The synthesis of dipyridyl functionalized polysulfone with improved hydrophilicity and enhanced membrane morphological characteristics is described. The polymer functionalization process involves the formation of lithiated polysulfone from polysulfone (1) and subsequent reaction with excess 2,2'-vinylidenedipyridine (2) in tetrahydrofuran (THF) at -78 degreesC under argon atmosphere to afford the corresponding dipyridyl functionalized polysulfone (3) with an 80% degree of functionalization. The functionalized polymers were characterized by size exclusion chromatography, NMR, FTIR, differential scanning calorimetry and thermogravimetric analysis. Membranes obtained from unmodified polysulfone as well as dipyridyl functionalized polysulfones were characterized by atomic force microscopy, scanning electron microscopy, pure water permeation measurements and contact angle measurements. (C) 2003 Elsevier B.V. All rights reserved.