Hydrophobic Glasses

There are two categories of what is known in the market as “self-cleaning” glass; two distinctively different approaches to the same problem 

1) Glass coated or applied with hydrophilic layer that uses photo catalytic decomposition
2) Glass coated or applied with a hydrophobic protective coating. 

Glass being a very porous and microscopically rough surface is a magnet to dirt, contamination, bacteria and various other deposits. This, over time, deteriorates the surface, brilliance and clarity of the glass. This is why you will find glasses, in particular those that have been exposed to the elements for a long time, which cannot be cleaned, no matter what cleaning material is used. This happens because the dirt, grime and contamination are so deep and so rooted into the surface of the glass that it cannot be removed. 

To simply explain what these terms actually mean and do and try to point out the important pluses and minuses of each type.

Let’s talk about the two major differences; hydrophilic and hydrophobic. 

The second type of self-cleaning glass above is glass applied with a hydrophobic coating also known as having the “lotus effect” which refers to the very high water repellency exhibited by the leaves of the lotus flower. 

This type of self-clean coating works in fact like a shield. Dirt particles are picked up by water droplets due to the surface created by the hydrophobic coating. This form of glass works in a similar way to "Teflon" works on a frying pan. It produces a non-stick surface and water will run off of this surface quickly and not streak. The coating or applications of this type are silica based and create a Nano scale film that covers the microscopic valleys and peaks on the surface of glass. This type of self-clean coating prevents the contamination, dirt and grime from clinging onto the glass or fixing to the surface. 

The plus points of the hydrophobic type of self-cleaning glass are: That it works on organic and inorganic dirt alike. These type of coatings are scratch resistant and will reduces the need for use of chemicals in any cleaning required as dirt will easily wash off. This coating protects the glass from graffiti and paint. This type of coating can be re-applied on site if required. The hydrophobic coating can be applied on BOTH sides of the glass if required 

Minuses of the hydrophobic type of self-cleaning glass: Products will vary from manufacturer to manufacturer and require professional application. Factory applied coatings, depending on the exact product, have a life span of 3 to 10 years in external conditions. 

Cost wise the hydrophobic coatings and applications are usually about half the cost of the hydrophilic type glasses.