Electrodeposition of polyfunctional Ni coatings from deep eutectic solvent based on choline chloride and lactic acid

Abstract

The process of electrodeposition of nickel coatings from electrolytes based on a deep eutectic solvent (DES) mixture of choline chloride and lactic acid with a molar ratio of 1:3 was studied. The physicochemical properties and characteristics of DES, namely, con­ductivity, FT-IR and NMR analysis were determined. FT-IR results confirmed that H-bonds occurring between two components in DES were the main force leading to the eutectic formation. Electrochemical techniques were used to characterize the deposition process and scanning electron microscopy was used to study the deposit morphology. Based on polarization measurements, it has been found that at NiCl2·6H2O content of 1.14 M and a temperature of 75 °C, the limiting current density of nickel electrodeposition was near 2 A dm-2. The polarization of the cathodic nickel deposition varied within -0.63 to 1.1 V at current density of 0.25 A dm-2 It has been shown that an increase of water content in the electrolyte does not significantly affect the current efficiency of the nickel electrodeposition process, which was in a range 85-93 %. However, the increase in water content contributes to the increase of heterogeneity and crystal grains size distribution of galvanic deposits. The established values of the Wagner number indicate the predominance of the primary current density distribution in the process of electrodeposition of nickel coatings. Galvanic coatings possess a highly developed nanostructured surface, exhibit increased capillary properties, and can be used as electrode materials for the process of electrolysis of water.

Corrosion cracking in Mg alloys based bioimplants

“…Various coating methods are employed to protect the surface of different biomedical materials [94][95][96][97]. Spray pyrolisis deposition [98], Electroplating [99], electrodeposition [100], hot dipping [98][99][100][101][102][103][104], physical vapor deposition (PVD) & chemical vapor deposition (CVD) [105][106][107][108][109][110][111][112][113][114][115][116][117], electrochemical vapor deposition (EVD) [118], cold spray [119], thermal spraying [120][121][122][123][124][125], sputtering [126], claddings [64][65][66][67][68][69][70][71][72][73][74]…”

Analyzing the Effect of Extraction Parameters on Phenolic Composition and Selected Compounds in Clove Buds Using Choline Chloride and Lactic Acid as Extraction Agents

“…Various studies have delved into the structural changes, interactions, and hydrogen bonding within systems involving choline chloride and lactic acid [50][51][52][53][54]. Fouriertransform infrared analysis has confirmed hydrogen bond formation within these systems [50,52,53].…”

“…Various studies have delved into the structural changes, interactions, and hydrogen bonding within systems involving choline chloride and lactic acid [50][51][52][53][54]. Fouriertransform infrared analysis has confirmed hydrogen bond formation within these systems [50,52,53]. Research by Alcade et al [51] explored the impact of water on hydrogen bonding and observed minimal disruption within the studied range.…”

“…Research by Alcade et al [51] explored the impact of water on hydrogen bonding and observed minimal disruption within the studied range. 1 H NMR analysis has revealed interactions between the OH groups of lactic acid and choline chloride, leading to chemical shifts and the formation of new signals indicative of intermolecular interactions [52][53][54]. Alcalde et al [51] identified intermolecular interactions facilitated by hydrogen bonding between the chloride ion from choline chloride and lactic acid, with the chloride ion acting as a bridge between choline chloride and multiple lactic acid molecules at a molar ratio greater than 1.…”