*2.3. Water Contact Angle Measurements*

Powdered samples of the neat and modified CNCs were pressed in an FT-IR mold to obtain discs (diameter: 1 cm) of smooth surfaces. The water contact angle was determined by placing a water droplet (volume of 15 μL) on each disc surface using OCA20 equipment (DataPhysics Instruments GmbH, Filderstadt, Germany). The standard tangent procedure was used to determine the contact angle. To assure reproducibility, the measurements were performed in triplicate.
