Ion Exchange Membranes Design, Preparation, and Applications

A comprehensive introduction to the electro-membrane technologies of the future

An ion exchange membrane is a polymer-based membrane which can be permeable by some ions in a solution while blocking others, making them ideal for processes such as water desalination, salt concentration control, clean production and?given their electrical conductivity?power generation and energy storage etc. Recent advances have given rise to new electro-membrane processes that promise drastically to expand the applications of this technology. Scientists in both research and industry will increasingly need to draw on these membranes in vital ways with strongly positive potential environmental impact.

Ion Exchange Membranes summarizes recent research into these membranes and electro-membrane processes before moving to an overview of the historical background. It then attends in detail to cutting-edge fabrication technologies and the most recent areas of use. The result is a comprehensive introduction to the design, fabrication, and applications of these increasingly essential membranes.

Ion Exchange Membranes readers will also find:

• In-depth treatment of industrial-scale applications
• Detailed discussion of topics including side-chain engineering, polyacylation, superacid-catalyst polymerization, and more
• Analysis of electro-membrane processes such as alkaline membrane water electrolysis, solar-driven water splitting, and many more

Ion Exchange Membranes is ideal for membrane scientists, materials scientists, inorganic chemists, polymer chemists, and researchers and engineers in a variety of fields working with ion exchange membranes and electro-membrane processes.

