Preparation and characterization of comb-like PEO gradient surfaces

Comb-like polyethylene oxide (PEG) gradient surfaces where the density of comb-like PEO chains changes gradually along the sample length were prepared on low density polyethylene (PE) sheets by corona discharge treatment with gradually increasing power and graft copolymerization of poly(ethylene glycol) monomethacrylate macromers (PEG-MA), Macromers with PEO chain lengths 1, 5, and 10 were used, The comb-like PEO gradient surfaces prepared were characterized by measurement of the water contact angle, Fourier transform infrared spectroscopy in the attenuated total reflectance mode (FTIR-ATR), and electron spectroscopy for chemical analysis (ESCA), The FTIR-ATR and ESCA measurements indicated that the PEO chains are grafted onto the PE surface with gradually increasing density of PEG. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of PEO chain length and its surface density of polymeric materials. (C) 1996 Academic Press, Inc.