Sol–Gel Coating with 3-Mercaptopropyltrimethoxysilane as Precursor for Corrosion Protection of Aluminium Metal

Sol–gel coatings offer a number of advantages over other methods of protection for metallic materials. In the present work, 3-mercaptopropyltrimethoxysilane (MPTS) was used as the precursor for sol–gel coating on aluminium metal. The gelation of MPTS sol–gel was characterized by Fourier transform infrared spectroscopy (FT-IR) studies. The formed film was found to be stable up to 350 °C as evident from thermogravimetric analysis. X-ray diffraction study and scanning electron microscopy supported the formation of MPTS coating on aluminium surface while the characterization of the coating was done by FT-IR studies. The corrosion inhibition potential of the sol–gel coatings on metal in 3.5% (w/v) of NaCl solution was assessed as a function of different concentrations of MPTS using electrochemical polarization and impedance measurements. The corrosion inhibition efficiency was found to increase with increasing MPTS concentration. The results of the study unravel the use of MPTS as a precursor in the formation of sol–gel coating over aluminium surface so as to protect the metallic surface from corrosion in neutral environment.