Figure 9

AFM imaging of PET fiber topography and roughness for fiber surfaces treated by SFR and PNaSS grafting protocols after different aging times (shown above each column); Grafting conditions: PET samples subject to SFR and then PNaSS functionalization protocols of ozonation for 10 min at 30 °C and grafting for 1 h at 45 °C. AFM scan area: 1.5 μm × 1.5 μm (0.5 Hz) in air at 25 °C (n = 3).