A series of poly(ethylene glycol)(PEG)-4,4'-diphenylmethanediisocyanate(MDI)-poly(dimethylsiloxane ) (PDMS) multiblock copolymers were synthesized by employing two-step growth polymerization technique. Atomic force microscopy (AFM) observed nanoscopically well-organized phase-separated surfaces consisting of hydrophilic domain from PEG and NIDI segments and hydrophobic domain from PDMS segments even with 50 wt.% PDMS in the copolymer, and the multiblock copolymer coatings presented a surface free energy of as low as 6-8 mN m(-1). (c) 2006 Elsevier B.V. All rights reserved.