This work explores coatings with thermally switchable wetting behavior, based on block copolymers that possess both hydrophilic and hydrophobic segments. The amphiphilic block copolymers were synthesized by coupling allyl-ended poly(ethylene oxide) (PEO) and hydride-ended poly(dimethylsiloxane) (PDMS) oligomers via a Pt catalyst. One nearsymmetric diblock possessed an order-disorder transition temperature (T-ODT) of 64 degrees C. When cooled through T-ODT in ambient air, the PDMS domains wet the film's surface, producing a hydrophobic coating with a water contact angle (CA) = 90 degrees. However, when cooled in humidified air, hydrophilic PEO domains form at the surface, yielding CA=30-40 degrees. The coatings can be reversibly switched between the two states by reheating above TODT, in the appropriate environment, and then cooling, rapidly generating the desired room-temperature surface wettability. (C) 2015 Wiley Periodicals, Inc.