Preface xi

1 Overview of Ion Exchange Membranes 1

1.1 Definition and Classifications 1

1.2 Profile of IEMs 1

1.3 Preparation of IEMs 7

1.4 Applications 10

1.5 Potentials 11

References 13

2 Fundamentals and Characterizations 21

2.1 Donnan Equilibrium 21

2.2 Membrane Potential 22

2.3 Transference Number 24

2.4 Diffusion Coefficient and Ion Permeability 25

2.5 Ion Flux and Permselectivity 26

2.6 Area Resistance 27

2.7 Concentration Polarization 29

2.8 Limiting Current Density and Current–Voltage Curves 29

2.9 Water Transport 32

2.10 Membrane Scaling and Fouling 34

2.11 Zeta Potential 35

2.12 Other Conventional Characterization 38

2.12.1 Conductivity 38

2.12.2 Ion Exchange Capacity 39

2.12.3 Water Uptake and Swelling Ratio 40

2.12.4 Mechanical Strength 40

References 41

3 Side-chain Engineering for Ion Exchange Membrane Preparation 45

3.1 Principles of Side-chain Engineering 45

3.1.1 Inspiration of Nafion 45

3.1.2 Microphase Separation of Grafted Polymers 47

3.2 Construction of Side-chain Architecture 47

3.2.1 Design of Side-chain CEMs 47

3.2.1.1 Design of Side-chain CEMs with Similar Nafion Structures 47

3.2.1.2 Design of Side-chain CEMs with Grafted Structures 61

3.2.2 Design of Side-chain AEMs 64

3.2.2.1 Design of Side-chain AEMs with Similar Nafion Structures 64

3.2.2.2 Design of Side-chain AEMs with Grafted Structures 75

3.2.2.3 Design of Functional Groups for Side-chain AEMs 76

3.3 Construction of the Cross-linking Side Chain 81

3.4 Construction of Hyperbranched Networks 83

3.5 Construction of Dynamic Transfer Regions 84

3.6 Construction of Cation–Dipole Interactions 88

References 92

4 Polyacylation for Ion Exchange Membrane Preparation 105

4.1 Principle of Polyacylation 108

4.2 Types of Acylation Reactions 109

4.2.1 Acylation of Alcohols 111

4.2.2 Acylation of Amines 112

4.2.3 Acylation of Enols 114

4.2.4 Acylation of Carboxylic Acids 116

4.2.5 Acylation of Ketones 116

4.2.6 Acylation of Amides 118

4.2.7 Acylation of Sulfonamides 119

4.2.8 Polyacylation of Polymers 121

4.2.9 Advantages and Limitations of Polyacylation as a Synthetic Approach 123

4.2.10 Polyacylation and Polymers 124

4.3 Perylene-based Polyimides 125

4.3.1 Traditional Route 125

4.3.2 Polyacylation Route 127

4.3.3 Synthesis of Perylene-based Polyimide-based Ion Exchange Membranes 131

4.3.4 Perylene and Polyimide-based CEMs 135

4.3.5 Perylene and Polyimide-based AEMs 138

4.4 Polyacylation of SPEK-based IEMs 140

4.4.1 Polyacylation of SPEK-based CEMs 140

4.4.2 Polyacylation of SPEK-based AEMs 144

4.5 Polyacylation/Polyacylated Crown Ether IEMs 146

4.5.1 Acylation of Crown Ether 146

4.5.2 Poly-Crown Ether-based AEM 147

4.5.3 Poly-crown Ether-based Noncharged Selective Membrane (PCENS-M) 153

4.6 Conclusion 156

4.6.1 Challenges/Opportunities for Further Development 156

4.6.2 Outlook for the Future of Polyacylation in Membrane Research 157

References 157

5 Superacid–Catalyst Polymerization for IEMs Preparation 169

5.1 Definition and Types of Superacid 169

5.2 Principle of Superacid Catalyst 172

5.3 Superacid-catalyzed Reaction for Polymer Synthesis 175

5.4 Superacid-catalyst Polymerization for IEM Preparation 179

5.5 Others 213

References 215

6 Microporous Polymers for IEM Preparation 219

6.1 Ion Transport Behavior in Nanospace-confined Membranes 219

6.2 Principle of Microporous Polymers 220

6.3 IEMs Derived from Microporous Polymers 225

6.3.1 Positively Charged Microporous Polymers 225

6.3.2 Negatively Charged Microporous Polymers 232

6.3.2.1 Hydrolysis of Dibenzodioxin-based Microporous Polymers 233

6.3.2.2 Amidoxime of Dibenzodioxin-based PIMs 233

6.3.2.3 Post-sulfonation of PIMs or Bottom-up Approach 234

6.4 Conclusion and Outlook 239

References 240

7 In Situ Polymerization for IEM Preparation 245

7.1 Conventional Methods for IEM Preparation 245

7.2 Semi-interpenetrating Polymer Network 246

7.3 Pore Filling 250

7.4 Solvent-free Strategy 253

7.5 In Situ Polymerization 255

References 256

8 Special IEMs Preparation 261

8.1 Metal–Organic Framework Membranes 261

8.1.1 Introduction 261

8.1.2 Structural Properties of MOFs 261

8.1.2.1 Structural Diversity 261

8.1.2.2 Structural Tunability 262

8.1.2.3 High Stability 264

8.1.3 Preparation of MOF Membranes 265

8.1.3.1 UiO-66-NH₂ Membrane 266

8.1.3.2 UiO-66-SO₃H Membrane 268

8.1.3.3 UiO-66(Zr/Ti)-NH₂/Polyamide Mixed Matrix Membrane 268

8.1.3.4 PolyMOF Membrane 271

8.2 Porous Organic Cage Membranes 272

8.2.1 Introduction 272

8.2.2 Structural Properties of POCs 274

8.2.3 Preparation of POC Membranes 276

8.2.3.1 POC Membranes of Versatile Channels 276

8.2.3.2 High Ion-Permselective CC3 Membrane 281

8.3 Covalent Organic Framework Membranes 285

8.3.1 Introduction 285

8.3.2 Design Strategies of the COF Structure 286

8.3.2.1 Pore Structure Design 288

8.3.2.2 Pore Surface Engineering 288

8.3.3 Preparation of COF Membranes 292

8.3.3.1 COF Membrane with Sub-2-nm Channels 292

8.3.3.2 Cationic COF Membrane 296

8.3.3.3 Self-Standing COF Membrane 300

8.4 Electro-Nanofiltration Membranes 305

8.4.1 Introduction 305

8.4.2 The Preparation of ENMs 306

8.4.3 The Performance of ENMs 307

8.5 Conclusion and Perspective 314

References 315

9 Applications 327

9.1 Diffusion Dialysis (DD) 327

9.1.1 The Basic Theory of Diffusion Dialysis 327

9.1.1.1 High-performance Diffusion Dialysis Membranes 328

9.1.2 Diffusion Dialysis Components 330

9.1.3 Diffusion Dialysis Application Field 331

9.1.3.1 Recovery of Waste Acid 331

9.1.3.2 Alkali Recovery 333

9.2 Reverse Electrodialysis (RED) 334

9.2.1 Basic Theory of RED 336

9.2.2 The Main Components of RED 338

9.2.2.1 Ion Exchange Membrane 339

9.2.2.2 Spacers 341

9.2.2.3 Electrode System 342

9.3 Donnan Dialysis 343

9.3.1 Basic Theory of Donnan Dialysis 344

9.3.1.1 The Parameters Affecting Donnan Dialysis 346

9.4 Electrodialysis (ED) 347

9.5 Application of ED 349

9.5.1 Desalination 349

9.5.2 Concentration 351

9.5.3 The Influencing Parameters on ED Concentration 351

9.5.3.1 Approaches to Improve the Concentration on ED 352

9.5.4 Resource Conversion 353

9.5.5 CO₂ Capture 355

9.6 Electrodialysis with Bipolar Membranes (BMED) 356

9.6.1 The Basic Theory of Bipolar Membranes 358

9.6.2 Application of the BMED Process 360

9.6.2.1 The Production of Alkali 360

9.6.2.2 The Production of Acid 362

9.6.2.3 Production of CO                   Conversion 364

9.6.3 The Limitations of BMED 365

9.7 Electrodialysis Metathesis (EDM) 367

9.7.1 Application of the EDM Process 367

9.7.1.1 The Production of Ionic Liquid 367

9.7.1.2 High-Salinity Wastewater Conversion 369

9.7.1.3 The Production of Potassium Fertilizers 370

9.8 Ion-Distillation Technology 372

9.9 Fuel Cells 378

9.10 Water Electrolysis 384

9.11 Industrial Applications 386

9.11.1 Acid Recovery Using Diffusion Dialysis 386

9.11.2 Resource Recovery Using Electrodialysis 389

9.11.3 Clean Production Using Bipolar Membrane Electrodialysis 395

References 396

Index 413

Tongwen Xu, PhD, is Chair Professor of Chemistry Engineering at the University of Science and Technology China (USTC). He has held visiting positions at the University of Tokyo and the Tokyo Institute of Technology, Japan, and served as a Brain-Pool Professor of Korea at the Gwangju Institute of Science and Technology, Korea. He has published extensively on ion exchange membranes and related subjects over the course of a research career spanning more than a quarter century, and is the holder of more than 100 patents.

Yaoming Wang, PhD, is a professor at the Applied Chemistry Department in the University of Science and Technology of China (USTC). He received his Ph.D. degree from USTC in 2011 under the direction of Prof. Tongwen Xu. He was appointed as an assoicated professor in Nov 2013 after two years postdoctoral research in USTC, and was promoted to professor in Dec 2021. His research interests are ion-exchange membrane and electro-membrane related processes such as electrodialysis, bipolar membrane electrodialysis, ion-capture electrodialysis, membrane intergration process, etc. He has published over 100 peer-reviewed journal papers, with an H-index of 36.