Reduced Graphene Oxide Nanoplatelets Functionalized with Nonpolar Aliphatic Groups for High-Performance Coatings against Corrosion

Abstract

A fast and straightforward chemical method to attain reduced graphene oxide (rGO) nanoplatelets that highly functionalized with nonpolar aliphatic groups and their high performance against corrosion is disclosed for the first time. Graphene oxide (GO) was functionalized with trimethoxy(propyl)silane (TMPS) to obtain Propyl-GO through a microwave-assisted method in just 10 min. Scanning electron microscopy–energy-dispersive X-ray revealed a homogeneous distribution of TMPS on the GO surface. Propyl-GO was reduced to obtin highly exfoliated and functionalized nanosheets (Propyl-rGO). Moreover, Propyl-rGO and Propyl-GO were used as additives (0.5 wt %) within an epoxy resin (ER) to obtain ER/Propyl-rGO and ER/Propyl-GO nanocomposite coatings, respectively. ER/Propyl-rGO deposited on A36 structural steel (ER/Propyl-rGO/A36SS) exhibited a hydrophobic behavior, strong adhesion, and significant corrosion protection in a saline medium (1 M NaCl; 58.4 g/L). Interestingly, this functional nanocomposite coating, diminished the corrosion current density by 6 orders of magnitude (i corr = 3.6 × 10–12 A/cm2) compared with A36SS coated with ER (i corr = 1.6 × 10–6 A/cm2). Also, the corrosion potential (E corr) was noticeably decremented from −530 mV (neat ER) to −190 mV (ER/Propyl-rGO). Electrochemical impedance spectroscopy assessments suggested a corrosion mechanism controlled by a charge-transfer adsorption process promoted by basal-plane restructuration from rGO. The strategy proposed herein offers an original pathway to achieve nanocomposites with outstanding hydrophobicity, hardness, adhesion, and exceptional protection against corrosion.

Ag-NP-Decorated Carbon Nanostructures: Synthesis, Characterization, and Antimicrobial Properties

“…The GNPs FTIR spectrum exhibits very weak vibrational bands attributed to the CC bond of the aromatic ring at 1439 and 1565 cm –1 (Figure a) . Similarly, weak signals present at 2164 and 2012 cm –1 are attributed to the symmetrical and asymmetrical C–H bonds at the terminal edges of the GNPs’ carbon lattices. − Moreover, the vibrational band corresponding to the O–H bond of defects within the GNPs’ carbon network is scarcely discernible, making its appearance around 3712 cm –1 . Typically, FTIR signals stemming from graphitic-structured carbon are inherently weak.…”

“… 31 − 33 Moreover, the vibrational band corresponding to the O–H bond of defects within the GNPs’ carbon network is scarcely discernible, making its appearance around 3712 cm –1 . 34 Typically, FTIR signals stemming from graphitic-structured carbon are inherently weak. This phenomenon stems from the crystalline nature of the hexagonal, honeycomb network and the Janus behavior of the 2D carbon structures in predominantly graphitic materials, as reported in prior literature.…”

Flame Retardant and Anticorrosion Behavior of Multifunctional Epoxy Nanocomposite Coatings Containing Graphitic Carbon Nitride/Silanized HfO2 Nanofillers for the Protection of Steel Surface in Automobile Industry

“…The pure epoxy coatings’ low corrosion resistance in a hostile environment is evident by the fact that corrosion products and blisters were noticeably coated around the X-cut after 320 h of immersion (Figure a). On mild steel, the porous and thin epoxy coating layer shows weak force interactions with the metal surface. − On mild steel, it causes the production of pores and microscopic fissures in nonhomogeneous coatings. Because of this, aggressive saltwater species pierce the metal-to-water contact and aid in the breakdown of Fe into Fe 2+ ions.…”

Hydrophobic Polymer/Graphene and Derivatives Based Nanocomposites: A Systematic Rieview

“…AFM analyses revealed a rougher surface for the (GPAH-PEI/GPSS-PAA)60 nanocomposite than for the (PEI/PAA)60 film due to the presence of the nanoparticles, creating a hierarchical structure that increases the surface hydrophobicity. In 2022, Ramirez-Soria and collaborators [14] demonstrated a hydrophilic-hydrophobic transition of epoxy coating by adding only 0.5 wt.% of propyl-functionalized GO or rGO. While the pure epoxy coating presented a hydrophilic WCA of 62°, the epoxy coating loaded with propyl-GO increased the water repellence, exhibiting WCA=94°.…”