Table of Contents

Cover

Title Page

List of Contributors

Abbreviations

Chapter 1: Why Use Ionic Liquids for Electrodeposition?

1.1 Nonaqueous Solutions
1.2 Ionic Fluids
1.3 What Is an Ionic Liquid?
1.4 Technological Potential of Ionic Liquids
1.5 Conclusions
References

Chapter 2: Synthesis of Ionic Liquids

2.1 Nanostructured Metals and Alloys Deposited from Ionic Liquids
References
2.2 Air- and Water-Stable Ionic Liquids
References
2.3 Eutectic-Based Ionic Liquids
References

Chapter 3: Physical Properties of Ionic Liquids for Electrochemical Applications

3.1 Introduction
3.2 Thermal Properties
3.3 Viscosity
3.4 Density
3.5 Refractive Index
3.6 Polarity
3.7 Solubility of Metal Salts
3.8 Electrochemical Properties
3.9 Conclusion and Future Prospects
Acknowledgments
References

Chapter 4: Electrodeposition of Metals

4.1 Electrodeposition in AlCl₃-Based Ionic Liquids
References
4.2 Electrodeposition of Refractory Metals from Ionic Liquids
References
4.3 Deposition of Metals from Nonchloroaluminate Eutectic Mixtures
References
4.4 Troublesome Aspects
References
4.5 Complexation and Redox Behavior of Metal Ions in Ionic Liquids
References

Chapter 5: Electrodeposition of Alloys

5.1 Introduction
5.2 Electrodeposition of Al-Containing Alloys from Chloroaluminate Ionic Liquids
5.3 Electrodeposition of Zn-Containing Alloys from Chlorozincate Ionic Liquids
5.4 Fabrication of a Porous Metal Surface by Electrochemical Alloying and Dealloying
5.5 Nb–Sn
5.6 Air- and Water-Stable Ionic Liquids
5.7 Deep Eutectic Solvents
5.8 Summary
References

Chapter 6: Electrodeposition of Semiconductors from Ionic Liquids

6.1 Introduction
6.2 Group IV Semiconductors
6.3 II–VI Compound Semiconductors
6.4 III–V Compound Semiconductors
6.5 Other Compound Semiconductors
6.6 Conclusions
References

Chapter 7: Conducting Polymers

7.1 Introduction
7.2 Electropolymerization – General Experimental Procedures
7.3 Synthesis of Conducting Polymers in Chloroaluminate ILs
7.4 Synthesis of Conducting Polymers in Air- and Water-Stable ILs
7.5 Characterization
7.6 Conclusions and Outlook
References

Chapter 8: Nanostructured Materials

8.1 Nanostructured Metals and Alloys Deposited from Ionic Liquids
References
8.2 Electrodeposition of Ordered Macroporous Materials from Ionic Liquids
References
8.3 Electrodeposition of Nanowires from Ionic Liquids
References
8.4 Electrochemical Synthesis of Nanowire Electrodes for Lithium Batteries
References

Chapter 9: Ionic Liquid–Solid Interfaces

9.1 Introduction
9.2 IL–Au(1 1 1) Interface
9.3 IL–HOPG Interface
9.4 Influence of Solutes on the IL–Electrode Interfacial Structure
9.5 Thin Films of Ionic Liquids in Ultrahigh Vacuum (UHV)
9.6 Outlook
References

Chapter 10: Plasma Electrochemistry with Ionic Liquids

10.1 Introduction
10.2 Concepts and Principles
10.3 Early Studies
10.4 The Stability of Ionic Liquids in Plasma Experiments
10.5 Plasma Electrochemical Metal Deposition in Ionic Liquids
10.6 Conclusions and Outlook
Acknowledgments
References

Chapter 11: Impedance Spectroscopy

11.1 Introduction
11.2 Measurement: Basics and Pitfalls
11.3 Analysis of Experimental Data
11.4 Application: IL Interfaces at Metal Electrodes
References

Chapter 12: Technical Aspects

12.1 Metal Dissolution Processes
References
12.2 Reference Electrodes for Use in Room-Temperature Ionic Liquids
References
12.3 Process Scale-Up
References
12.4 Toward Regeneration and Reuse of Ionic Liquids in Electroplating
References
12.5 Impurities
A.1 Protocol for the Deposition of Zinc from a Type III Ionic Liquid
A.2 Electroplating Experiment
References

Chapter 13: Plating Protocols

13.1 Electrodeposition of Al from [C₂mim]Cl/AlCl₃
13.2 Electrodeposition of Al from 1-Butyl-3-methylimidazoliumchloride–AlCl₃–Toluene
13.3 Electrodeposition of Al from [C₂mim] NTf₂/AlCl₃
13.4 Electrodeposition of Al from [C₄ mpyr]NTf₂/AlCl₃
13.5 Electrodeposition of Li from [C₄ mpyr]NTf₂/LiNTf₂
13.6 Electrodeposition of Ta from [C₄ mpyr]NTf₂
13.7 Electrodeposition of Zinc Coatings from a Choline Chloride: Ethylene-Glycol-Based Deep Eutectic Solvent
13.8 Electrodeposition of Nickel Coatings from a Choline Chloride: Ethylene-Glycol-Based Deep Eutectic Solvent
References

Chapter 14: Future Directions and Challenges

14.1 Impurities
14.2 Counter Electrodes/Compartments
14.3 Ionic Liquids for Reactive (Nano)materials
14.4 Nanomaterials/Nanoparticles
14.5 Cation/Anion Effects
14.6 Polymers for Batteries and Solar Cells
14.7 Variable-Temperature Studies
14.8 Intrinsic Process Safety
14.9 Economics (Price, Recycling)
14.10 Fundamental Knowledge Gaps

Index

End User License Agreement

List of Illustrations

Chapter 1: Why Use Ionic Liquids for Electrodeposition?

Figure 1.1 Publications on the topic of electrodeposition using ionic liquids, 1991 to mid-2015 (Web of Science).
Figure 1.2 Summary of the elements deposited as single metals or alloys.

