*2.2. Photochemical Crosslinking*/*Grafting*

HEMA (4.8 g, 37 mmol), Irgacure 651 (0.024 g, 0.085 mmol), EGDMA, and PEGMA at di fferent molar ratios (Table 1) were placed into Schlenk flasks; deionized water (80 wt% with respect to HEMA) was used as solvent, and oxygen was displaced by bubbling argon for 6 min. In order to obtain homogeneous solutions, the solutions were sonicated using an ultrasonic bath Branson 2800 (Branson Ultrasonics, Danbury, CT, USA) for 5 min; afterwards, samples of PET fabric were introduced in the Schlenk flasks. Oxygen was thoroughly displaced by using three freeze-thaw cycles using a dry ice/acetone bath and argon flow. Afterwards, the flasks, filled with argon, were sealed, and stored for 12 h inside a refrigerator in order to allow the swelling of the fabric.


**Table 1.** Surface modification of polyethyleneterephtalate (PET) fabric with hydrogel using the photochemical method (λ = 350 nm); water was used as solvent.

1 With respect to HEMA monomer; 2 calculated using the Equation (1); 3 calculated using the Equation (2).

Then, the fabrics were removed from the soaking solution and were placed between two glass plates of 10 cm × 10 cm, sealed with a silicone spacer (1 mm thickness), and the samples were irradiated using lamps of wavelength of 350 nm for 30 min inside a RMR 200 Rayonet Photochemical Chamber Reactor (Palisades Park, NJ, USA) under argon atmosphere. Residual monomers and other compounds

were extracted by washing with successive ethanol/water mixtures with increasing ratio of deionized water; finally, the samples were dried under vacuum until constant weight.
