*2.7. Surface Wettability Characterisation*

Three 1 mL Hamilton 1000 series syringes, containing DIW of pH 4, 7, and 9, were adjusted to a Dataphysics SHD syringe temperature controller (Reno, NV, USA), which is integrated with the Dataphysics OCA 100 automatic multi-liquid dispenser contact angle goniometer device (San Jose, CA, USA). This was done in order to increase/decrease the liquid temperature inside the syringes, while being monitored. The surface wettability of the coated and uncoated stainless steel 316L samples was measured using the Sessile drop method [36]. This was done by dispersing a 5 μL droplet (5 μL/s dosing rate) on the examined surface then capturing its image, at static condition, which is analysed afterwards through the device provided software SCA 20 to obtain the liquid – surface CA. The CA measurements were conducted three times, for the three types of liquids, at a fixed liquid temperature of 20 ◦C to 60 ◦C, with a ±0.1◦ contact angle precision.