Chapter 2: Synthesis of Ionic Liquids

Scheme 2.1.1 General synthesis route to haloaluminate-based ionic liquids.
Figure 2.1.1 Examples of cations commonly used for the synthesis of ionic liquids.
Scheme 2.1.2 Quaternization reaction of 1-alkylimidazoles.
Scheme 2.1.3 Reaction between [EMIM]Cl and AlCl₃.
Scheme 2.1.4 Autosolvolysis of AlCl₄ melts.
Scheme 2.2.1 General synthetic route to producing air- and moisture-stable ionic liquids.
Figure 2.2.1 Structure, full name, and abbreviations for the anions discussed in this section.
Figure 2.2.2 A comparison of the hydrolytic stability of four 1-hexyl-3-methylimidazolium ionic liquids [HMIM]X ionic liquids. To 25 g of each ionic liquid, 7.1 mol% water was added. These solutions were heated to 60 °C and the fluoride content measured once an hour for 8 hours. All measurements were performed at Merck KGaA, Darmstadt, Germany.
Figure 2.3.1 Schematic representation of a eutectic point on a two-component phase diagram.
Figure 2.3.2 Schematic representation of the complexation occurring when a Lewis acid or a Brønsted acid interacts with a quaternary ammonium salt.
Scheme 2.3.1 Example syntheses of metal oxide-based ionic liquids.

Chapter 3: Physical Properties of Ionic Liquids for Electrochemical Applications

Figure 3.1 Phase diagram for [C_nmim]BF₄ showing the melting (), glass (), and clearing () transitions measured by differential scanning calorimetry.
Figure 3.2 Relation between thermal decomposition temperatures (T_d) of [C_nmim]-type ILs and alkyl chain length (n). Anion species are Cl⁻: (), I⁻: (), $c03-math-019$ : (), $c03-math-020$ : () and [Tf₂N]⁻: ().
Scheme 3.1 Pyrolysis mechanism of ILs containing halide anions.
Figure 3.3 Plot of refractive indices (n) versus density (ρ) for a series of ILs.
Figure 3.4 Solvatochromic probe molecules.
Figure 3.5 ILs containing multivalent anion.
Figure 3.6 Structure of zwitterionic salt for selective ion-conductive materials.

Chapter 4: Electrodeposition of Metals

Figure 4.1.1 Simplified electrochemical windows of 1-butyl-pyridinium chloride and 1-ethyl-3-methyl-imidazolium chloride.
Figure 4.1.2 Cathodic scan cyclic voltammograms of near-Lewis-neutral and LiCl-buffered [EMIM]Cl/AlCl₃ ionic liquids at a W working electrode. Scan rate: 100 mV s⁻¹. (a) Negative scan limit: −2.2 V; (b) negative scan limit: −2.7 V.
Figure 4.1.3 Cyclic voltammogram of neutral buffered, unprotonated melt at tungsten (a) and 303 stainless steel (b).
Figure 4.1.4 Cyclic voltammogram at tungsten of a neutral buffered, ionic liquid protonated to a partial pressure of 6.1 Torr HCl.
Figure 4.1.5 XRD pattern of nanocrystalline Al with a grain size of 12 ± 1nm.
Figure 4.1.6 Size distribution of nanocrystalline Al TEM image.

Chapter 5: Electrodeposition of Alloys

Figure 5.1 Plan-view SEM images of silver wire samples that have been electrodeposited with 12.73 C cm⁻² of zinc followed by dealloying at 0.6 V. The amounts (in C cm⁻²) of the zinc that were dealloyed are as follows: (a) 1.59, (b) 4.77, (c) 9.55, and (d) 12.73 C cm⁻². The temperature was 150 °C [43] and the scale bar in the SEM images is 2 μm. (Yeh (2006) [43]. Reproduced with permission of American Chemical Society.)
Figure 5.2 Staircase cyclic voltammograms of (......) 0.3 M Zn(II), (----) 0.2 M Mn(II), and (——) the mixture of 0.16 M Zn(II) + 0.1 M Mn(II) recorded at W electrode in [TBMA]Tf₂N ionic liquid. Temperature, 80 °C. Scan rate, 50 mV s⁻¹ [53]. (Chen (2007) [53]. Reproduced with permission of Elsevier.)
Figure 5.3 A comparison of two cyclic voltammograms of 0.1 M FeCl₂/[Py_1,4]TfO and (0.1 M FeCl₂ + 2.75 M AlCl₃)/[Py_1,4]TfO at 100 °C on copper at two different switching potentials. Scan rate, 10 mV s⁻¹. The CV of neat [Py_1,4]TfO on copper at 100 °C is shown in the inset [58]. (Giridhar (2014) [58] http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp00613e#!divAbstract. Used under CC-BY-3.0 https://creativecommons.org/licenses/by/3.0/.)
Figure 5.4 Voltammograms (scan rate, 20 mV s⁻¹) for a Pt microelectrode (0.5 mm diameter) immersed in (a) 1 : 2 ChCl:EG, and (b) 1 : 2 ChCl:U DES containing 0.05 M SnCl₂ and 0.5 M ZnCl₂ [67]. (Abbott (2007) [67]. Reproduced with permission of Elsevier.)

Chapter 6: Electrodeposition of Semiconductors from Ionic Liquids

Figure 6.1 In situ STM images of Au(111) in (a) 0.1 M SiCl₄/[C₄mPyr][N(Tf)₂] at –1.6 V and (b) 0.1 M SiCl₄/[C₄mPyr][FAP] at –0.6 V. In situ I/U tunneling spectroscopy reveals a band gap of 1.1 eV (insets) indicating that semiconducting Si has been deposited in both solutions.
Figure 6.2 XRD pattern of crystalline Ga-doped Ge deposited electrochemically on Cu from [C₂mim][N(Tf)₂] at room temperature.
Figure 6.3 SEM images of free-standing Ge nanowires (a), nanotubes with 220 nm in diameter (b), and nanotubes with 400 nm in diameter (c) electrodeposited from 0.1 M GeCl₄/[C₂mim][N(Tf)₂].
Figure 6.4 In situ AFM images of electroless deposition of Sb on Ga from 0.25 M SbCl₃/[C₄mPyr][N(Tf)₂].

