Test for Hydrophobic Contamination on Glass

Test for Hydrophobic Contamination on Glass

With the help of contact angle measurements, this test procedure can identify hydrophobic contamination on glass surfaces. The test will be able to recognise monomolecular layers of hydrophobic organic contaminants in fractions when it is carried out properly. Surfaces that are extremely porous or rough may considerably reduce the test’s sensitivity.

To measure the advancing contact angle in this test, droplets of permanganate-distilled water are applied to the glass surface and use a mounted hypodermic syringe. Either a sessile drop is observed under a comparator microscope with a goniometer scale to determine the contact angle or a sessile drop is photographed and the angle is determined using a protractor.

Surfaces with organic contamination have contact angles that are greater than those on clean surfaces, which are close to zero. If the surface is rough and/or porous, or if it contains  hydrophilic materials, the sensitivity of the test declines.

This standard does not guarantee that using it will eliminate all or even most safety concerns. The user of this standard is responsible for establishing suitable safety and health procedures and determining whether any regulatory restrictions apply before use.

Video 01: How to Evaluate Hydrophobic Protective Glass Coatings

Conclusion:

The test for hydrophobic contamination on glass is a simple and effective method for detecting the presence of hydrophobic coatings on glass surfaces. The test involves placing a drop of water on the glass surface and observing the behavior of the droplet. If the droplet beads up and rolls off the surface, this indicates the presence of a hydrophobic coating, whereas if the droplet spreads out and wets the surface, this indicates the absence of a hydrophobic coating.