Fig. 6. High resolution X-ray photoelectron spectra and sessile drop contact angles recorded for PCysMA brushes of approximately 10 nm dry brush thickness following surface chemical reactions. (a) N 1s spectrum of PCysMA after incubation with excess glutaraldehyde in THF. (b) N 1s spectrum of an as-prepared PCysMA brush. (c) F 1s spectrum recorded after incubation of a PCysMA brush with (i) excess glutaraldehyde in THF followed by (ii) exposure to gaseous trifluoroethylamine, TFEA, for 2.5 h at 22 °C. (d) F 1s spectrum of the same PCysMA brush after exposure to TFEA for 2.5 h at 22 °C but with no prior exposure to glutaraldehyde. (e) F 1s spectrum of an as-prepared PCysMA brush.