Graphene/V2O5@polyaniline ternary composites enable waterborne epoxy coating with robust corrosion resistance

Improvement of the Abrasion and Corrosion Resistance of a Waterborne Epoxy Coating by α-ZrP@PTA-Ce(III) with Dual Corrosion Inhibition Effects

The introduction of poly(tannic acid) (PTA) and cerium ion [Ce(III)] on the surface of α-zirconium phosphate (α-ZrP) endowed the α-ZrP@PTA-Ce(III)/waterborne epoxy composite coating with enhanced corrosion protection and wear resistance performances. The successful preparation of α-ZrP@PTA-Ce(III) was confirmed through X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra. PTA improved the compatibility between α-ZrP@PTA-Ce(III) and the waterborne epoxy resin due to the presence of organic groups from tannic acid. The wear resistance test indicated that the incorporation of α-ZrP@PTA-Ce(III) effectively reduced the coefficient of friction and the wear rate. Electrochemical impedance spectroscopy was used to analyze the corrosion protection performance of unbroken coatings and the self-healing ability of scratched coatings. The incorporation of α-ZrP@PTA-Ce(III) improved the protection performace distinctly. In addition, α-ZrP@PTA-Ce(III) endowed the composite coating with dual corrosion inhibition effects, originating from the PTA film, to prevent the penetration of corrosive media and a dense film that came from the Ce(III) cation. The waterborne epoxy system with enhanced corrosion and wear resistance in this paper broadens the application of α-ZrP.

Improving the Cycling Stability of Aqueous Zinc-Ion Batteries by Preintercalation of Polyaniline in Hydrated Vanadium Oxide

This paper reports the synthesis and characterization of hydrated vanadium oxide (VOH) and chemically preintercalated polyanilines in VOH, labeled as PAVO-H as the cathode material for aqueous zinc-ion batteries. Synthesized PAVO-H has a high surface area and rod-shaped morphology. PAVO-H has an increased interlayer distance of 13.36 Å. PAVO-H offers high specific capacities of 330 and 225 mAh g^-1 at 50 mA g^-1 and 4 A g^-1 of current densities, respectively, with a 92% capacity retention rate of over 3000 cycles. The preintercalation of polyaniline is likely to catalyze the redox reaction and facilitate and simplify transport kinetics. It is also possible that the preintercalation of polyaniline permits the insertion of large hydrated Zn ions and reduces the formation of zinc basic salts.

Improving Corrosion Protection and Friction Resistance of Q235 Steel by Combining Noncovalent Action and Rotating Coating Method

Developing waterborne epoxy (WEP) coatings with excellent corrosion resistance and tribological properties is a key aspect to solve the damage of Q235 steel. In this work, perylene bisimide (PBI) derivatives dispersion graphene (GR) were prepared by a π-π stacking, the highly orientated PBI0.5%/GR0.5%/WEP coating will be prepared by the rotating coating method. Especially, the impedance value reached about 109 Ω·cm2 when the PBI and GR ratio is 1:1. The impedance value of PBI0.5%/GR0.5%/WEP coating increased by 3 orders of magnitude compared with that of pure WEP coating (106 Ω·cm2). Additionally, the coefficient of friction of the coatings was 0.33; compared with that of WEP, the coefficient of friction decreased by 48%, and the wear resistance increased by 87.6%. The results show that the PBI0.5%/GR0.5%/WEP coatings exhibited excellent corrosion resistance and wear resistance properties due to the good dispersion and high orientation of PBI/GR in WEP. It is anticipated that our current work would guide the ongoing efforts to develop a more efficient method to overcome the poor dispersion of GR in waterborne epoxy resin and provide a green coating with excellent corrosion resistance and wear resistance properties.

APTES Modification of Molybdenum Disulfide to Improve the Corrosion Resistance of Waterborne Epoxy Coating

MoS2 has been regarded as a promising addition for the preparation of epoxy-based coatings with high anticorrosion ability. However, its dispersion and compatibility remain significant challenges. In the present work, an organic thin layer was well coated on lamellar molybdenum disulfide (MoS2) via a simple modification of 3-aminopropyltriethoxysilane (APTES). The modification of hydrolyzing APTES on lamellar MoS2 effectively improved the dispersity of MoS2 in water-borne epoxy (WEP) and successfully enhanced the compatibility and crosslinking density of MoS2 with WEP. The influence of introducing MoS2-APTES into WEP coating on anticorrosion property for N80 steel was tested by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and salt spray test. The results exhibited that the |Z|0.01Hz value of MoS2-APTES/WEP still reached 3.647 × 107 Ω·cm2 even after the immersion time of 50 days in 3.5 wt.% NaCl solution, showing an extraordinary performance of corrosion resistance. The enhanced anticorrosion performance of composite coating could be resulted from the apparently increased dispersibility and compatibility of MoS2 in WEP.