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.
