Synthesis of photoreactive alpha-4-azidobenzoyl-omega-methoxypoly(ethyleneglycol)s and their end-on photo-grafting onto polysulfone ultrafiltration membranes

Covalent end-on grafting of poly(ethylene glycol) (PEG) onto a polysulfone (PSf) surface using alpha-4-azidobenzoyl-omega-methoxy-PEG (ABMPEG) is desc ribed. Photoreactive ABMPEG was synthesized by reacting monomethoxy-PEG (MP EG) with 4-azidobenzoyl chloride, yielding complete substitution of the hyd roxyl groups. After adsorption from aqueous solutions, ABMPEG was photo-gra fted under wet conditions onto PSf ultrafiltration (UF) membranes. Contact angle (CA) measurements showed the increased hydrophilicity of modified mem branes and the irreversibility of the modification. Bovine serum albumin (B SA) adsorption decreased by 70% and the permeability decay after protein ad sorption became less severe for the modified membranes compared to unmodifi ed reference membranes.