Andrew P. Abbott

Novel solvent properties of choline chloride/urea mixturesElectronic supplementary information (ESI) available: spectroscopic data. See http://www.rsc.org/suppdata/cc/b2/b210714g/

Eutectic mixtures of urea and a range of quaternary ammonium salts are liquid at ambient temperatures and have interesting solvent properties.

Electrodeposition from Ionic Liquids

PREFACE BASIC CONSIDERATIONS OF DEPOSITION IN IONIC LIQUIDS SYNTHESIS OF IONIC LIQUIDS AlCl3 Based First Generation Ionic Liquids Air and Water Stable Ionic Liquids Deep Eutectic Solvents PHYSICOCHEMICAL PROPERTIES OF IONIC LIQUIDS ELECTRODEPOSITION OF METALS Metal Deposition in AlCl3 Based Ionic Liquids Metal Deposition in Air and Water Stable Ionic Liquids Metal Deposition in Deep Eutectic Solvents Troublesome Aspects ELECTRODEPOSITION OF ALLOYS ELECTRODEPOSITION OF SEMICONDUCTORS ELECTRODEPOSITION OF CONDUCTING POLYMERS ELECTRODEPOSITION OF NANOCRYSTALLINE METALS AND ALLOYS ELECTRODEPOSITION ON THE NANOSCALE PLASMA ELECTROCHEMISTRY TECHNICAL ASPECTS Counter Electrode Reactions / Metal Dissolution Reference Electrodes Upscaling Recycling Impurities SURFACE PRETREATMENT / ELECTROPOLISHING PLATING PROTOCOLS FUTURE DIRECTIONS

Electrodeposition of copper composites from deep eutectic solvents based on choline chloride

Here we describe for the first time the electrolytic deposition of copper and copper composites from a solution of the metal chloride salt in either urea-choline chloride, or ethylene glycol-choline chloride based eutectics. We show that the deposition kinetics and thermodynamics are quite unlike those in aqueous solution under comparable conditions and that the copper ion complexation is also different. The mechanism of copper nucleation is studied using chronoamperometry and it is shown that progressive nucleation leads to a bright nano-structured deposit. In contrast, instantaneous nucleation, at lower concentrations of copper ions, leads to a dull deposit. This work also pioneers the use of the electrochemical quartz crystal microbalance (EQCM) to monitor both current efficiency and the inclusion of inert particulates into the copper coatings. This technique allows the first in situ quantification or particulate inclusion. It was found that the composition of composite material was strongly dependent on the amount of species suspended in solution. It was also shown that the majority of material was dragged onto the surface rather than settling on to it. The distribution of the composite material was found to be even throughout the coating. This technology is important because it facilitates deposition of bright copper coatings without co-ligands such as cyanide. The incorporation of micron-sized particulates into ionic liquids has resulted, in one case, in a decrease in viscosity. This observation is both unusual and surprising; we explain this here in terms of an increase in the free volume of the liquid and local solvent perturbation.

Processing of metals and metal oxides using ionic liquids

Hydrometallurgy lies at the heart of many industrial processes and is the source of a large volume of aqueous waste. Treating dilute streams of acidic and basic by-products is both energy and chemical intensive, and is one of the largest sources of metal-based emissions into the environment. Over the past decade, numerous studies have been made into the use of ionic liquids for metal dissolution, extraction and recovery. This article critically reviews the potential efficacy of these methods and signposts the areas where further research is needed.

O-Acetylation of cellulose and monosaccharides using a zinc based ionic liquid

The efficient O-acetylation of monosaccharides and cellulose is demonstrated using a Lewis acidic ionic liquid based on choline chloride and zinc chloride.

Preparation of novel, moisture-stable, Lewis-acidic ionic liquids containing quaternary ammonium salts with functional side chains

A range of novel, moisture-stable, Lewis-acidic ionic liquids has been prepared by mixing appropriate molar ratios of MCl2 (M = Zn and/or Sn) and quaternary ammonium salts of formula [Me3NC2H4Y]Cl (Y = OH, Cl, OC(O)Me, OC(O)Ph); the influence of substituent Y and metal M on the physical properties of the melts has been investigated.

