Hydrophobicity Print E-mail

Hydrophobicity, from the Greek words hydro=water and phobos=fear, is the concept of how certain molecules are repelled by water. As water consists of polar molecules (H2O), hydrophobic molecules tend to be non-polar. Lipids like fats, waxes, and vitamins are well-known hydrophobic substances.


The most common measurement for the hydrophobicity of a surface (repellency of a surface against water) which can also be calculated mathematically is the contact angle θ of a drop of water (with a pre-defined diameter) at the three phase boundary where the liquid, gas, and solid intersect. The higher the hydrophobicity of a surface, the higher the contact angle will be of a drop of water on that surface.


Usually, the contact angle of a drop of water on normal glass surfaces is around 20-30°. Surfaces are called hydrophobic if the contact angle of a drop of water is higher than 85°. Surfaces are called superhydrophobic if the contact angle is higher than 150° (allowing the water drop to form an almost perfect sphere).


hydrophobe-1 hydrophobe-2 hydrophobe-3

Contact angle θ = 25°
(normal glass)

Contact angle θ = 85°
(Ultraclean Glass™ after 10+ years of simulated wear)

Contact angle θ = 110°
(new Ultraclean Glass™)



Glass and porcelain surfaces treated with our Ultraclean Glass™ / Porcelain™ CONVERTER chemical display a contact angle of about 110° after application with an extremely high durability (see also our section on Durability).

Tests show that Ultraclean Glass™ / Ultraclean Porcelain™ remains hydrophobic even after 40,000 double-abrasion washing cycles with a hard brush (translating to a high-performance lifetime of at least 5 years under normal conditions). Ultraclean Glass™ will always be more hydrophobic than normal glass, even after decades of normal use, however the performance may eventually reduce (if the EVERSHIELD Lifetime Protection after-care program is not used).

Prev Next


Ultrashield Corporation are the first manufacturer to offer a genuine lifetime performance guarantee for glass converted by a certified applicator and used in conjunction with the after-care program. Get the Facts...


Ultraclean Glass™ is as durable as normal glass and the effect can only be removed through physically damaging the glass surface. Get the Facts...


Currently the only practical and cost-effective way to achieve a self-organising hydrophobic layer one molecule thick with chemicals is through the sol-gel process. Get the Facts...


Covalent bonding between (silicon dioxide) glass molecules and the converter chemicals can only be achieved with a nano-scale product one molecule thick, incorporating bonding and functional (repellent) components. Get the Facts...


Currently only products utilising strong covalent bonding with the glass can achieve such industrial quality durability and performance. Get the Facts...


Abrasion testing is an industry-standard method for evaluating durability used in the coatings industry worldwide. Washability testing involves adding water or cleaning chemicals during abrasion testing, which closely mimics the normal cleaning process used to remove limescale from shower glass. Get the Facts...


Ultraclean Glass™ CONVERTER offers up to 100 times the durability of traditional silicone and fluorocarbon-based coating technologies in abrasion/washability testing. Get the Facts...

Ultrashield Newsletter

Our newsletter gives valueable information on the glass industry and easy clean products

Copyright © 2010-2013 Ultrashield Limited. All Rights Reserved.