Chapter 7: Conducting Polymers

Figure 7.1 The chemical structure of common conducting polymers, in their undoped, neutral form.
Figure 7.2 The redox cycling of poly(pyrrole) involving intercalation and expulsion of (a) the anion, or (b) the cation, from the electrolyte to effect charge balance.
Figure 7.3 The polymerization mechanism for heterocyclic polymers.
Figure 7.4 The cations and anions utilized for the electrochemical synthesis of conducting polymers in ILs, and the abbreviations used herein.
Figure 7.5 Poly(pyrrole) films grown in [C₄mpyr][NTf₂] (a), [C₂mim][NTf₂] (b), and PC/Bu₄N PF₆ (c), by constant potential onto Pt.
Figure 7.6 Growth of poly(pyrrole) in (a) air-equilibrated [C₄mim][PF₆], (b) [C₄mim][PF₆] after N_2(g) purging, and (c) deoxygenated 0.25 M Bu₄N PF₆ in PC, 100 mV s⁻¹, 30 cycles.
Figure 7.7 Poly(pyrrole) grown along the surface of [C₂mim][NTf₂] at (a) constant potential, (b) with a circular auxiliary electrode, (c) using voltage pulses.
Figure 7.8 Cyclic voltammograms of thiophene polymerization (0.2 M, 50 mV s⁻¹) onto a Pt working electrode; (a) growth and (b) postgrowth in [C₂mim][NTf₂], (c) growth and (d) postgrowth in [C₄mpyr][NTf₂], versus a Ag pseudo reference electrode. Arrows indicate the peak development with successive scans.
Figure 7.9 Cyclic voltammograms of bithiophene polymerization (0.1 M, 50 mV s⁻¹) (a) growth and (b) postgrowth in [C₂mim][NTf₂], (c) growth and (d) postgrowth in [C₄mpyr][NTf₂], versus a Ag pseudo reference electrode. Arrows indicate the peak development with successive scans.
Figure 7.10 Cyclic voltammograms of terthiophene polymerization (0.01 M, 50 mV s⁻¹) (a) growth and (b) postgrowth in [C₂mim][NTf₂], (c) growth and (d) postgrowth in [C₄mpyr][NTf₂], versus a Ag pseudo reference electrode.
Figure 7.11 Cyclic voltammograms of PEDOT (0.1 M, 20 cycles, every third shown, 100 mV s⁻¹). (a) Film I growth in acetonitrile/Bu₄N ClO₄. (b) Postgrowth of films I and II in acetonitrile/Bu₄N ClO₄. (c) Film II – growth in [C₂mim][NTf₂] and (d) postgrowth of films I and II in [C₂mim][NTf₂], versus an Ag pseudo reference electrode.
Figure 7.12 Current–time responses to potential step from 0 to 1.4 V for the electropolymerization of 0.1 M EDOT onto ITO electrodes in different media: (a) 0.1 M Bu₄N ClO₄ in acetonitrile, (b) [C₄mpyr][NTf₂], (c) 0.1 M LiNTf₂ in acetonitrile, and (d) [C₂mim][NTf₂].
Figure 7.13 High resolution SEM images of TiO₂-containing PPP nanowires after dissolution of the polycarbonate membrane.
Figure 7.14 SEMs of poly(thiophene) films grown from [C₂mim][NTf₂] (a–c) and [C₄mpyr][NTf₂] (d–f), viewed from above (a, d and b, e) and edge view (c, f).
Figure 7.15 SEM images of reduced PEDOT films on ITO, prepared by cyclic voltammetry (20 cycles, 100 mV s⁻¹) from (a) 0.1 M LiNTf₂ in acetonitrile, (b) [C₄mpyr][NTf₂], (c) [C₂mim][NTf₂], and (d) 0.1 M Bu₄N ClO₄ in acetonitrile.
Figure 7.16 Examples of Raman spectra of (a) poly(pyrrole) and (b) poly(terthiophene), from [C₂mim][NTf₂].
Figure 7.17 Example of the deconvolution of XPS spectra for poly(pyrrole) containing [NTf₂] anions and [C₂mim] cations.
Figure 7.18 UV-vis spectra of PEDOT films (a) deposited in [C₂mim][NTf₂], oxidized 20 min at 0.8 V, and reduced 20 min at −1 V in the IL, (b) grown in [C₂mim][NTf₂], oxidized 20 min at 0.8 V, and reduced 20 min at −1 V in acetonitrile/0.1 M Bu₄N ClO₄ solution (c) spectroelectrochemistry of PEDOT in 0.1 M LiNTf₂ in acetonitrile after deposition from [C₄mpyr][NTf₂] from −1 to 0.9 V.
Figure 7.19 (a) ³¹P, (b) ¹⁹F, and (c) ¹³C NMR spectra of polypyrrole grown at constant potential in [P_6,6,6,14][NTf₂].

