Optimization of silane sol-gel coatings for the protection of aluminium components of heat exchangers

Silane coatings modified with hydroxyapatite nanoparticles to enhance the biocompatibility and corrosion resistance of a magnesium alloy

The fast corrosion rate of magnesium alloys has restricted their use as biodegradable implants. Hence developing a practical approach to retard the corrosion rate of the AZ31 magnesium alloy, as well as promoting cell adhesion and proliferation is of great importance. Silane coatings were applied through dip coating, on samples pretreated in hydrofluoric acid. Samples were immersed in simulated body fluid at 37 °C, and the coating performance was assessed by electrochemical impedance spectroscopy. The coating morphologies of samples were investigated through field emission scanning electron microscopy and a cell viability/proliferation (MTT) test was performed to evaluate cellular response. A 2.2 μm-thick coating was accomplished, which increased the corrosion resistance to three orders of magnitude higher than that of the bare sample. Hydroxyapatite nanoparticles were added to the silane coating to improve biocompatibility and facilitate bone formation. Changing the concentration of hydroxyapatite nanoparticles not only helped to optimize the barrier properties of the silane coating but also ameliorated MG-63 osteoblastic cell growth. The findings showed great promise to enhance and maintain the corrosion barrier property and induce high osteoblastic differentiation by employing 1000 mg L⁻¹ of hydroxyapatite nanoparticles.

Incorporation of hydroxyapatite nanoparticles in silane coatings improves both corrosion resistance and cell viability on magnesium AZ31 implants.

Determination of Optimum Concentration of Benzimidazole Improving the Cathodic Disbonding Resistance of Epoxy Coating

This study is aimed to evaluate the effect of concentrated benzimidazole (BIM) on the cathodic disbonding (CP) of an epoxy coating applied on steel substrate. For this purpose, the polymeric coatings, formulated with different concentrations of BIM (0 wt.%, 0.5 wt.%, 0.75 wt.%, and 1 wt.%, were subjected to the CP test at the potential of −1.2 V vs. Ag/AgCl during 24 h immersion in 3.5 wt.% NaCl solutions. The optimum formulation was found through taking advantage of the CP test results, FESEM/EDX, and EIS data. Moreover, a pull-off test was used to measure the wet adhesion strength. For insight into the inhibition function of the organic inhibitor, the behavior of steel in the sodium chloride solutions, with and without BIM, was compared using EIS and surface analysis.

Effect of coating composition on the anticorrosion performance of a silane sol–gel layer on mild steel

In this study, the effect of coating composition on the protective performance of an eco-friendly silane sol–gel film applied on a mild steel substrate was investigated using electrochemical impedance spectroscopy and surface analysis methods.