The effects of the surface energy, storage modulus (G'), and glass-transition temperature (T-g) on the biofouling behavior of siloxane and fluorosiloxane polymer surfaces (films) were studied. Irregular Si-H-terminated tetrabranched star oligosiloxanes and star oligofluorosiloxanes were prepared by the acid-catalyzed equilibration of octamethylcyclotetrasiloxane or 1,3,5-trimethyl-1,3,5-tris(3',3',3'-trifluoropropyl)cyclo-trisiloxane with tetrakis(dimethylsiloxy)silane, respectively. Terminal epoxy groups were introduced via Pt-catalyzed hydrosilylation with allyl glycidyl ether to yield compounds that were subsequently crosslinked with alpha,omega-bis(3-aminopropyl)poly(dimethylsiloxane). The resulting films were characterized by goniometry, dynamic mechanical thermal analysis, and thermogravimetric analysis. The foul-release behavior was studied by the measurement of how strongly sporelings (young plants) of the green seaweed Ulva adhered. The corrosion protection of aluminum was evaluated by electrochemical impedance spectroscopy. Fluorosiloxane films displayed higher G' and T-g values, decreased contact angles (with water), and more effectively released Ulva sporelings in comparison with siloxane films. (c) 2006 Wiley Periodicals, Inc.