Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Coating of stainless steel surfaces by ultra thin and coherent silica, titania and mixed silica-titania coatings, to improve their anti-fouling characteristics

Coating of commercial stainless steel surfaces (finish 2R and 2B), employed in the manufacture of heat exchangers, has been achieved by ultra thin (sub-micron thickness) layers, using a sol-gel technique.

Defect-free silica coatings have been obtained with two notable characteristics:
- hardness greater than that of the stainless steel substrate.
- reduced surface roughness compared to the (bare) substrate.

Titania films were also obtained by the same techniques. A promising procedure for obtaining mixed particulate/sol-gel titania coatings were developed in order to cope with film cracking. Although film cracking was not completely eliminated, employing stable concentrated dispersions of titania nanoparticles drastically reduced it. The knowledge gained in the preparation of these nanoparticles, sols and coatings is considered useful in future endeavors of producing particles and modified surfaces with improved properties.

Using equipment developed at CPERI, coatings were produced on medium size surfaces and heat exchanger plates (e.g. 15x35cm) as well as in tubes 50cm in length. Coating of larger surfaces and of longer tubes does not appear to be a difficult task. The coating technique, demonstrated at laboratory scale, is relatively inexpensive and reliable.

Informazioni correlate

Reported by

Centre for research and technology Hellas - CERTH
6th km. Charilaou – Thermi Road
57001 Thermi, Thessaloniki