Wettability control of modified stainless steel surfaces for oxide catalyst carrier slurry coating

Micrometer sized FeAl particles were added on 304 stainless steel surfaces to prepare rough surfaces with irregular patterns to make the surface super hydrophilic in order to effectively coat catalyst carrier alumina slurry on them. This method was compared with other conventional methods as follows. Micromachining and acid etching were firstly tried to prepare regular patterned surfaces with square micropillar arrays. Sand blasting was then tried to create micro roughness of the surface by removing materials from the surface. These methods were not so successful with contact angles higher than 50° for concentrated alumina slurry on the treated surfaces. In contrast to this, micrometer sized FeAl particles added 304 stainless steel surfaces showed excellent wettability with contact angles as low as 15° for concentrated alumina slurry on the treated surface. It was also observed that FeAl treated stainless steel surfaces were stable up to 700°C, indicating good adhesion between the catalyst support substrate and catalyst carrier layer at high temperatures.