Responsive Membranes and Materials

Dibakar Bhattacharyya is the University of Kentucky Alumni Professor of Chemical Engineering and a Fellow of the AIChE. He received his Ph.D. from the Illinois Institute of Technology, M.S. from Northwestern University, and B.S. from Jadavpur University. He is the Co-Founder of the Center for Membrane Sciences at the University of Kentucky. He has published over 180 refereed journal articles and book chapters, and five U.S. Patents. At the Dr. Bhattacharyya was honored for his contributions in the area of Functionalized Membranes at the 2007 NAMS Annual Meeting, and he was the main plenary speaker at the SIMPAM 2009 Membrane Conference in Brazil. Sylvia Daunert is the Gill Eminent Professor of Analytical and Biological Chemistry at the University of Kentucky. Her research is in the area of Bioanalytical Chemistry, at the interface between Analytical Chemistry, Molecular Biology, and Bioengineering. Ranil Wickramasinghe is Professor at Colorado State University. His research focuses on the development of membranes and membrane separation processes for bioseparations, water treatment and biofuels applications. Thomas Schäfer is Ikerbasque Research Professor at the Institute of Polymer Materials (POLYMAT) of the University of the Basque Country in San Sebastián, Spain.

Preface xv

List of Contributors xxi

1 Oligonucleic Acids (“Aptamers”) for Designing Stimuli-Responsive Membranes 1
Veli Cengiz O¨ zalp, Mar´ýa Bele´n Serrano-Santos and Thomas Scha¨fer

