Study on the protective function of cloisite incorporated silane sol–gel coatings cured at different conditions

• Resistance of stainless steel in NaCl solution was improved by silane with cloisite.
• Effect of curing procedure on the performance of silane with cloisite was studied.
• Surface analysis showed the impact of curing condition on coating barrier properties.
• Electrochemical data showed negative effect of overbaking and inadequate curing.
• Correlation between electrochemical noise data and EIS results was assessed.

In this research, cloisite incorporated silane sol–gel coatings cured at different conditions were applied on 304L stainless steel to control its corrosion in 3.5% NaCl solution. At first step, the electrochemical noise data revealed the superior barrier function of the silane coating with cloisite compared to the neat one. As confirmed by the surface analysis, this was attributed to denser structure and increased coating thickness in the presence of cloisite nanoparticles. Then, the study focused on the impact of curing procedure on the performance of the hybrid silane film. The electrochemical data and results of FTIR, water contact angle and FESEM surface analysis showed that the heat treatment at sufficient temperature and time may lead to developing a reticulated coating which functions as an effective barrier to the diffusion of aggressive species.