Research Area

Primer & Chemical Surface Treatment

Ozone Resistance

Aqueous ozone solutions as well as gases containing ozone have a very strong oxidative effect. For determining their effect on materials and components, a test procedure has been developed which can take into account the influence of other substances in addition to ozone. In the test, ozone solutions of up to 5.4 mg/l or an ozone concentration in the gas phase of up to 10,266 ppm can be maintained over longer periods of time by continuous ozone production. If higher concentrations are necessary, these can be achieved by appropriate conversion measures. During testing, the coated sample plates are usually stored half in the liquid and half in the gaseous phase. The effects at the phase interface are of particular interest, since the oxidative attack is most intensive there.

Application Example:

INNOVENT has developed a testing system for resistance investigations against ozone with corresponding parameters. It is used for testing suitable interior protective coatings for ozone reactors, which are applied, e.g. in swimming pools. This testing system is available for further ozone tests under individually adaptable conditions.

    Details of the Test:

    • Test period: approx. 11 days
    • Stress:
      • Lower part of the sample into water containing ozone (approx. 5 mg/L)
      • Upper part of the sample in ozone-containing air (approx. 10,000 ppm)
    • Temperature: 30 °C
    • Continuous supply of ozone-containing air in fine distribution to the aqueous phase

    Test Results:

    • Upper part – after exposure to the gas phase:
      • Thickness decrease: 15 to 23 %
      • Decomposed binder leaves on the surface easily wipeable inorganic pigments
    • Phase boundary – between gas phase and solution:
      • Thickness decrease: 100 %
      • Decomposition down to the substrate surface
      • Rust deposit
    • Lower part – after exposure to the aqueous ozone solution
      • Coating thickness decrease: 4 to 5 %
      • After 5 days clouding of the liquid phase by removed decomposition products
      • Smooth surface

    Further Topics of Corrosion & Resistance

    Dr. Joerg Leuthaeusser

    Head of Department
    Primer and Chemical Surface Treatment

    Phone: +49 3641 2825 48