Chapter 8: Nanostructured Materials

Figure 8.1.1 The crystallite size dependence of the pulsed current density for gold deposits deposited from a commercial sulfite bath without any additives [29].
Figure 8.1.2 The effect of the $c08-math-022$ time on the nanostructure of gold deposits. An average current density of $c08-math-023$ was used for all experiments [29].
Figure 8.1.3 The activity of different grain refiners (butanediamine, ammonium ethylenediamine tetraacetic acid, benzosulfimide) on the nanostructure of gold deposits [29].
Figure 8.1.4 The influence of the $c08-math-028$ concentration of the electrolyte on the alloy composition [29].
Figure 8.1.5 The influence of the temperature (left axis) and the pulse current density (right axis) on the alloy composition of FeNi alloys [29].
Figure 8.1.6 The influence of the benzoic acid concentration on the crystallite size of aluminum deposits [74].
Figure 8.1.7 Cyclic voltammograms for aluminum deposition with increasing amounts of additive (benzoic acid) [74].
Figure 8.1.8 Temperature dependence of the crystallite size for Al samples prepared from additive-containing electrolyte [74].
Figure 8.1.9 X-ray diffraction pattern of an AlMn alloy prepared from a Lewis acid $c08-math-087$ electrolyte [74].
Figure 8.1.10 (a) A biphasic mixture of the ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide containing $c08-math-098$ at room temperature. (b) The biphasic mixture becomes monophasic at 80 °C [89].
Figure 8.1.11 Cyclic voltammogram recorded at the Au(111) substrate in the ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide containing $c08-math-100$ (from the upper phase of the mixture) at room temperature. The scan rate was $c08-math-101$ [89].
Figure 8.1.12 SEM micrographs of electrodeposited Al on gold formed after potentiostatic polarization for 2 h in the upper phase of the mixture $c08-math-102$ : (a) at room temperature, $c08-math-103$ ; (b) at 100 °C, $c08-math-104$ . (c) EDAX profile for the area shown in the SEM micrograph (a) [89].
Figure 8.1.13 XRD patterns of an electrodeposited Al layer obtained potentiostatically at $c08-math-107$ for 2 h in the upper phase of the mixture $c08-math-108$ at 100 °C on a glassy carbon substrate. Inset: FWHM of Al(111) peak of XRD patterns [89].
Figure 8.1.14 SEM micrographs of electrodeposited Al films on gold formed in the upper phase of the mixture $c08-math-111$ after potentiostatic polarization for 2 h at (a) room temperature ( $c08-math-112$ , corresponding $c08-math-113$ ); (b) 50 °C ( $c08-math-114$ , corresponding $c08-math-115$ ); (c) 75 °C ( $c08-math-116$ , corresponding $c08-math-117$ ); and (d) 100 °C ( $c08-math-118$ , corresponding $c08-math-119$ ) [91].
Figure 8.1.15 SEM micrographs of electrodeposited Al films on gold formed after potentiostatic polarization for 1 h in the upper phase of the mixture $c08-math-120$ at (a) 25 °C ( $c08-math-121$ , corresponding $c08-math-122$ ); (b) 50 °C ( $c08-math-123$ , corresponding $c08-math-124$ ); (c) 75 °C ( $c08-math-125$ , corresponding $c08-math-126$ ); and (d) 100 °C ( $c08-math-127$ , corresponding $c08-math-128$ ) [91].
Figure 8.1.16 Cyclic voltammogram of the ionic liquid $c08-math-136$ saturated with $c08-math-137$ on gold at room temperature. Scan rate $c08-math-138$ [93].
Figure 8.1.17 (a) SEM micrograph of nanocrystalline copper obtained potentiostatically on Au in the ionic liquid $c08-math-139$ saturated with $c08-math-140$ at a constant potential for 2 h at room temperature. (b) EDX profile of the area shown in the SEM micrograph [93].
Figure 8.2.1 (a) SEM image of a PS colloidal crystal. (b) SEM image of a 3DOM structure of nickel by electrodeposition.
Figure 8.2.2 High-resolution SEM images of 3DOM Ge obtained after applying a constant potential of −1.9 V (vs Ag quasi-reference electrode) for 3 h at room temperature. Scale bars: (a) 500 nm, (b) 2 µm.
Figure 8.2.3 Optical photographs of the deposited Ge photonic crystal (pore size about 370 nm) on the ITO glass substrate showing a color change when the angle of incident white light is changed. The deposit was obtained after potentiostatic polarization at −2 V (vs Ag quasi-reference electrode) for 30 min in [C₂mim][NTf₂].
Figure 8.2.4 Anode performance in half-cells: (a) discharge–charge curves of 3DOM Ge between 0 and 2 V at 0.2C; (b) cycling behaviors of the 3DOM Ge and dense Ge electrodes; (c) cycling performances of the 3DOM Ge and dense Ge electrodes under different rates; (d) capacity vs. cycle number and discharge/charge rate.
Figure 8.2.5 SEM images of 3DOM silicon from PS templates with different diameters: (a) with 235 nm particles, (b) with 455 nm particles, and (c) with 515 nm particles. The insets show the 2D fast Fourier transform (FFT) analysis of the samples.
Figure 8.2.6 SEM image of PS template assembled from 500-nm-diameter PS spheres on ITO substrate (a). SEM images of 2D macroporous thin film electrodeposited (b) at room temperature and (c) at 90 °C.
Figure 8.2.7 Illustration of the formation of the two kinds of 2D architectures. (a) PS template obtained by self-assembly; (b) PS template obtained after annealing at elevated temperature; (c, d) infiltration of the template by electrodeposition for 15 min; (e, f) removal of the PS spheres by DMF to obtain a 2D film.
Figure 8.2.8 Optical photographs of deposited 2D ordered structure (PS sphere size 500 nm, SiCl₄:GeCl₄ = 1 : 1) on ITO substrate showing a color variation with changing the angle of incident white light.
Figure 8.2.9 SEM image of Ga macroporous structure obtained after the dissolution of the PS template. Deposition potential: −1.4 V, deposition time: 1 h.
Figure 8.2.10 Cyclic voltammogram for the Cu/polystyrene template electrode in [C₂mim]Cl/AlCl₃ at a scan rate of 10 mV s⁻¹.
Figure 8.2.11 (a, b) SEM image of macroporous PEDOT on gold after removal of the PS template.
Figure 8.2.12 Photographs of the macroporous PEDOT film deposited on gold. The PEDOT film turns green, red, blue, and orange with slight change of the angle of the incident visible light.
Figure 8.2.13 Schematic illustration of 3DOM bilayer films electrodeposited from ionic liquids.

