Influence of Bath Composition at Acidic pH on Electrodeposition of Nickel-Layered Silicate Nanocomposites for Corrosion Protection

Abstract

Nickel-layered silicates were electrochemically deposited from acidic bath solutions. Citrate was used as a ligand to stabilize nickel (II) ions in the plating solution. The silicate, montmorillonite, was exfoliated by stirring in aqueous solution over 24 hours. The plating solutions were analyzed for zeta-potential, particle size, viscosity, and conductivity to investigate the effects of the composition at various pHs. The solution particles at pH 2.5 (−22.2 mV) and pH 3.0 (−21.9 mV) were more stable than at pH 1.6 (−10.1 mV) as shown by zeta-potential analysis of the nickel-citrate-montmorillonite plating solution.Ecorrfor the films ranged from −0.32 to −0.39 V with varying pH from 1.6 to 3.0. The films were immersed in 3.5% NaCl and the open circuit potential monitored for one month. The coatings deposited at pH 3.0 were stable 13 days longer in the salt solution than the other coatings. X-ray diffraction showed a change in the (111)/(200) ratio for the coatings at the various pHs. The scanning electron microscopy and hardness results also support that the electrodeposition of nickel-montmorillonite at pH 3.0 (234 GPa) had improved hardness and morphology compared to pH 2.5 (174 GPa) and pH 1.6 (147 GPa).

Electrodeposition of Cu-Ni Incorporated with Layered Silicates for Corrosion Protection

“…Polymers (13)(14)(15) and ceramics (16,17) have been integrated with layered silicates to make composites of various properties. With the addition of montmorillonite (MMT) into the pure nickel matrix, shown in our previous work, an increase in strength, hardness, adhesion, and corrosion resistance can be observed (4,18,19).…”

Electrodeposited Zinc-Nickel Nanocomposite Coatings

“…Although several methods are available for the development of nanocomposite coatings, electrodeposition remains a favorable choice due to relative ease of use, low cost, convenience, ability to work at low temperatures and overall control of experimental parameters [39,48,58,65]. A general survey of the literature concerning zinc-nickel nanocomposite coatings found electrochemical deposition to be the main preparation method, so general trends and properties of the coatings formed through electrochemical methods will be the focus of this chapter.…”

“…Exfoliated Mt, which has a plate-like structure, increases the surface area of the material when imbedded in the coating and leads to a more tortuous mean free path of the corrosion cells upon onset [5]. This technique has previously been successful with the incorporation of montmorillonite platelets into pure nickel, nickel-molybdenum and nickel-copper coatings [2,5,8,9,52,58,66]. However, many traditional particles used in composite coatings are spherical in shape.…”

Metal Matrix Composite Coatings of Cupronickel Embedded with Nanoplatelets for Improved Corrosion Resistant Properties

“…Stainless steel (Grade 430) substrates (area of 1.768 cm 2 ) were used as the working electrodes and mechanically polished with different grade emery papers followed by a sequence of cleanings (sonication in ethanol/deionized water) to prepare the substrate surface for electrodeposition. The substrates [46]. After electrodeposition, the composite coating was rinsed with deionized water.…”

“…The slight change in the Cu-Ni ratio of the coatings can be attributed to the embedding of the Mt particles with a greater percentage of Ni over Cu adsorbed onto the surface of the platelets. the metallic matrix is controlled by the parameters of the electrodeposition process including bath concentration of the ions, pH, applied potential, and the current density [46,54]. The amount of the particles embedded into the matrix is in direct relation to the bath concentration, size of particles, solution pH, and type of reinforcement material.…”