1.1 Introduction 1

1.2 Aptamers – Structure, Function, Incorporation, and Selection 4

1.3 Characterization Techniques for Aptamer-Target Interactions 7

1.3.1 Measuring Overall Structural Changes of Aptamers Using QCM-D 8

1.3.2 Measuring Overall Structural Changes of Aptamers Using DPI 13

1.4 Aptamers – Applications 17

1.4.1 Electromechanical Gates 17

1.4.2 Stimuli-Responsive Nucleic Acid Gates in Nanoparticles 17

1.4.3 Stimuli-Responsive Aptamer Gates in Nanoparticles 20

1.4.4 Stimuli-Responsive Aptamer-Based Gating Membranes 22

1.5 Outlook 25

Acknowledgements 26

References 26

2 Emerging Membrane Nanomaterials – Towards Natural Selection of Functions 31
Mihail Barboiu

2.1 Introduction 31

2.2 Ion-Pair Conduction Pathways in Liquid and Hybrid Membranes 32

2.3 Dynamic Insidepore Resolution Towards Emergent Membrane Functions 36

2.4 Dynameric Membranes and Materials 39

2.4.1 Constitutional Hybrid Materials 39

2.4.2 Dynameric Membranes Displaying Tunable Properties on Constitutional Exchange 41

2.5 Conclusion 46

Acknowledgements 47

References 47

3 Carbon Nanotube Membranes as an Idealized Platform for Protein Channel Mimetic Pumps 51
Bruce Hinds

3.1 Introduction 51

3.2 Experimental Understanding of Mass Transport Through CNTs 56

3.2.1 Ionic Diffusion and Gatekeeper Activity 57

3.2.2 Gas and Fluid Flow 57

3.3 Electrostatic Gatekeeping and Electro-osmotic Pumping 59

3.3.1 Biological Gating 62

3.4 CNT Membrane Applications 63

3.5 Conclusion and Future Prospects 66

Acknowledgements 67

References 67

4 Synthesis Aspects in the Design of Responsive Membranes 73
Scott M. Husson

4.1 Introduction 73

4.2 Responsive Mechanisms 74

4.3 Responsive Polymers 75

4.3.1 Temperature-Responsive Polymers 75

4.3.2 Polymers that Respond to pH, Ionic Strength, Light 76

4.4 Preparation of Responsive Membranes 77

4.5 Polymer Processing into Membranes 78

4.5.1 Solvent Casting 78

4.5.2 Phase Inversion 78

4.6 In Situ Polymerization 78

4.6.1 Radiation-Based Methods 78

4.6.2 Interpenetrating Polymer Networks (IPNs) 79

4.7 Surface Modification Using Stimuli-Responsive Polymers 79

4.8 “Grafting to” Methods 81

4.8.1 Physical Adsorption – Non-covalent 81

4.8.2 Chemical Grafting – Covalent 81

4.8.3 Surface Entrapment – Non-covalent, Physically Entangled 82

4.9 “Grafting from” – a.k.a. Surface-Initiated Polymerization 83

4.9.1 Photo-Initiated Polymerization 83

4.9.2 Atom Transfer Radical Polymerization 85

4.9.3 Reversible Addition-Fragmentation Chain Transfer Polymerization 87

4.9.4 Other Grafting Methods 91

4.9.5 Summary of “Grafting from” Methods 91

4.10 Future Directions 91

References 92

5 Tunable Separations, Reactions, and Nanoparticle Synthesis in Functionalized Membranes 97
Scott R. Lewis, Vasile Smuleac, Li Xiao and D. Bhattacharyya

5.1 Introduction 97

5.2 Membrane Functionalization 98

5.2.1 Chemical Modification 98

5.2.2 Surface Initiated Membrane Modification 101

5.2.3 Cross-Linked Hydrogel (Pore Filled) Membranes 102

5.2.4 Layer by Layer Assemblies 103

5.3 Applications 104

5.3.1 Water Flux Tunability 104

5.3.2 Tunable Separation of Salts 109

5.3.3 Charged-Polymer Multilayer Assemblies for Environmental Applications 113

5.4 Responsive Membranes and Materials for Catalysis and Reactions 115

5.4.1 Iron-Functionalized Responsive Membranes 116

5.4.2 Responsive Membranes for Enzymatic Catalysis 127

Acknowledgements 132

References 132

6 Responsive Membranes for Water Treatment 143
Qian Yang and S. R. Wickramasinghe

6.1 Introduction 143

6.2 Fabrication of Responsive Membranes 144

6.2.1 Functionalization by Incubation in Liquids 145

6.2.2 Functionalization by Incorporation of Responsive Groups in the Base Membrane 145

6.2.3 Surface Modification of Existing Membranes 148

6.3 Outlook 158

References 159

7 Functionalization of Polymeric Membranes and Feed Spacers for Fouling Control in Drinking Water Treatment Applications 163
Colleen Gorey, Richard Hausman and Isabel C. Escobar

7.1 Membrane Filtration 163

7.2 Fouling 165

7.3 Improving Membrane Performance 168

7.3.1 Plasma Treatment 168

7.3.2 Ultraviolet (UV) Irradiation 170

7.3.3 Membrane Modification by Graft Polymerization 171

7.3.4 Ion Beam Irradiation 176

7.4 Design and Surface Modifications of Feed Spacers for Biofouling Control 178

7.5 Conclusion 180

Acknowledgements 181

References 181

8 Pore-Filled Membranes as Responsive Release Devices 187
Kang Hu and James Dickson

8.1 Introduction 187

8.2 Responsive Pore-Filled Membranes 188

8.3 Development and Characterization of PVDF-PAA Pore-Filled pH-Sensitive Membranes 190

8.3.1 Membrane Gel Incorporation (Mass Gain) 191

8.3.2 Membrane pH Reversibility 191

8.3.3 Membrane Water Flux as pH Varied from 2 to 7.5 191

8.3.4 Effects of Gel Incorporation on Membrane Pure Water Permeabilities at pH Neutral and Acidic 195

8.3.5 Estimation and Calculation of Pore Size 198

8.4 pH-Sensitive Poly(Vinylidene Fluoride)-Poly(Acrylic Acid) Pore-Filled Membranes for Controlled Drug Release in Ruminant Animals 201

