Fig. 2.

Chemical characterization of PEA treated surfaces. After plasma polymerization, the chemical signature of PEA was confirmed on both Thermanox and glass coverslips [13,26]. (A) and (B), the chemical composition of the surface measured by XPS analysis. The spectra from left to right were carbon, oxygen and wide scan respectively for PEA-treated Thermonox (A) and glass coverslips (B). In the carbon spectra, the presence of a large peak corresponding to C–C bonds found at 284.9 ​eV (C1) was used as a reference and used to identify peaks at 285.1 ​eV (C2), 286.2 ​eV (C3), 288.5 ​eV (C4) which correspond to the C–C–C bonds, C–O bonds, and C O bonds respectively. In the Oxygen spectra, the peaks corresponding to the C O and C–O–C bonds were found at 531.5 ​eV (O1) and 533.2 ​eV (O2) respectively. The red line corresponds to the overall fitting peak, and the lines with other colours correspond to the individual deconvoluted peaks representing the different functional groups. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)