Electrophoresis Deposition of Superhydrophobic Silica Nanoparticles Upon Phenol-Furfural Resin for Corrosion Resistant Coating Application

Abstract

Owing to substantial loss and failure of engineering materials due to corrosion of metals, scientists and researchers have extensively worked on corrosion control for a very long time. Corrosion has caused a lot of damage on social and economic levels. In countries like Japan, Germany, and USA, corrosion has cost 1-5% GDP losses. Although corrosion can never be eliminated but efforts could be done to reduce its effect. This research endeavor aims to explore corrosion control of copper and mild steel by developing a superhydrophobic coating. Phenol-Furfural resin (PFR) was synthesized by extracting furfural from non-edible biomass of peanut plant with an extraction efficiency up to 58.3% by acid hydrolysis. Under various conditions and concentrations, furfural was mixed with phenol to produce PFR which was subsequently used as an adhesive in this research. Superhydrophobic silica nanoparticles (SH-Si-NP) have been prepared by the modified Stöber method. These nanoparticles were impregnated into PFR resin and immobilized upon copper and mild steel via electrophoretic deposition (EPD) technique. Different parameters such as distance between electrodes, deposition time, effect of voltage, effect of concentration of PFR and SH-Si-NP have been studied during EPD to optimize the coating conditions. Furfural, PFR, SH-Si-NP and resultant coatings have been characterized by FTIR, UV, TGA, Zetapotential sizer, and water contact angle goniometer. Corrosion-resistant behavior of resultant coatings were studied in 3.5% NaCl aqueous solution via Gamry potentiostat. A superhydrophobic coating deposited on copper substrate in an EPD bath containing 70 g/L PFR and 2.5 g/L SH-Si-NP, for 220 s at 35 V with 2 cm electrodes gap distance, yielded 99 % corrosion control efficiency. On the other hand, for mild steel substrate, an EPD bath containing 30 g/L PFR and 2.5 g/L SH-Si-NP, for 200 s at 45 V with 0.5 cm electrodes gap, yielded 99 % corrosion control efficiency. Results have shown that super hydrophobic silica nanoparticles were successfully incorporated into PFR resin via EPD techniques which served as water barriers and made resultant coatings impermeable thus substantially improved corrosion control efficiency.