Preparation and Modification of Polydopamine Boron Nitride—Titanium Dioxide Nanohybrid Particles Incorporated into Zinc Phosphating Bath to Enhance Corrosion Performance of Zinc Phosphate-Silane Coated Q235 Steel

Abstract

In this work, PDA@BN-TiO2 nanohybrid particles were incorporated chemically into a zinc-phosphating solution to form a robust, low-temperature phosphate-silane coating on Q235 steel specimens. The morphology and surface modification of the coating was characterized by X-Ray Diffraction (XRD), X-ray Spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and Scanning electron microscopy (SEM). Results demonstrate that the incorporation of PDA@BN-TiO2 nanohybrids produced a higher number of nucleation sites and reduced grain size with a denser, more robust, and more corrosion-resistant phosphate coating compared to pure coating. The coating weight results showed that the PBT-0.3 sample achieved the densest and most uniform coating (38.2 g/m2). The potentiodynamic polarization results showed that the PDA@BN-TiO2 nanohybrid particles increased phosphate-silane films’ homogeneity and anti-corrosive capabilities. The 0.3 g/L sample exhibits the best performance with an electric current density of 1.95 × 10−5 A/cm2, an order of magnitude lower than that of the pure coatings. Electrochemical impedance spectroscopy revealed that PDA@BN-TiO2 nanohybrids provided the greatest corrosion resistance compared to pure coatings. The corrosion time for copper sulfate in samples containing PDA@BN/TiO2 prolonged to 285 s, a significantly higher amount of time than the corrosion time found in pure samples.

Effect of Calcination Temperature on Phase, Morphology, and Optical Properties of TiO2 Nanoparticles and Boron Nitride Decorated TiO2 Nanotubes

“…Within the 500 cm −1 to 750 cm −1 range, attention was given to the absorption band, indicating the TiO 2 lattice bonds' (O−Ti−O) bending vibrations, confirming the TiO 2 crystalline phase. 17 Sharp peaks between 1500 cm −1 and 1700 cm −1 were identified as characteristic OH group bending vibrations. Furthermore, the observed absorption peaks ranging from 2500 cm −1 to 3000 cm −1 were associated with the interaction with hydroxyl (OH) groups of water (H 2 O) molecules.…”

“…Figure a displays the FTIR spectra of TiO 2 samples, covering temperatures from 530 °C to 1000 °C. Within the 500 cm –1 to 750 cm –1 range, attention was given to the absorption band, indicating the TiO 2 lattice bonds’ (O–Ti–O) bending vibrations, confirming the TiO 2 crystalline phase . Sharp peaks between 1500 cm –1 and 1700 cm –1 were identified as characteristic OH group bending vibrations.…”

Effect of Temperature on the Morphology and Corrosion Resistance of Modified Boron Nitride Nanosheets Incorporated into Steel Phosphate Coating

“…Upon immersion of the specimen in the solution containing 12% Na 2 EDTA, 4% triethanolamine, and 9% NaOH at a temperature of 70 • C for 5 min, the coating was dissolved entirely, exposing the underlying steel substrate. The processes of pre-dissolving and post-dissolving of steel specimens, denoted as W1 and W2, respectively, were accompanied by a mass measurement [25].…”