The Addition of Silica Nanoparticles with Different Sizes for a Silica Film on Stainless Steel without Crack Formation

摘要

Inorganic protective silica film was tried on the surface of stainless steel using a sol-gel chemical route where tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) were used. In the coating solution silica nanoparticles with different sizes were mixed. Then the film was deposited on the stainless steel substrate. It was intended that by mixing the small and the large particles at the same time a sufficient consolidation of the film was possible because of the high surface activity of the small nanoparticles and a modest silica film would be obtained with a low temperature heat treatment at as low as 200 °C. The prepared film showed enhanced adhesion when compared with a silica film without nanoparticle additions. The films also showed improved protect-ability against corrosion. Scanning electron microscopy (SEM), scratch test, potentiodynamic polarization scan and electrochemical impedance analysis were also used to characterize the films.