Chapter 9: Ionic Liquid–Solid Interfaces

Figure 9.1 Typical normal forces versus apparent separation data for [EMIm] FAP (a–c), [BMIm] FAP (d–f), [HMIm] FAP (g–i), and [BMIm] I (j–l) at Au(1 1 1) as a function of potential. For the chemical structures of the ILs: carbon atoms are shaded gray, nitrogen are blue, hydrogen are white, fluorine are yellow, phosphorous are pink, and iodide are red.
Figure 9.2 In situ STM images of the Au(1 1 1) surface at the OCP and at –1.0 V in [Py_1,4] FAP (a, d), [EMIm] FAP (b, e), and [HMIm] FAP (c, f).
Figure 9.3 In situ STM images of the Au(1 1 1) surface at the OCP and at –1.0 V in [Py_1,4] Tf₂N (a, d), [EMIm] Tf₂N (b, e), and [OMIm] Tf₂N (c, f).
Figure 9.4 Typical normal forces versus apparent separation data for [HMIm] FAP (a–c), [EMIm] FAP (d–f), [EMIm] Tf₂N (g–i), and [OMIm] Tf₂N (j–l) at HOPG as a function of potential. For the chemical structures, carbon atoms are shaded gray; nitrogen are blue, hydrogen are white, fluorine are yellow, phosphorous are pink, sulfur are brown, and oxygen are red.
Figure 9.5 Normal force versus apparent separation (a–c) for [OMIm] Tf₂N at –2.0 V as a function of time.
Figure 9.6 In situ STM images of the Au(1 1 1) surface in [OMIm] Tf₂N at different electrode potentials.
Figure 9.7 AM-AFM phase images of the pure [EMIm] TF₂N Stern layer adsorbed to a graphite (HOPG) substrate. The slow scan direction of all images is down the images. Image sizes are all 15 nm × 15 nm. The interfacial data were collected at differing applied potentials and OCP (indicated in the figure). The OCP for the pure [EMIm] Tf₂N system was 0.26 V versus Pt.
Figure 9.8 AM-AFM phase images of [EMIm] TF₂N + 0.1 wt% Li Tf₂N and [EMIm] Tf₂N + 0.1 wt% [EMIm] Cl Stern layer adsorbed to a graphite (HOPG) substrate. The slow scan direction of all images is down the images. Image sizes are all 15 nm × 15 nm. The interfacial data was collected at differing applied potentials and open-circuit potential (OCP) (indicated in the figure). The OCPs for the [EMIm] Tf₂N + Li Tf₂N 0.1 wt/wt% and [EMIm] Tf₂N + [EMIm] Cl 0.1 wt/wt% systems were 0.30 V versus Pt and 0.42 V versus Pt, respectively. The slow scan direction of all images is down the images.
Figure 9.9 In situ STM images of the Au(1 1 1) surface obtained in the pure [Py_1,4] FAP (a, e), 0.1 M TaF₅/[Py_1,4] FAP (b, f), 0.1 M LiCl/[Py_1,4] FAP (c, g), and 0.1 M SiCl₄/[Py_1,4] FAP (d, h) during cathodic polarization.
Figure 9.10 (a) XPS survey spectrum of [OMIM] Tf₂N deposited on HOPG. (b) XPS detailed spectrum of the N1s core-level orbital.
Figure 9.11 XPS detailed spectra of the N1s core-level orbital of [Py_1,4] Tf₂N deposited on (a) a clean surface and (b) a Li precovered Cu surface.
Figure 9.12 UHV-STM images of [Py_1,4] FAP deposited on Au(1 1 1): (a) at room temperature (298 K, 20 nm × 20 nm), (b) at reduced temperature (210 K, 10 nm × 10 nm).

Chapter 10: Plasma Electrochemistry with Ionic Liquids

Figure 10.1 Positive space charge layer at the interface between a plasma and (a) a dielectric, (b) a metallic, and (c) an electrolytic wall with floating potential φ_w.
Figure 10.2 Different types of plasma reactors employing the use of an IL: (a) DC discharge with the IL as an integral part of a serial setup, (b) DC discharge with the IL as optional part of a parallel setup, (c) inductively coupled RF discharge with an electric circuit for electrochemical experiments independent from the plasma generating process.
Figure 10.3 Setup of the reproduced Gubkin experiment: silver is dissolved at the anode inside of the liquid electrolyte and reduced at the plasma–electrolyte interface; photograph of the laboratory experiment.
Figure 10.4 Experimental setups for different plasma (electro)chemical experiments: (a) DC setup of Klemenc, (b) setup for the recovery of metal from slags, and (c) vapor-phase electrolytic deposition setup of Ogumi et al.
Figure 10.5 Decomposition pathways of 1,1-butylmethylpyrrolidinium according to Ref. [51].
Figure 10.6 Decomposition pathways of 1-butyl-3-methylimidazolium according to Ref. [51].
Figure 10.7 Decomposition pathways of 1-butyl-3-methylimidazolium via a biradical transition state.
Figure 10.8 Schematic experimental setup for the deposition of metal nanoparticles by plasma electrochemical reduction of a metal salt dissolved in an ionic liquid at room temperature.
Figure 10.9 DC discharge over [BMIM][TfO].
Figure 10.10 Plasma electrochemical deposition of silver nanoparticles at the free surface of [BMIM][TfO].
Figure 10.11 SEM image of the silver nanoparticles.
Figure 10.12 TEM image and size distribution of the silver nanoparticles.
Figure 10.13 Ar/H₂ (3 : 1) plasma burning over Cu(CF₃SO₃)₂ dissolved in [EMIM][TfO] with a brown cloud and black deposits. The distance amounts to only 4.5 cm; thus, the plasma consists mostly of dark space (Faraday space).
Figure 10.14 HRSEM picture of the obtained palladium nanoparticles.
Figure 10.15 HRTEM/SAED picture of the palladium nanoparticles. The letters in the SAED picture represent the lattice indices: a = 111, b = 200, c = 220, d = 311.

Chapter 11: Impedance Spectroscopy

Figure 11.1 (a) Phase shift between AC voltage and current. (b) Illustration of the impedance in a complex plane.
Figure 11.2 Impedance and capacitance spectrum of a serial R_BulkC_DL equivalent circuit (R_Bulk = 10 kΩ and C_DL = 5 μF) in the complex planes.
Figure 11.3 The Randles circuit. The serial bulk resistance of the electrolyte is ignored for clarity.
Figure 11.4 Impedance spectrum of the Randles circuit with R_ct = 500 Ω, C_DL = 5 μF, and σ = 300 Ω s^−0.5.
Figure 11.5 Illustration of (a) two-electrode [5], (b) three-electrode [42], and (c) four-electrode [63] setups and their use for different kinds of electrochemical measurements.
Figure 11.6 Illustration of several cell designs used for EIS-based double-layer capacitance measurements. (a) A large cell with a Luggin-capillary-based RE; (b) a microcell used in the case of very small electrolyte volumes, which employs a vertical microreference electrode; and (c) a commercial cell for small electrolyte volumes with improved placement of the reference electrode (TSC surface, rhd instruments).
Figure 11.7 Visualization of the SSR as a function of the fit parameter vector x. There is a general tendency of fits to converge into local minima.
Figure 11.8 Example of initial parameter deduction directly from a measured impedance spectrum.
Figure 11.9 Illustration of the effect of proportional weighting on a fit. The inset shows a zoom into the high-frequency domain.
Figure 11.10 Lissajou plots of the system response to sinusoidal excitations. (a) Linear response with different phase angles. (b) Distortion caused by the presence of a 2nd harmonic response. (c) Distortion caused by the presence of a small noise signal with high frequency and small amplitude.
Figure 11.11 Differential capacitance versus electrode potential according to Korneyshev's mean-field lattice-gas model [95].
Figure 11.12 Capacitance spectrum of the [Pyrr_1,4]FAP–Au(1 1 1) interface in the complex capacitance plane.
Figure 11.13 Differential capacitance of the fast and slow capacitive processes at the [Pyrr_1,4]FAP|Au(1 1 1) interface, plotted versus the electrode potential E.
Figure 11.14 Differential capacitance of the fast capacitive process at the [EMIm]FAP|Au(1 1 1) interface, plotted versus the electrode potential E.
Figure 11.15 In situ STM images of the Au(1 1 1) surface in contact with [Pyrr_1,4]FAP at different electrode potentials.

