Fluorine containig plasmas can be used to tailor the wetting properties of a surface to the needs of a particular application.
Hydrophobation of fabrics, nonwovens, and paper
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Water drops on hydrophobic cotton |
Cotton fabric usually absorbs water immediately. Applying a low-pressure plasma
process, the fiber's surface can be altered to make it repell water. After the
treatment, drops run freely over the surface while mechanical properties, the visual
appearance, and the permeability for water vapor remain unchanged. The surface
modification is limited to a very thin layer. A treatment as short as 2 seconds can
be sufficient to achieve this effect in a batch process. Continuous treatments with
a speed of more than 20 m/min are conceivable. The costs of the treatment can be in
the range between 0.15 and 0.75 €/m2. The process is applicable not only
to cotton fabrics but also other fabrics and nonwovens, even paper can be made water
repellant. So far we have experiences in treating materials made from cotton, viscose,
polyesters, and polyamides (linear and aromatic).
Hydrophobic membrane modification
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Representation of membrane stability |
Pervaporation membranes which can remove water from organic solvents degrate during
usage. The deposition of a thin hydrophobic layer made by plasma polymerization of
fluorocarbons can considerably extent the time in which the membrane preserves its
properties. The separation efficiency in not influences at all.
(This project was carried out in colaboration with the GKSS)