Nanoparticles incorporated in silane sol–gel coatings
Concentration of silane precursor is another key factor influencing on the correction protection properties of the silane films. Effects of silane concentration on the thickness of BTSE silane fresh and cured films are presented in Fig. 23.7.
According to Fig. 23.7, increase of the silane concentration led to an increase in the thickness of silane film in both the fresh film and the cured ones applied on Al 1050 substrate [21]. According to the EIS results of the coatings immersed in 0.39 M Na2SO4 for 2 h (Fig. 23.8), increase of the bath concentration provided more protective performance for the cured silane films due to prolonging the conductive pathways as a result of formation of thicker film [21]. In the most cases, increasing in the bath concentration may lead to a thicker but porous film with higher probability of microcracks formation