Antifog

from Wikipedia, the free encyclopedia

An anti-fog coating is a special surface treatment on crystal-clear surfaces that is intended to prevent fogging (condensation) under the action of water vapor ( fog ). Three different types of coatings are used: wetting agents, nanoparticles and saliva.

Wetting agents

Antifog (anti-fogging) coatings have been known for a number of years from the applications for transparent visors for motorcycle helmets, protective goggles or swimming goggles. Special sprays or liquids are used, so-called wetting agents , which prevent microscopic droplets from forming when water vapor condenses, which scatter the light and make the clear parts almost or completely opaque. A disadvantage is the limited smear or scratch resistance of these substances, which require frequent after-treatment.

Nanoparticles

Michael Rubner from the Massachusetts Institute of Technology (MIT) developed a permanently effective coating with an anti-fog effect based on nanotechnology in 2005 . Silica - nanoparticles are in a polymer film embedded, which is applied to the surfaces to be treated according to a special procedure. The water vapor is also deposited on these layers as a clear and transparent film. The layer is almost maintenance-free and also not very sensitive mechanically.

The anti-fog coating is a clear, transparent layer with a thickness of a few micrometers that does not significantly change the optical properties of the transparent object treated.

The nano-antifog coatings are used for the above-mentioned applications and also for anti-fogging properties on automobile windscreens, headlight glazing and in aircraft construction, in optical devices and in viewing windows for monitoring purposes in industrial plants. Far larger areas can be treated evenly than with conventional sprays.

Due to the wide range of applications, these coatings are also offered at low prices in the sports and leisure sector.

saliva

In recreational diving, saliva is rubbed into the diving mask from the inside for the same purpose in order to avoid fogging.

literature

  • Robert Nabenhauer: packaging dictionary . Technical terms and application examples explained by experts, 2nd edition, 2010.

Web links