Chapter 12: Technical Aspects

Figure 12.1.1 LSVs of (a) Co, (b) Ni, (c) Cu, and (d) Zn discs in Ethaline and BMIMCl at 70 °C with a sweep rate of 5 mV s.
Figure 12.1.2 Flow chart for the pretreatment of substrates before electrodeposition in ionic liquids.
Figure 12.1.3 AFM images of (a) aluminum and (b) copper etched for 20 s at 10 V in Ethaline (right side of image masked during experiment). (c) Depth profiles for Panels (a) and (b) are shown as dashed and solid lines, respectively.
Figure 12.2.1 Structures of all RTILs listed in Table 12.2.1.
Figure 12.2.2 Cyclic voltammograms for the oxidation of 5 mM ferrocene in $c012-math-089$ on a platinum microelectrode (diameter $c012-math-090$ ) at $c012-math-091$ . Reference electrode was a Pt wire inserted into $c012-math-092$ contained in a glass tube, separated by a Vycor frit. Preoxidation of the reference electrode took place for (a) 0 min, (b) 5 min, (c) 10 min, (d) 20 min, (e) 40 min, and (f) 20 min with 1 h “rest.”
Figure 12.2.3 Cyclic voltammograms for the oxidation of 5 mM ferrocene in $c012-math-093$ on a platinum microelectrode (diameter $c012-math-094$ ) at $c012-math-095$ . Reference electrode was an Ag wire inserted into $c012-math-096$ contained in a glass tube, separated by a Vycor frit. Preoxidation took place for (a) 0 min, (b) 5 min, (c) 10 min, and (d) 20 min.
Figure 12.2.4 Cyclic voltammograms for (a) the reduction of 12.5 mM benzoquinone (BQ) in $c012-math-097$ on a platinum microelectrode (diameter $c012-math-098$ ) at $c012-math-099$ and (b) the oxidation of 20 mM N,N,N′,N′-tetramethylphenylenediamine (TMPD) in $c012-math-100$ on a platinum electrode (diameter $c012-math-101$ ) at $c012-math-102$ .
Figure 12.2.5 Cyclic voltammetry of 20 mM TMPD in $c012-math-103$ on a platinum electrode (diameter $c012-math-104$ ) at $c012-math-105$ in the presence of 0% and 100% hydrogen.
Figure 12.2.6 Outline of components of $c012-math-106$ reference electrode, and the reference electrode inserted into a salt bridge compartment.
Figure 12.2.7 Cyclic voltammograms for the reduction of 84 mM AgTf in $c012-math-107$ on a platinum microelectrode (diameter $c012-math-108$ ) at scan rates of 200, 400, 700 mV s⁻¹ and 1, 2, 4, 7, 10 V s⁻¹. The pseudo-reference electrode used was a silver wire. (b) Cyclic voltammetry for the reduction of 84 mM AgTf in $c012-math-109$ on silver wire (diameter 0.5 mm) at $c012-math-110$ with $c012-math-111$ reference electrode as in Ref. [35].
Figure 12.3.1 Semi-industrial process-scale plant operating at OCAS in Ghent (a) with a 1 -m-long, 25-cm-diameter steel cathode (b) yielding a chromium morphology (c).
Figure 12.3.2 (a) Barrel plating pilot plant for coating screws with a Zn−Sn layer developed by Inasmet in San Sebastian. (b) Samples of Mg alloy coated with a Zn−Sn alloy by Protection des Metaux in Paris.
Figure 12.3.3 Immersion silver line at PW circuits (Leicester, UK) involving a nine tank systems, three of which contain ionic liquids.
Figure 12.3.4 Electropolishing bath (1300 L) operating at Anopol Ltd., (Birmingham, UK) based on an ethylene glycol:choline chloride eutectic.
Figure 12.3.5 A variety of pieces electropolished using a choline-based ionic liquid.
Figure 12.3.6 Recycling of ionic liquid (one ChCl:two ethylene glycol) used to electropolish stainless steel: (a) used liquid containing Fe, Cr, and Ni salts; (b) same as (a) with 1 equiv. v/v added water; (c) same as (b) after gravity filtration and subsequent removal of residual water by distillation.
Figure 12.4.1 Concept of sustainable use of process bath liquors in electroplating: recovery (rinsing and concentration), regeneration (concentration and purification), and reuse.
Figure 12.4.2 Samples of spent [BMP]Tf₂N electrolyte (a) directly after electrodeposition of Al and (b) stirred at 75 °C in nitrogen atmosphere.
Figure 12.4.3 Samples after mixing with water, showing phase separation.
Figure 12.4.4 Recovered ionic liquid phase ([BMP]Tf₂N) after regeneration.
Figure 12.4.5 Cyclic voltammograms of original and regenerated ionic liquid ([BMP]Tf₂N). The potential was determined versus Pt as quasi-reference electrode. Scan rate 5 mV s⁻¹.
Figure 12.5.1 Cyclic voltammogram of ultrapure [C₄mpyr]TFSI on Au(111) with v = 10 mV s⁻¹. The electrochemical window is 5.6 V. The reduction peaks C1–C3 are correlated with TFSI breakdown, which may be induced by ultralow amounts of water or other impurities.
Figure 12.5.2 The in situ STM picture evidences that the Au(111) surface near the open-circuit potential shows a worm-like surface pattern, likely due to interference between the gold surface and the [C₄mpyr] cation.
Figure 12.5.3 The quality of the STM picture is reduced strongly in the potential regime of the reduction peaks C1–C3 in [C₄mpyr]TFSI. The STM probes the breakdown of the TFSI, which may be induced by water and/or other impurities in the ultralow concentration regime.
Figure 12.5.4 (a) Cyclic voltammogram of [C₄mpyr]TFSI (with low amounts of Li impurities) on Au(111): the processes C5 and C6 are typical for deposition in the UPD and OPD regimes, respectively. (b) In situ STM of Au(111) before C5: flat gold surface. (c) In situ STM of Au(111) between C5 and C6: obviously Li deposition has occurred.
Figure 12.5.5 Cyclic voltammograms (10 mV s⁻¹) of [EMIM]TFSI (purified over silica) on Au(111), (a) 1st, (b) 7th, and (c) 15th cycles.
Figure 12.5.6 In situ STM pictures of [EMIM]TFSI (purified over silica) on Au(111): obviously, there is a surface film adsorbed initially, which can be reduced to a nice terrace-like deposit.

