How can wettability be increased in fluoro-silicone/acrylate materials?

How can wettability be increased in fluoro-silicone/acrylate materials?

• A. Incorporation of HEMA
• B. Increasing fluorination of the polymer
• C. Adding titanium dioxide particles
• D. Roughening the surface to create microtexture

Answer: (A)

Wettability depends on surface energy and how water can interact with the surface. Fluoro-silicone/acrylate polymers are highly hydrophobic because fluorinated groups lower surface energy, so water beads up and wets poorly. Introducing HEMA brings hydrophilic hydroxyl groups into the polymer. These polar sites increase the surface energy and enable stronger hydrogen bonding with water, allowing water to spread more readily across the surface. That higher affinity for water lowers the contact angle and improves wettability, which is desirable for tear film spreading on contact lenses. Adding fluorination would do the opposite by making the surface even more hydrophobic, so wettability would decrease. Titanium dioxide particles could affect roughness and optical properties but don’t reliably enhance wettability in this context. Roughening the surface can trap air on a hydrophobic fluoro-silicone, often increasing the apparent contact angle rather than improving wetting.

Wettability depends on surface energy and how water can interact with the surface. Fluoro-silicone/acrylate polymers are highly hydrophobic because fluorinated groups lower surface energy, so water beads up and wets poorly.

Introducing HEMA brings hydrophilic hydroxyl groups into the polymer. These polar sites increase the surface energy and enable stronger hydrogen bonding with water, allowing water to spread more readily across the surface. That higher affinity for water lowers the contact angle and improves wettability, which is desirable for tear film spreading on contact lenses.

Adding fluorination would do the opposite by making the surface even more hydrophobic, so wettability would decrease. Titanium dioxide particles could affect roughness and optical properties but don’t reliably enhance wettability in this context. Roughening the surface can trap air on a hydrophobic fluoro-silicone, often increasing the apparent contact angle rather than improving wetting.