Molecular motion and ion diffusion in choline chloride based deep eutectic solvents studied by 1H pulsed field gradient NMR spectroscopy.

Deep Eutectic Solvents (DESs) are a novel class of solvents with potential industrial applications in separation processes, chemical reactions, metal recovery and metal finishing processes such as electrodeposition and electropolishing. Macroscopic physical properties such as viscosity, conductivity, eutectic composition and surface tension are already available for several DESs, but the microscopic transport properties for this class of compounds are not well understood and the literature lacks experimental data that could give a better insight into the understanding of such properties. This paper presents the first pulsed field gradient nuclear magnetic resonance (PFG-NMR) study of DESs. Several choline chloride based DESs were chosen as experimental samples, each of them with a different associated hydrogen bond donor. The molecular equilibrium self-diffusion coefficient of both the choline cation and hydrogen bond donor was probed using a standard stimulated echo PFG-NMR pulse sequence. It is shown that the increasing temperature leads to a weaker interaction between the choline cation and the correspondent hydrogen bond donor. The self-diffusion coefficients of the samples obey an Arrhenius law temperature-dependence, with values of self-diffusivity in the range of [10(-10)-10(-13) m(2) s(-1)]. In addition, the results also highlight that the molecular structure of the hydrogen bond donor can greatly affect the mobility of the whole system. While for ethaline, glyceline and reline the choline cation diffuses slower than the associated hydrogen bond donor, reflecting the trend of molecular size and molecular weight, the opposite behaviour is observed for maline, in which the hydrogen bond donor, i.e. malonic acid, diffuses slower than the choline cation, with self-diffusion coefficients values of the order of 10(-13) m(2) s(-1) at room temperature, which are remarkably low values for a liquid. This is believed to be due to the formation of extensive dimer chains between malonic acid molecules, which restricts the mobility of the whole system at low temperature (<30 °C), with malonic acid and choline chloride having almost identical diffusivity values. Diffusion and viscosity data were combined together to gain insights into the diffusion mechanism, which was found to be the same as for ionic liquids with discrete anions.

Electrodeposition of nickel using eutectic based ionic liquids.

Abstract The electrolytic deposition of nickel is demonstrated using a solution of the metal chloride salt separately in either a urea or ethylene glycol/choline chloride based ionic liquid. It is shown that the deposition kinetics and thermodynamics differ from the aqueous processes and these result in different deposit morphologies. It is also shown for the first time that bright metal coatings can be obtained from these liquid systems by adding various brightening agents and deposits can be put directly onto substrates such as aluminium without prior treatment. The general mechanism by which brighteners function in ionic liquids is also discussed.

The electrodeposition of silver composites using deep eutectic solvents.

Silver is an important metal for electronic connectors, however, it is extremely soft and wear can be a significant issue. This paper describes how improved wear resistant silver coatings can be obtained from the electrolytic deposition of silver from a solution of AgCl in an ethylene glycol/choline chloride based Deep Eutectic Solvent. An up to 10-fold decrease in the wear volume is observed by the incorporation of SiC or Al(2)O(3) particles. The work also addresses the fundamental aspect of speciation of silver chloride in solution using EXAFS to probe solution structure. The size but not the nature of the composite particles is seen to change the morphology and grain size of the silver deposit. Grain sizes are shown to be consistent with previous nucleation studies. The addition of LiF is found to significantly affect the deposit morphology and improve wear resistance.

The regiospecific Fischer indole reaction in choline chloride·2ZnCl2 with product isolation by direct sublimation from the ionic liquid

The Fischer indole synthesis occurs in high yield with one equivalent of the ionic liquid choline chloride[middle dot]2ZnCl(2); exclusive formation of 2,3-disubstituted indoles is observed in the reaction of alkyl methyl ketones, and the products readily sublime directly from the ionic liquid.