Anticorrosion performance of polyaniline/clay nanocomposites in epoxy coatings

Abstract

Thickness-tunable triple-layer polyaniline (PANI)/clay nanocomposites were synthesized via in situ intercalative polymerization of PANI within the clay layers. The PANI/clay nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. In this study, the thickness of the PANI/clay nanocomposites was easily controlled by adjusting the proportions of PANI and pristine clay. Based on oxygen transmission rate measurements, the oxygen barrier properties of pristine clay can be enhanced by the growth of PANI. Notably, the oxygen barrier property of epoxy loaded PANI/clay nanocomposites was linearly dependent on the PANI growth thickness. After 30 days immersion electrochemical impedance spectroscopy test under saline conditions, the resistance (R c ) of the pure epoxy coating (2.47 Â 10 6 Ω) increased to 5.76 Â 10 10 Ω when 1 wt.% PANI was added to the epoxy coating. However, when 1 wt.% PANI/clay was added into the epoxy coating, the R c of the composite coating increased further to 7.66 Â 10 11 Ω. Notably, the ratio of PANI to PANI/clay was only 36.5 wt.%, indicating synergistic anticorrosion properties can be obtained by the intercalation of PANI/clay additives. Therefore, PANI/clay nanocomposites have a high potential as anticorrosion additives for industrial epoxy resin coatings.

A g‐C3N4/PANI S‐scheme heterojunction with face‐to‐face structure to improve the anticorrosion property on Q235 steel and enhanced mechanism study

“…Besides, the PANI coating layer is the most suitable substrate layer due to the electron conductivity and the density structure; the density structure can suppress the electrons migrated from substrate on surface layers and the electron conductivity can transfer the electron (generated from photocatalytic coating layers) from surface layer to substrate to suppress the corrosion of metals 17–20 . Furthermore, the protonation of PANI electronically conductive is widely employed in the corrosion protection fields and promotes the passivation layer formation on the metal surface, maintaining the redox potential of substrate to further protect the substrate metals 21,22 …”

“…[17][18][19][20] Furthermore, the protonation of PANI electronically conductive is widely employed in the corrosion protection fields and promotes the passivation layer formation on the metal surface, maintaining the redox potential of substrate to further protect the substrate metals. 21,22 Graphitic carbon nitride (g-C 3 N 4 ) has been extensively used in various fields including solar cell, fuel cell, piezoelectricity, photoelectrochemical devices, energy storage and transfer, light-emitting diodes, environmental pollution purification, and anticorrosion coatings because of the low cost, excellent biocompatibility, stable chemical property, corrosion resistance, tunable, and outstanding electronic performances. [23][24][25][26] Different from the traditional photocatalysis, g-C 3 N 4 has suitable redox potential for H 2 evolution and O 2 evolution over water splitting under sunlight irradiation at the same time, that is, g-C 3 N 4 layers has a potential to provide excited electrons migrated on substrate metals through the PANI coating layers and splitting water for charge balance.…”

Ti3C2 MXene/Polyaniline/Montmorillonite Nanostructures toward Solvent-Free Powder Coatings with Enhanced Corrosion Resistance and Mechanical Properties

“…Even though conductive PANI has high anti-corrosion capabilities, its presence weakens the mechanical strengths of organic coatings. It can be practicable to leverage the 2D intrinsic property of Ti 3 C 2 MXene and the reinforcing impact of inorganic clays such as montmorillonite (MMT) to improve the thermal/mechanical properties of organic coatings. , …”