Modeling of PEG grafting and prediction of interfacial force profile using X-ray photoelectron spectroscopy

Poly(ethylene glycol) (PEG)-grafted Sephadex (TM) derivatives were prepared by a covalent amine conjugation method and characterized using XPS. PEG-grafting kinetics were studied using both Langmuir and Langmuir-Freundlich isotherm models by correlating fractional C-O intensities obtained from high-resolution C 1s scans with the grafting period. Theoretical values were compared with experimental results to confirm the reliability of the modeling predictions. Detailed surface characterization of PEG-grafted Sephadex derivatives was performed using XPS data, and the results were used to predict the interaction free energy and stick force exerted at the matrix interface. Copyright (C) 2011 John Wiley & Sons, Ltd.