Hydrophobic Plasma Treatment

Hydrophobic plasma coatings are a sub-category of plasma surface functionalisation, the specific precursor being chosen to produce a permanent, low surface energy layer on the material or part being treated. The hydrophobic surface is typically less than 1/100th thickness of a human hair, colourless, odourless and doesn’t affect the look or feel of the material in any way.

Permanent hydrophobic surfaces are rapidly finding new applications all the time. Liquid repellent coatings currently enhance products in the textile, medical device, ophthalmic and consumer electronics industries to name but a few.

In plasma coating, a nano-scale polymer layer is formed over the entire surface area of an object placed in the plasma. The coating process takes just a few minutes. The coating produced is typically less than 1/100th thickness of a human hair, colourless, odourless and doesn’t affect the look or feel of the material in any way. It is a permanent coating too, being bound to the material surface on an atomic scale.

Plasma coatings are one of the most exciting areas of plasma technology, offering enormous potential to enhance a material’s function and value over a wide range of applications. They deliver two main categories of surface property: totally liquid (water & oil) repellent, or totally wettable.

Liquid Repellent Plasma Coatings

Specific treatments render surfaces totally repellent to water, solvents and oils as shown below in the example of cotton that has been plasma coated.

Untreated Surface
Plasma Treated Surface

How Plasma Coatings Work:

Monomers are introduced with the plasma feed gas. Monomers are small molecules which will, under the correct conditions, bond together to form polymers. Plasmas create the right conditions at the surface of the material for this to happen both quickly and efficiently. Different monomers are used to produce hydrophobic and hydrophilic surfaces.