Why use Ionic Liquids for Electrodeposition?

Abstract

With any great voyage of discovery the explorer should always be asked at the outset "Why are you doing this?" To answer the question "Why use ionic liquids for electrodeposition?" it is first necessary to look at current best practice and find its limitations.It is widely recognised that in 1805 Italian chemist, Luigi Brugnatelli made the first experiments in what we now know as electroplating. Brugnatelli used the newly discovered Voltaic Pile to deposit gold "I have lately gilt in a complete manner two large silver medals, by bringing them into communication by means of a steel wire, with a negative pole of a voltaic pile, and keeping them one after the other immersed in ammoniuret of gold newly made and well saturated" [1]. The process was later improved by John Wright who found that potassium cyanide was a beneficial electrolyte to add for silver and gold plating as it allowed thick adherent deposits to be obtained. Until the middle of the 19th century the production of jewellery and the gilding of decorative items were the main uses of electrodeposition.With an increased understanding of electrochemistry, the practice of metal deposition spread to non-decorative metals such as nickel, brass, tin, and zinc by the 1850s. Even though electroplated goods entered many aspects of manufacturing industry very little changed about the physical processes involved in electrodeposition for about 100 years. It was only with the advent of the electronics industry in the middle of the 20th century that significant changes occurred in the hardware and chemistry of the plating solutions. The post-war period saw an increase in gold plating for electronic components and the use of less hazardous plating solutions. This trend has continued with increased control of hazardous materials to the environment. Improved solution composition and power supply technology has allowed the development of fast and continuous plating of wire, metal strips, semiconductors and complex substrate geometries.Many of the technological developments seen in the electronics industry depend upon sophisticated electroplating including the use of exotic metals and this is one of the drivers for new technology within the electroplating sector. The other Electrodeposition from Ionic Liquids. Edited

Progress in Electrodeposition of Zinc and Zinc Nickel Alloys Using Ionic Liquids

“…There are few reviews that report progress in ILs in the field of electrodeposition of light metals, rare metals, and noble metals [17,18]. Abbott et al [19,20] published a series of articles that discussed the properties of ILs and their possible industrial applications in electroplating, highlighting their significance and that of other applications such as electro-polishing. However, no review focuses exclusively on the Zn and Zn-Ni deposition in ILs and DESs.…”

Electroplating for Decorative Applications: Recent Trends in Research and Development

“…Although both of these techniques are very promising and are strongly pursued in laboratories worldwide, their use on a large scale is still limited. Ionic liquids are mainly used to deposit metals with a Nernst potential below that of water decomposition and, therefore, cannot be electroplated from aqueous baths [37][38][39]. The most common example is the electrodeposition of aluminum.…”

Electropolishing of Re-melted SLM Stainless Steel 316L Parts Using Deep Eutectic Solvents: 3 × 3 Full Factorial Design

“…In these cases, the amount of the primary current distribution has a significant effect on the material dissolution (mass transfer), which leads to a reduction in the surface roughness by several microns [2] [3]. Anodic brightening improves the surface roughness due to control of the dissolution rate for the metal microstructure [4][5][6][7][8][9][10].…”

“…Abbott and colleagues introduced a new alternative for electropolishing based on a mixture of choline chloride and ethylene glycol, a type III deep eutectic solvent called Ethaline 200 [6]. This approach gave considerable benefits, including high current efficiency, negligible gas evolution at the anode/solution interface and the use of a relatively benign liquid compared to the acid mixture solution normally used [14].…”

“…Recently, Abbott and colleagues have introduced the concept of Deep Eutectic Solvents (DES) as a sub-category of ionic liquids [6,13,14,[17][18][19]. The DES is a fluid resulting from the mixing of two or three components which are capable of combining each other, frequently through hydrogen bond interactions.…”