Novel polyaniline/chitosan/reduced graphene oxide ternary nanocomposites: Feasible reinforcement in epoxy coatings on mild steel for corrosion protection
By Kumar, A. Madhan; Jose, Jobin; Hussein, Mohamed A.
Published in Progress in Organic Coatings
2022
Abstract
Achieving the benefit of synergetic effect using different constituents is an effective approach to design innovative multifunctional composite materials. In this present investigation, a novel anticorrosive epoxy composite coating has been developed based on reduced graphene oxide (rGO) with the polyaniline(PANI)/chitosan(CS) matrix using the in-situ oxidative polymerization. Structure, microstructure, surface characteristics, and the wettability of the developed coatings were analyzed by XRD, FTIR, Raman, XPS, and FE-SEM/EDS techniques. The synthesized ternary PANI/CS/rGO composites exhibited a homogeneous hierarchical morphology with the short rod-like nanostructures, contrary to the morphology of binary PANI/rGO composites. Complete structural analysis results validated the presence of interfacial interaction between the PANI/CS matrix and rGO. Adhesion test results before and after the corrosion confirmed the beneficial role of ternary nanocomposites in improving the adhesion strength between the epoxy and the steel surface. Water contact angle measurement results validated the altered surface hydrophobicity of epoxy coatings upon reinforcing binary and ternary nanocomposite materials. The corrosion test results displayed that the impedance values at the lowest frequency for ternary epoxy composites remain constant at 108 Ω cm2 even after the exposure time of 45 days in NaCl solution, confirming a higher corrosion protective performance on steel substrates. These observed properties suggest that the synthesized ternary composite is a potential candidate for corrosion protection applications.