962376.fig.003a
(a)
962376.fig.003b
(b)
962376.fig.003c
(c)
962376.fig.003d
(d)
962376.fig.003e
(e)
962376.fig.003f
(f)
Figure 3: XPS high-resolution C1s scans of aminated glass (a) before and (b-e) after star PEG grafting at various coupling concentrations (0.55, 1.66, 5, and 15% w/v). Note that the relative intensity of the C–O peak increased with the PEG coupling concentration; (f) Overlay spectra of 15% PEG-modified on unmodified aminated surface.