Chapter 13: Plating Protocols

Figure 13.1 SEM image of an Al layer electroplated on mild steel at 20 mA cm⁻².
Figure 13.2 The optical view of the cross section for an Al layer electroplated on mild steel at 20 mA cm⁻².
Figure 13.3 The optical view of the cross section for an Al layer electroplated on mild steel at 20 mA cm⁻² with significant adherence improvement by in situ electrochemical etching.
Figure 13.4 An optical photo of deposits manufactured from the employed ionic liquid. The employed liquid can also be used to electroplate Al on an uneven surface or even a screw, as shown in Figure 13.4. The in situ etching leads to Al layers all showing satisfactory adhesive qualities.
Figure 13.5 Photos showing (a) the dull finish at 0.5 V and (b) the bright finish at 1.0 V.
Figure 13.6 SEM images of (a) the dull finish at 0.5 V and (b) the bright finish at 1.0 V.
Figure 13.7 (a) SEM image of an about 10 µm aluminum layer electrodeposited galvanostatically on a mild steel substrate at −5 mA cm⁻². Inset: SEM image of higher magnification showing the excellence of the coating adhesion. (b) SEM image of the polished cross section of the deposited aluminum layer [2].
Figure 13.8 An optical photo of a deposited Al layer formed potentiostatically at −0.3 V (vs . Ae/Ae³⁺) in the upper phase of the mixture [C₂mim]NTf₂/6 M AlCl₃ at room temperature. Degreased in acetone in an ultrasonic bath, treated with dilute hydrochloric acid, and rinsed with distilled water.
Figure 13.9 SEM image of electrodeposited Al on mild steel formed potentiostatically at −0.75 V (vs Al) for 2 h in the upper phase of the mixture [C₄ mpyr]NTf₂/2 M AlCl₃ at 100 °C.
Figure 13.10 SEM image of electrodeposited Al on gold formed potentiostatically at −0.45 V (vs Al) for 2 h in the upper phase of the mixture [C₄ mpyr]NTf₂/1.6 M AlCl₃) at 100 °C.
Figure 13.11 XRD patterns of an electrodeposited Al layer obtained potentiostatically at −1.7 V for 2 h in the upper phase of the mixture [C₄ mpyr]NTf₂/1.6 M AlCl₃ at 100 °C on a glassy carbon substrate.
Figure 13.12 (a) SEM image of the electrodeposit formed potentiostatically on Pt in [C₄ mpyr]NTf₂ containing 0.25 M TaF₅ and 0.25 LiF at a potential of −1.8 V for 1 h at 200 °C. (b) XRD patterns of the deposited Ta layer.
Figure 13.13 SEM images showing the deposits gained from (a) choline chloride:ethylene glycol (1 : 2) + 0.3 M ZnCl₂ and (b) choline chloride:ethylene glycol (1 : 2) + 0.3 M $c013-math-001$ 1 molar equivalent ethylene diamine. Both experiments were carried out by applying a constant current density of 5 mA cm⁻² at 50 °C, without stirring for 60 min.
Figure 13.14 Ni deposit obtained from bulk electrodeposition of choline chloride/ethylene-glycol containing 1.14 mol dm⁻³ NiCl₂·6H₂O at 80 °C for 1 h on a nickel electrode at a current density of 1.5 A dm⁻³.

List of Tables

Synthesis of Ionic Liquids

Table 2.1.1 Physical data of selected ionic liquids
Table 2.2.1 Dependence of selected physicochemical properties (at 20 °C) of ionic liquids [EMIM]X on the anion X⁻
Table 2.2.2 A comparison of the relative hydrophobicity of eight ionic liquids
Table 2.3.1 Freezing temperature data for a variety of metal salts and amides when mixed with choline chloride in 2 : 1 ratio
Table 2.3.2 Viscosity and conductivity of a variety of ionic liquids at 298 K

Chapter 3: Physical Properties of Ionic Liquids for Electrochemical Applications

Table 3.1 Melting points (°C) of several salts
Table 3.2 Melting points (T_m) of a series of [Tf₂N]-type ILs
Table 3.3 Thermal properties of imidazolium-type ILs containing various anions
Table 3.4 Heat capacity and conductivity of ILs
Table 3.5 Viscosity of several ILs at room temperature (25 °C ± 1) and organic solvents (as a reference)
Table 3.6 Density of several ILs
Table 3.7 Refractive index of ILs
Table 3.8 The values of E_T(30) and $c03-math-071$ for some ILs
Table 3.9 Kamlet–Taft parameters for typical ILs
Table 3.10 Polarity of ILs determined by $c03-math-102$ and Nile red
Table 3.11 Distribution ratios between RTIL/aqueous phases
Table 3.12 Observed solubility constants (K_s) of inorganic salts in several ILs
Table 3.13 Distribution ratio for Hg²⁺ and Cd²⁺ in the mixed systems of water and TSIL 1 or TSIL 2
Table 3.14 Electrochemical windows for a variety of ILs
Table 3.15 Specific ionic conductivity and related properties of imidazolium salts at 25 °C
Table 3.16 Ionic conductivity (25°C) of amines neutralized by HBF₄
Table 3.17 Ionic conductivity of ILs containing lithium salts at 25 °C
Table 3.18 Ionic conductivity of zwitterions containing equimolar lithium salts
Table 3.19 Physical properties and diffusion coefficients of ILs at 30 °C

Chapter 5: Electrodeposition of Alloys

Table 5.1 Metal alloys that have been electrodeposited from ionic liquids.

