A02-12 SOIL RESISTANT AND SELF-CLEANING SURFACES OF STAINLESS STEEL WITH NEW SOL-GEL AND ALD COATINGS R. Mahlberg 1 , J. Mannila 1 , J. Romu 2 , J. Nikkola 1 , R. Ilola 2 , O. Söderberg 2 , J. Koskinen 1 , S-P. Hannula 1,2 , A. Mahiout 1 1 VTT Technical Research Centre of Finland, Finland, 2 Helsinki University of Technology, Finland Abstract Corrosion, fouling and wearing of metal surfaces are the most common problems that are faced in industry as well as in environmental use. In particular, the maintenance of metal products and also the decrease in their value in use can cause major financial losses for example in construction, transportation, process and food industry. Different coatings or surface treatments have been used to enhance the protection properties of metal surfaces. Especially during the last ten years there has been a general interest to study the potential of nanoscale inorganic-organic hybrid sol-gel coatings and ALD coatings to improve the properties of metal surfaces. Typically, sol-gel and ALD coatings are thin, ranging from nanometer scale to several micrometers. Sol-gel coatings are usually optically transparent reminding of very thin layers of varnish or lacquer. The main difference is that the sol-gel coatings consist of an inorganic network, which forms the backbone of the coating. In hybrid sol-gel-coatings, the amount of the organic constituent can be varied according to the application. By changing the organic and inorganic counterparts and varying their amounts, the properties of the coatings can be modified in a wide scale. TiO 2 -based or -doped coatings can be photocatalytically active and have self-cleaning properties under UV irradiation. This paper shows how the quality of metal products is improved by applying new thin coatings prepared with ALD or sol-gel techniques. TiO 2 -modified sol-gel and ALD coatings were used on stainless steel substrates (EN 1.4301 (AISI 304)) with the dry-brushed (2J) surface finish to enhance the soil resistance and cleanliness level of the material. Introduction Stainless steels/Metals are increasingly applied in construction and different process applica- tions. However, the performance and appearance of metal surfaces are often impaired by corrosion, fouling and wear. Environmental factors such as moisture combined with salts, acidic substances or other impurities and dirt particles are responsible for the wear and corrosion of metal surfaces in outdoor use. Fingerprints on metal surfaces of interior products are an annoyance and may generate corrosion/wear as such or indirectly as a result of frequent harsh cleaning (strong chemicals, rubbing). Recently, stainless steel has gained popularity as decorative elements in household applications and in public buildings. This has urged the need for finding easy-to-clean or self-cleaning coatings for these surfaces. The photocatalytic titanium dioxide (TiO 2 ) was introduced as a powerful agent in self-cleaning applications already in the early 1970’s [1]. When TiO 2 is exposed to UV light, holes (h + ), hydroxyl radicals (OH - ), electrons and superoxide ions (O 2 - ) are formed which result in oxidation reactions and decomposition of organic compounds. The photocatalytic reactions on 101