SEM

Cross-section of PET samples grafted with PHEMA and poly(HEMA-co-PEGMA) using UV method and gamma irradiation were analyzed by SEM and their thicknesses were measured. Samples modified by using the UV method with PHEMA showed a hydrogel cover of roughly 50 μm and the sample modified with poly(HEMA-co-PEGMA) (95:5%) using the same method had a cover of roughly 60 μm (Figure 6a,b). Samples grafted using gamma irradiation with PHEMA showed a thick cover of around 450 μm and of 600 μm for a sample with poly(HEMA-co-PEGMA) (90:10%) (Figure 6c,d).

**Figure 6.** SEM images of (**a**) UV PET100:0:0.5, (**b**) UV PET95:5:0.5, (**c**) γ60 PET100:0:50, and (**d**) γ60 PET90:10:30.

Diameters of individual fabric fibers were also measured obtaining mean thickness of roughly 15.0 μm for pristine fibers and of 15.2 μm and 15.0 μm for samples modified by UV method with PHEMA and poly(HEMA-co-PEGMA) (95:5%) respectively (Figure 7), these constant diameters indicated that there was only a surface grafting of the hydrogel. On the other side, by gamma irradiation, an increase in thickness of fibers was observed; for example, the single fibers of the PET sample grafted with PHEMA had diameters around 21 μm; these results indicated that grafting was also performed inside of the fibers [41]. Also, a clear change on fabric fibers surface was observed (Figure 7e) when gamma irradiation was used.

**Figure 7.** SEM images of fiber PET-fabric: (**a**) Unmodified PET, (**b**) and (**c**) UV PET95:5:0.5, (**d**) and (**e**) γ60 PET100:0:50, (**f**) γ60 PET90:10:30.