Chapter 6: Electrodeposition of Semiconductors from Ionic Liquids

Table 6.1 Semiconductors that have been deposited in ionic liquids

Chapter 8: Nanostructured Materials

Table 8.1.1 Effect of different additives on the crystallite size (electrolyte: 63 mol % absolute dry AlCl₃, 37 mol % [C₂mim]Cl, DC: 5 mA cm^{− 2}, additive concentration: 4 wt %)
Table 8.1.2 The influence of different process parameters on the nanostructure of aluminum deposits
Table 8.1.3 Saturation magnetization, relative remanence, and coercivity for different crystallite sizes of nanostructured iron

Chapter 11: Impedance Spectroscopy

Table 11.1 Impedance response of common electrical and electrochemical elements

Chapter 12: Technical Aspects

Table 12.1 A cross section of the different types of reference electrodes that have been used by various researchers in a range of different RTILs

All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.

The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at <http://dnb.d-nb.de>.

All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.

List of Contributors

Andrew P. Abbott

University of Leicester

Department of Chemistry

University Road

Leicester LE1 7RH

Rob Atkin

University of Newcastle

Priority Research Centre for Advanced Fluids and Interfaces

Callaghan Campus, University Drive

Callaghan, NSW 2308

Australia

Marco Balabajew

University of Marburg

Department of Chemistry

Hans-Meerwein-Strasse 4

35032 Marburg

Germany

Tom Beyersdorff

IoLiTec Ionic Liquids Technologies GmbH

Salzstraße 184

74076 Heilbronn

Germany

Natalia Borisenko

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Timo Carstens

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Po-Yu Chen

Kaohsiung Medical University

Department of Medicinal and Applied Chemistry

100 Shih-Chuan 1st Road

80708 Kaohsiung

Taiwan

Sherif Zein El Abedin

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

National Research Centre

Physical Chemistry Department, Electrochemistry and Corrosion Laboratory

El Bohouth Street 33, Dokki

12622 Giza

Egypt

Aaron Elbourne

University of Newcastle

Priority Research Centre for Advanced Fluids and Interfaces

Callaghan Campus

University Drive

Callaghan, NSW 2308

Australia

Frank Endres

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Gero Frisch

Technische Universität Bergakademie Freiberg

Institut für Anorganische Chemie

Leipziger Straße 29

09596 Freiberg

Germany

René Gustus

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Jennifer Hartley

Technische Universität Bergakademie Freiberg

Institut für Anorganische Chemie

Leipziger Straße 29

09596 Freiberg

Germany

Rolf Hempelmann

Universät des Saarlandes

Transferzentrum Nano-Elektrochemie

Campus Dudweiler Am Markt – Zeile 3

66125 Saarbrücken

Germany

Jürgen Janek

Justus-Liebig-Universität Gießen

Physikalisch-Chemisches Institut

Heinrich-Buff-Ring 17

35392 Gießen

Germany

Wrya Karim

Monash University, School of Chemistry

Wellington Road

Clayton, VIC 3800

Australia

Abhishek Lahiri

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Hua Li

University of Newcastle

Priority Research Centre for Advanced Fluids and Interfaces

Callaghan Campus, University Drive

Callaghan, NSW 2308

Australia

Yao Li

Center for Composite Materials

Harbin Institute of Technology

150001 Harbin

China

Douglas R. Macfarlane

Monash University

School of Chemistry

Wellington Road

Clayton, VIC 3800

Australia

Katy J. McKenzie

University of Leicester

Department of Chemistry

University Road

Leicester LE1 7RH

Sebastian A. Meiss

Justus-Liebig-Universität Gießen

Physikalisch-Chemisches Institut

Heinrich-Buff-Ring 17

35392 Gießen

Germany

Harald Natter

Universät des Saarlandes

Transferzentrum Nano-Elektrochemie

Campus Dudweiler Am Markt – Zeile 3

66125 Saarbrücken

Germany

Hiroyuki Ohno

Tokyo University of Agriculture and Technology

Graduate School of Engineering

2-24 Nakacho

Koganei

Tokyo 184-8588

Japan

Will Pitner

Merck KG&A

PLS R&D LSS Ionic Liquids 1

Frankfurter Str 250

64271 Darmstadt

Germany

Manuel Pölleth

Justus-Liebig-Universität Gießen

Physikalisch-Chemisches Institut

Heinrich-Buff-Ring 17

35392 Gießen

Germany

Jennifer M. Pringle

Deakin University, Geelong

Institute for Frontier Materials, Australian Centre of Excellence for Electromaterials Science

Burwood Campus, Burwood Highway

Burwood, VIC 3125

Australia

Giridhar Pulletikurthi

Clausthal University of Technology

Institute of Electrochemistry

Arnold-Sommerfeld-Street 6

38678 Clausthal-Zellerfeld

Germany

Marcus Rohnke

Justus-Liebig-Universität Gießen

Physikalisch-Chemisches Institut

Heinrich-Buff-Ring 17

35392 Gießen

Germany

Bernhard Roling

University of Marburg

Department of Chemistry

Hans-Meerwein-Strasse 4

35032 Marburg

Germany

Karl S. Ryder

University of Leicester

Department of Chemistry

University Road

Leicester LE1 7RH

Thomas J. S. Schubert

IoLiTec Ionic Liquids Technologies GmbH

Salzstraße 184

74076 Heilbronn

Germany

I-Wen Sun

National Cheng Kung University

Department of Chemistry

1 Ta-Hsueh Road

Tainan 70101

Taiwan

Jorg Thöming

UFT

Section of Chemical Engineering

Universität Bremen, Leobener Str.

28359 Bremen

Germany

Jens Wallauer

University of Marburg

Department of Chemistry

Hans-Meerwein-Strasse 4

35032 Marburg

Germany

Urs Welz-Biermann

New Business-Chemicals/Ionic Liquids (NB-C)

Merck KG&A, NB-C, D1/311

Frankfurter Str 250

64293 Darmstadt

Germany

Jiupeng Zhao

School of Chemistry and Chemical Engineering

Harbin Institute of Technology

150001 Harbin

China

Dr. Daniel Waterkamp

bluesign technologies ag Moevenstrasse 18

9015 St.GallenSwitzerland