Corrosion performance of epoxy containing Na-MMT/CoFe2O4 nanopowder on 3105 aluminium and the study of molecular dynamics simulation

Organic coatings are used to protect metals from corrosion mainly by two mechanisms: a passive barrier mechanism to protect against exposure to aggressive substances (oxygen, water, salts etc.) or an active protection mechanism by the release of anticorrosive pigments (inhibitors) [1,2]. Na-montmorillonite is one of the most affordable materials that have shown promising results in polymers. In recent years, epoxy/clay nanocomposites have been noticed in coating, aerospace, defense and automobile industriesdue to their excellent properties, such as high-imensional stability, reduced permeability and enhanced mechanical properties [3, 4]. Epoxy nanocomposites matrix, with 1wt% Na-montmorillonite (Na-MMT)/CoFe2O4 nanopowder, havebeen employed as coatings for an AA3105 aluminum specimen. Epoxy-based nanocomposite coating was applied for the first time to the synthesis of a series of Na- MMT/CoFe2O4 nanopowder (below 1wt% nano clay) in a wide range of compositions (from 1 to 5wt% nano clay). CoFe2O4 nanocrystals weresynthesized by a wet chemical coprecipitation approach. The Na-montmorillonite Na-MMT/CoFe2O4nanopowders were prepared by doping method. Composition and structure of nanopowders and nanoparticles were investigated by Fourier transform infrared spectroscopy and X-ray diffraction (XRD)technique and field emission scanning electron microscopy (FE-SEM). The effects of Na-MMT/CoFe2O4nanopowders in the anticorrosion properties of epoxy-coated AA3105 aluminum were studied by meansof electrochemical impedance spectroscopy, potentiodynamic polarization. In this work, molecular dynamics (MD) in the materials studio modeling environment was used to analyze the interface structures,and the interaction energy of the bisphenol-A (DGEBA) molecule anchored on the silicate layer of Na- MMT [5]. As the result, the epoxy nanocomposite with 80wt% Na-MMT and 20wt% CoFe2O4 showed better protection and prolonged lifetime than the other nanocomposites.

Keywords:

Organic Coating , AA 3105 Aluminium , EIS , Polarization , X-Ray Diffraction , Molecular Dynamics Simulation