CA and SFE of hydrogels treated with various gaseous plasmas.

Parameters	Hydrogels
	HG@UT	HG@Ar	HG@O2	HG@Ar + O2
Contact angle (°)
Water	60.32 ± 0.02	40.22 ± 0.59	30.90 ± 0.23	18.58 ± 0.91
Ethylene glycol	30.50 ± 1.45	21.53 ± 0.97	19.56 ± 0.87	17.01 ± 1.76
Surface free energy (mJ m −2 )
Dispersive (γd)	20.43 ± 1.10	7.94 ± 0.46	4.44 ± 0.26	2.09 ± 0.27
Polar (γp)	21.77 ± 0.74	51.08 ± 1.16	65.50 ± 0.61	80.75 ± 1.37
Total (γtotal)	42.20 ± 0.36	59.02 ± 0.73	69.94 ± 0.36	82.84 ± 1.12