The benefits of hydrophobic coating that you have to know!

Water is one of the essential resources for our daily lives. However, as a general rule, electronic devices  should be protected from water exposure, so be sure to check if there is water around the devices before using them. In this article, we will be explaining the principles and applications of hydrophobic coating!

What is hydrophobic coatings (durable water repellentcoatings)?

Hydrophobic coating or DWR is a surface treatment that often being applied to glass substrates to create a water and oil repellency. By applying a <20nm Nano-coating on a lens surface to fill the voids , it prevents dirt from adhering. Anti-fingerprint (AF)/hydrophobic coating feature high transparency and will not change the optical performance after coating process.

Two benefits of hydrophobic coating

Almost no water stains left on surfaces

The principle of hydrophobicity is applying hydrophobic coating to fill the voids on surfaces of glass substrates, causing water to bead up when dropped onto the surfaces without leaving water stains. Anti-fingerprint (AF)/hydrophobic coating promote self-cleaning effects. It creates dirt and dust repellent characteristics due to voids filling during the coating process.
 

Anti-fingerprint (AF)/durable water-repellent characteristics

Hydrophobic coating or DWR is a surface treatment that often being applied to glass substrates to create a water and oil repellency. Since it fills voids and grooves on surfaces of substrates, it creates dirt and dust repellent characteristics and gives good anti-fingerprint features. One of the benefits of hydrophobic coating is that it develops a self-cleaning effect so both water and oil will be beaded up and rolled off on the surfaces. More, it has excellent water-repellent and anti-fouling properties so oil-based marker stains, fingerprints, and water stains can be wipe off easily.

Applications of Hydrophobic coatings

Hydrophobic coating(hydrophobic) application-Example 1

Hydrophobic coating is often applied to electrical products used in daily life. It improves the durability of electrical products by protecting internal parts from liquid damages. Besides, it can also help protect electrical products from moisture, dust, static electricity, and deterioration.
 

Hydrophobic coating(hydrophobic) application-Example 2

In addition to electrical products, hydrophobic coating is applied to silicone rubber products, automotive products, wearable devices, military products, etc. Materials such as glass, metals, plastics, resins, and wafers can be treated with  hydrophobic coating finishing. Conducting hydrophobic coating via vacuum deposition not only improves the durability of the devices, but also protects them from corrosion and salt damage.

What is salt damage?
A marine atmosphere is laden with salt of sea mist carried by the wind while the sea mist will be scattered and lifted by updrafts to an altitude of more than 2,000 meters.

The different between hydrophobic coating and hydrophilic coating

When water drops on surfaces that treated with hydrophilic finishing, it stays on the surfaces so the surfaces will get stained easily and require frequent cleaning. On the contrary, when water drops on surfaces that treated with hydrophobic finishing, it will bead up and flow away quickly, leaving the surfaces dry and without any stains.

How to tell the difference between the two? The definition is that a surface should be super hydrophilic when its contact angle θ is <10° while a surface should be hydrophilic when its contact angle θ is between 10° to 90°. On the other hand, a surface should be hydrophobic when its contact angle θ is between 90° to 120°while a surface should be super hydrophobic when its contact angle θ is > 120°.
 

Yang-En Tech’s Anti-fingerprint coatings

We prepare anti-fingerprint coatings via  vacuum coating instead of a one-step spraying method. Via vacuum coating , the coating 
film will be formed more evenly and will have no impacts on transmittance. Except for anti-fingerprint properties, the coatings have good anti-fouling, dust-proof, water-repellent, oil-proof, anti-oxidation, and anti-corrosion properties and can be applied to materials including glass, plastics or metals.
 

Hydrophobic Coating Case 1 - Vacuum coating

Generating a layer of hydrophobic coating on the glass surface via vacuum coating, with the increase of contact angle, water will flow away easily. After water-repellent coatings, the surface becomes smoother, more resistant to scratches, and has excellent durability. It is also possible to coat substrates other than glass substrates. After durable  water-repellent coatings, the surface has a relatively low coefficient of friction and a contact angle of >110°, preventing dust and dirt from adhering.

Hydrophobic coatings case 2 – Spraying

The other way to conduct hydrophobic coating is via spraying. It can be applied evenly to the surface of substrates such as glass, acrylic, and PC via spraying. Before applying water repellent spray, the first is to clean the surface of substrate. Then, sweep the spray from side to side, evenly covering the surface . After drying, a hydrophobic coating film is formed and exhibits water-repellent properties. The disadvantage is that the water-repellent effect decreases over time, so vacuum coating is more recommended.

Conclusion

Hydrophobic coatings are used in everyday life and technology applications. YANG EN TECH CO., LTD. have over 15 years of experience in providing services including optical coating designs, optical filter manufacturing, glass processing/finishing, and all kinds of optical coatings. Should you have any requests for hydrophobic coatings, please do not hesitate to contact us!