The surface wettability of copolymers was determined by measuring the water contact angle using a Krüss DSA 100 Drop Shape Analyser goniometer. The measurement was according to according to European Standard EN 828. The samples were prepared as dried films with a clean surface. A droplet of 2 µL of ultrapure deionised water was slowly dripped onto the surface of the sample, and after 1 min, a picture of the sessile drop was photographed using a macro lens. The contact angle was calculated by measuring 2 angles (left and right) from 5 separate sessile drops for each material.