Characterization of Grafted Poly(ethylene glycol) on Si Wafers Using Scanning Probe Microscopy

The uniformity and surface topography of grafted poly(ethylene glycol) (PEG) coatings were characterized at the microscale as a function of grafting temperature (grafting density) using scanning probe microscopy. Images of PEG-coated silicon wafers show isolated domains which decrease in size and increase in surface density with increasing grafting temperature. Domain sizes appeared to correlate with the polarity of the solvent used for imaging. Roughness measurements of the PEG layers were obtained. The results are relevant in relation to the biomedically significant ability of PEG coatings to mask surface features such as charge detected via zeta potential measurements. Copyright 1998 Academic Press.