Biobased alkyd/graphene oxide decorated with β–MnO2 nanorods as a robust ternary nanocomposite for surface coating

Abstract

In this paper, a controlled synthesis of graphene oxide nanosheets decorated with β–MnO2 nanorods (β-MnO2 NRs@GO) hybrid was reported via a facile chemical deposition system. For the first time, a biobased ternary nanocomposite series based on linseed oil alkyd filled with β–MnO2 NRs@GO hybrid was developed through a solution casting technique, applied on carbon steel as anticorrosive materials, and dried through an auto-oxidation mechanism. GO nanosheets with thickness <2 nm and β–MnO2 nanorods (NRs) with single-crystallinity, 20−30 nm mean diameter-size, <1 μm length, and exposed with [110] growth orientation of wurtzite structure were synthesized through controlled regimes. The synergetic effects of distributing different β–MnO2 NRs@GO hybrid concentrations in the alkyd matrix were studied to tune the coatings' mechanical and protective properties. The durability and thermal resistivity of the nanocomposite films were investigated. The surface and anticorrosion features of the ternary nanocomposites were studied through water contact angle (WCA), atomic force microscopy, scanning electron microscope, electrochemical analysis, and salt-fog experiment (in 5% NaCl solution). The highest reinforcing improvement with thorn-like protrusions roughness was achieved through a well-distribution of 2.5 wt% β–MnO2 NRs@GO nanofillers in the matrix. The alkyd/β–MnO2 NRs@GO (2.5 wt%) nanocomposite exhibited the highest hydrophobicity (WCA of 141°), root mean square roughness of 15.64 nm, thermal stability, and chemical resistance against 3 N NaOH solution for 24 h. Also, it showed the highest impact resistance (12.74 J), polarization resistance, and stability in a salt-fog environment for 500 h. This fascinating biobased nanocomposite coating provides a promising alternative for replacing petro-based anticorrosive surfaces for the sustainable future environment.