CuO-anchored graphene oxide for enhancing mechanical and anticorrosion properties of epoxy coatings in cooling water systems

The surface of the copper (II) oxide (CuO) nanoparticles is modified by 2-amino-5-(4-methoxyphenyl)-1,3,4-thia-diazole (AMPTD) and the resultant AMPTD/CuO particles are anchored on the surface of the graphene oxide (GO) in order to obtain proper dispersion of nanoparticles in the polymer matrix. The XRD and TGA results confirm the grafting of AMPTD utmost on the external hydroxyl groups (OH) present in the CuO nanoparticles and the AMPTD/CuO particles are on the layered structure of GO. The uniform dispersion of CuO nanoparticles after functionalization with AMPTD and GO were proved by TEM and SEM/EDX analysis. The barrier effects of the epoxy-GO/AMPTD-CuO nanocomposites on the mechanical and corrosion protective properties were studied. Corrosion resistance of the brass coated substrates used in the cooling water systems was studied by electro-chemical techniques. Electrochemical studies show an outstanding coating resistance for the epoxy-GO/AMPTD-CuO coated brass (Rcoat: 1.36 x 107 & omega; cm2). Scanning electrochemical microscopy (SECM) results confirm that the copper and zinc dissolution of the epoxy-GO/AMPTD-CuO coated brass substrate are remarkably reduced in comparison with the pure epoxy coated brass even after prolonged exposure to the seawater. In addition, me-chanical properties (hardness, adhesion and tensile strength) were examined for the nanocomposites in marine environment. The enhanced mechanical properties were displayed by the investigated coatings used in cooling water system. The least oxygen and water permeability reported for the epoxy-GO/AMPTD-CuO nanocomposites are due to the uniform coating with insignificant pores. The epoxy-GO/AMPTD-CuO nanocomposites exhibit enhanced mechanical property and outstanding barrier property. Water contact angle measurements for the epoxy-AMPTD/CuO nanocomposites show hydrophobic property (WCA: 157 degrees). Therefore, the epoxy-GO/ AMPTD-CuO can be used as the important protective coating material for brass used in cooling water system.

Automated summary

The surface of CuO nanoparticles was modified with AMPTD and anchored on the surface of GO to achieve proper dispersion in the polymer matrix. TEM and SEM/EDX analysis confirmed the uniform dispersion of AMPTD-functionalized CuO nanoparticles and GO. The epoxy-GO/AMPTD-CuO nanocomposites showed improved mechanical and corrosion protective properties, making them suitable for use in cooling water systems.