## 3 Results
### Wetting Resistance of the Coating  
Table 5 shows the water contact angle of the membranes coated in this study. The uncoated membrane has a hydrophilic water contact angle of 27\({}^{\circ}\). After the application of the coatings, surface 1 is hydrophobic and has a water contact angle of at least 100\({}^{\circ}\), confirming the hydrophobic character of the coatings. Without organic crosslinking agent (PFD solution only), the highest water contact angle of 117\({}^{\circ}\) for 5 wt. % solution (membrane 1) and 118\({}^{\circ}\) for a 10 wt. % solution (membrane 2) are achieved. This difference in water contact angle is statistically insignificant and therefore, the contact angle is considered to be independent of the concentration in the range from 5 and 10 wt. % for this system. When adding components with polymerizable functionalities to form the polymeric network, the fluorinated fraction decreases (membranes 3-5). This is visualized in a slightly reduced hydrophobicity on the coated surface compared to membrane 1 and 2, with a water contact angle ranging from 100\({}^{\circ}\) to 110\({}^{\circ}\). For the Ak/T/D/BTFO2N system (3 and 4), the water contact angle is increased from 100\({}^{\circ}\) to 110\({}^{\circ}\) using a 5 and 30 wt. % solution respectively. The V/Mc/F13 system (5) achieves a water contact angle of 109\({}^{\circ}\) with a concentration of only 5 wt. % and including a polymeric network. The water contact angle of untreated surface 2 equals 28\({}^{\circ}\) after 0.5 s, whereas after the coating procedure the water contact angle after 0.5 s varies from 83\({}^{\circ}\) to 100\({}^{\circ}\) for membrane 1-4. For these membranes, the water contact angle continuously decreases over time. For membrane 1-3 the droplet disperses in the membrane only after 2 min. For membrane 4, the droplet sinks into the membrane within 2 min of contact time. For membrane 5, the uncoated side even shows a stable contact angle of 110\({}^{\circ}\) similar to the contact angle on the coated side. These observations show that the surface hydrophobicity on the uncoated side is also affected by the coating process, indicating that a part of the coating is able to pass through the entire membrane cross-section and is also applied (partially) on the uncoated side of the membrane. However, despite the increase in water contact angle, the membranes 1-4 are still wetted in membrane distillation and are considered as hydrophobic/hydrophilic membranes. Membrane 5 is considered as an entirely hydrophobic membrane. The measured liquid entry pressure for the different membranes varies from 1.6 to 3.5 bar, with a large variation for multiple measurements of the same membrane. This variation in liquid entry pressure is attributed to the inhomogeneity of the coatings, meaning that the coating is not applied equally on the entire membrane surface on some parts of the surface are not sufficiently hydrophobic. This becomes visible after submerging the membranes in water. While most regions are not wetted, some areas of the membrane surface are wetted, showing that the bar coater and the roll-to-roll system are not the preferred application methods when applying the coatings on porous membranes. The contact angles reported in Table 5 only consider the area of the membrane that was not wetted after submersion of the membrane in water. However, the inhomogeneous application of the coating with barocaoter or the roll-to-roll system was also visible in the large spreading of the contact angle measurements of 20\({}^{\circ}\) when measuring at random spots on the membrane.