Chapter 01 Removal of Surface Contaminants Using Ionic Liquids 1Copyright © 2013 Elsevier Inc. All rights reserved.

FIGURE 1.1 Current and potential applications of ionic liquids (MALDI-TOF-MS = Matrix-assisted laser desorption/ionization time- of-flight mass spectrometry; GC = Gas chromatography). Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.2

FIGURE 1.2 Structures of typical cations and anions used for making ionic liquids. R is an alkyl group or an aryl group. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.3

FIGURE 1.3 Physical appearance of ionic liquids. On the left is methyl-tri- n -butylammonium dioctyl sulfosuccinate with a melting point around 313 K. On the right is 1-butyl-3-methyl imidazolium (diethylene glycol monomethyl ether) sulfate which is liquid at room temperature. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.4

FIGURE 1.4 A room temperature ionic liquid compared with common table salt. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.5

FIGURE 1.5 Metal-based ionic liquids exhibit a wide range of colors. The liquids are from left to right: copper-based compound, cobalt-based compound, manganese-based compound, iron-based compound, nickel-based compound, and vanadium-based compound. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.6

FIGURE 1.6 Protic ionic liquids are located within a solvent spectrum from pure ionic liquids to molecular liquids. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.7

FIGURE 1.7 Examples of triphasic mixtures of ionic liquid, water, and an organic compound. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.8

FIGURE 1.8 The phase diagram for mixtures of [EMIM]Cl and AlCl 3. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.9

FIGURE 1.9 Melting points for the [C n mim]Cl ionic liquids as a function of the alkyl chain length. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.10

FIGURE 1.10 Melting point phase diagram for the [C n mim][PF 6 ] ionic liquids as a function of the alkyl chain length. The melting transitions are shown from the crystalline phase (closed squares), glassy materials (open squares) and the clearing transition (closed circles) 2. LC is the liquid crystal state. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.11

FIGURE 1.11 Melting point phase diagram for the [C n mim][BF 4 ] ionic liquids as a function of the alkyl chain length. The melting transitions are shown from the crystalline phase (closed squares), glassy materials (open squares) and the clearing transition (closed circles). LC is the liquid crystal state. Rajiv Kohli Chapter 1 - Removal of Surface Contaminants Using Ionic Liquids Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 1 – 63 Copyright © 2013 Elsevier Inc. All rights reserved.12