Comparison of the surface and anticorrosion properties of SiO2 and TiO2 nanoparticle epoxy coatings

Abstract

In this article we compare the morphology, wetting and anticorrosion properties of fluorosilane-modified TiO2, FAS-TiO2/epoxy and SiO2, FAS-SiO2/epoxy coatings. Thirty-nanometre TiO2 and SiO2 nanoparticles were spin coated onto the AISI 316L steel substrate and covered with a thin epoxy layer for nanoparticle fixation. The morphology of the coatings was analysed with SEM imaging and the average surface roughness (Sa), and it showed a homogeneous FAS-TiO2 nanoparticle distribution in the coating, whereas the FAS-SiO2 nanoparticles tended to agglomerate. Static water contact angles were measured to evaluate the wetting properties, indicating the highly hydrophobic nature of both coatings. Potentiodynamic measurements showed that the addition of nanoparticles to the epoxy coating significantly improved the corrosion resistance of the AISI 316L stainless steel. Keywords: TiO2, SiO2, epoxy, coatings, wetting, corrosion V~lanku primerjamo morfologijo, omo~itvene lastnosti in antikorozijske lastnosti s fluorosilanom oble~enih TiO2, FAS-TiO2/ epoksi in SiO2, FAS-SiO2/epoxy prevlek. 30-nm TiO2 in SiO2 nanodelce smo na jekleno podlago tipa AISI 316L nanesli s "spin coaterjem" ter jih prekrili s tanko plastjo epoksidne smole, ki je zagotovila fiksacijo nanodelcev na povr{ini. Morfolo{ke lastnosti prevlek smo analizirali s SEM mikroskopijo ter z meritvami povpre~ne hrapavosti povr{ine (Sa). Pokazali smo, da so FAS-TiO2 nanodelci v prevleki enakomerno razporejeni, medtem, ko FAS-SiO2 nanodelci ka`ejo visoko stopnjo aglomeracije. Omo~itvene lastnosti prevlek smo dolo~ili z meritvami stati~nih kontaktnih kotov, ki so pokazale hidrofobne lastnosti tako FAS-TiO2/epoksi kot tudi FAS-SiO2/epoksi prevlek. Potenciodinamske meritve potrjujejo, da z dodatkom nanodelcev epoksi, za{~itnim prevlekam izrazito izbolj{amo korozijsko obstojnost nerjavnega jekla AISI 316L.

Synthesis of Zinc Oxide Nanomaterials via Sol-Gel Process with Anti-Corrosive Effect for Cu, Al and Zn Metallic Substrates

“…The resulting surfaces exhibited significantly different wetting as a result of the nature of the end group (octyl, glycidyl, octadecyl). The increased hydrophobicity of the coatings from 96 • to ~144 • can be attributed to the more pronounced micro-to nanoparticle-textured surface with a refined roughness structure [47]. The water contact angle values of coatings based on ZnO-TEOS/GPTMS nanoparticles (N2) deposited on Al and Cu were found to be around 100°.…”

“…The resulting surfaces exhibited significantly different wetting as a result of the nature of the end group (octyl, glycidyl, octadecyl). The increased hydrophobicity of the coatings from 96° to ~144° can be attributed to the more pronounced micro-to nanoparticle-textured surface with a refined roughness structure [47]. After deposition on metallic substrates (Al, Cu, Zn), the bonding structure of ZnO-NPs modified with silane precursors was analyzed by FTIR spectroscopy.…”