Study on Pretain CleanCoat

Benefits of Pretain’s CleanCoat™ (by Prof. Dr. Jeremy Ramsden)

The nanoparticles adhere extremely strongly to their substrate and cannot be detached. Unless it is subjected to abrasion, the coating remains active indefinitely. On abraded surfaces, depending on the intensity of wear, the coating may need to be renewed (for example, a floor coating may need to be recoated every two years). Pretain’s CleanCoat™ can be durably applied to a large variety of materials, including steel, glass, plastics, concrete, wood, paper and textiles.

The spray technology enables surfaces of arbitrary and complicated shapes (such as window blinds, curtains, light fittings and all the equipment found in an operating theatre) to be coated. The coating is extremely thin (less than 1 μm).
Nano-engineering of the basic titanium dioxide unit confers visible light adsorption onto the material.

An additional feature of Pretain’s CleanCoat™ is that it retains its photocatalytic (sterilizing) effect in the dark. This is due to the fact that oxidizing and reducing species (e.g., the oxygen and hydroxyl radicals mentioned above) can be stored for long periods on the surface of the particles after illumination ceases.

A further benefit is that experience shows that the nanoparticles acquire a weak net negative charge upon illumination. Since dust particles are also typically negatively charged, they are electrostatically repelled from the coated surfaces, and this repulsion suffices to keep them dust-free.

It should perhaps be pointed out that there are a number of companies offering titanium dioxide wall coatings but, as far as can be ascertained, Pretain CleanCoat is the only product that has comprehensively overcome the various technical obstacles mentioned.


Pretain’s CleanCoat™ coated hospital interiors provide better hygiene than traditional cleaning régimes at lower cost. Since it is a permanently active coating, surfaces do not require any further cleaning after having been coated. Although the main interest is of course in microbiological decontamination, odors are also effectively removed.

The technology is equally applicable to other environments in which the elimination of airborne microbes is beneficial, including schools and transportation vehicles such as aircraft, railway trains and taxicabs.