associated with transient swelling and drying of glassy and semicrystalline polymers. Anomalous, -Fickian behaviors are broadly associated with the effects of the penetrant on the dynamics of the . Here we describe anomalous behavior of a type that is associated with a sorbent-triggered -order phase transition. The system of interest is a , semicrystalline polymer with hydrophobic end , placed in contact with humid air.Dueto the strong to absorb water, the melting transition of the can be induced by contact with sufficiently air; during desorption, a sufficient supersaturation reached before nucleation and regrowth of crystals . This leads to very different hysteresis in the sorption isotherm and overshoot in transient sorption than has been reported previously in polymers.