Sub-micrometer-thick hydrophobic zeolite corrosion-resistant coatings synthesized using solvothermal secondary growth†

Solvothermal secondary growth was used to fabricate zeolite MFI anti-corrosion coatings on a stainless steel plate. Four different diols, i.e., ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol, were each investigated as a synthesis solvent. High-quality b-oriented MFI films each with a thickness of 400–500 nm were obtained. The evolution processes and the corresponding characteristics of the zeolite films were compared. FT-IR and XPS analysis of the zeolite surface functional groups demonstrated that the film hydrophobicity mainly originated from the reaction between the diol solvent and the hydrolyzed silica source. The uniform structure and the surface hydrophobicity of the resulting MFI coatings were found to offer good corrosion protection for stainless steel materials.