Polymer coatings with features of differing hydrophilicity, mobility, and topography, distributed across a substrate in microscopic and nanoscopic patches were designed as complex materials equipped with sufficient variability in composition, structure, and dynamics to inhibit interactions associated with biomacromolecular fouling. These complex polymer coatings were prepared by the in situ phase separation and crosslinking of mixtures of hyperbranched fluoropolymer (HBFP) and diamino-terminated poly(ethylene glycol) (PEG), for which the degree of crosslinking, compositions, topographies, and morphologies were varied by alteration of the PEG/HBFP stoichiometries (14, 29, 45, and 55 wt % PEG). This article examines the physicochemical details of HBFP-PEG network coatings prepared on glass substrates, functionalized by 3-aminopropyltriethoxysilane, as characterized by atomic force microscopy (AFM), contact-angle measurements, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetric analysis. Upon incubation in water or artificial seawater, the surfaces underwent reconstruction, which was believed to be driven by the swelling of the PEG domains and the energetic favorability offered by the segregation of PEG to the solid-water interface. (C) 2004 Wiley Periodicals, Inc.