8.4.1 Determination of Membrane Diffusion Permeability (PS) for Salicylic Acid 202

8.4.2 Applicability of the Fabricated Pore-Filled Membranes on the Salicylic Acid Release and Retention 205

References 207

9 Magnetic Nanocomposites for Remote Controlled Responsive Therapy and in Vivo Tracking 211
Ashley M. Hawkins, David A. Puleo and J. Zach Hilt

9.1 Introduction 211

9.1.1 Nanocomposite Polymers 211

9.1.2 Magnetic Nanoparticles 212

9.2 Applications of Magnetic Nanocomposite Polymers 212

9.2.1 Thermal Actuation 213

9.2.2 Thermal Therapy 218

9.2.3 Mechanical Actuation 220

9.2.4 In Vivo Tracking and Applications 224

9.3 Concluding Remarks 224

References 224

10 The Interactions between Salt Ions and Thermo-Responsive Poly (N-Isopropylacrylamide) from Molecular Dynamics Simulations 229
Hongbo Du and Xianghong Qian

10.1 Introduction 229

10.2 Computational Details 230

10.3 Results and Discussion 232

10.4 Conclusion 238

Acknowledgements 240

References 240

11 Biologically-Inspired Responsive Materials: Integrating Biological Function into Synthetic Materials 243
Kendrick Turner, Santosh Khatwani and Sylvia Daunert

11.1 Introduction 243

11.2 Biomimetics in Biotechnology 245

11.3 Hinge-Motion Binding Proteins 249

11.4 Calmodulin 250

11.5 Biologically-Inspired Responsive Membranes 251

11.6 Stimuli-Responsive Hydrogels 253

11.7 Micro/Nanofabrication of Hydrogels 255

11.8 Mechanical Characterization of Hydrogels 256

11.9 Creep Properties of Hydrogels 257

11.10 Conclusion and Future Perspectives 258

Acknowledgements 258

References 258

12 Responsive Colloids with Controlled Topology 269
Jeffrey C. Gaulding, Emily S. Herman and L. Andrew Lyon

12.1 Introduction 269

12.2 Inert Core/Responsive Shell Particles 270

12.3 Responsive Core/Responsive Shell Particles 275

12.4 Hollow Particles 281

12.5 Janus Particles 286

12.6 Summary 292

References 293

13 Novel Biomimetic Polymer Gels Exhibiting Self-Oscillation 301
Ryo Yoshida

13.1 Introduction 301

13.2 The Design Concept of Self-Oscillating Gel 303

13.3 Aspects of the Autonomous Swelling–Deswelling Oscillation 303

13.4 Design of Biomimetic Actuator Using Self-Oscillating Polymer and Gel 306

13.4.1 Ciliary Motion Actuator (Artificial Cilia) 306

13.4.2 Self-Walking Gel 307

13.4.3 Theoretical Simulation of the Self-Oscillating Gel 307

13.5 Mass Transport Surface Utilizing Peristaltic Motion of Gel 308

13.6 Self-Oscillating Polymer Chains and Microgels as “Nanooscillators” 309

13.6.1 Solubility Oscillation of Polymer Chains 309

13.6.2 Self-Flocculating/Dispersing Oscillation of Microgels 310

13.6.3 Viscosity Oscillation of Polymer Solution and Microgel Dispersion 311

13.6.4 Attempts of Self-Oscillation under Acid- and Oxidant-Free Physiological Conditions 311

13.7 Conclusion 312

References 312

14 Electroactive Polymer Soft Material Based on Dielectric Elastomer 315
Liwu Liu, Zhen Zhang, Yanju Liu and Jinsong Leng

14.1 Introduction to Electroactive Polymers 315

14.1.1 Development History 316

14.1.2 Classification 316

14.1.3 Electronic Electroactive Polymers 316

14.1.4 Ionic Electroactive Polymers 318

14.1.5 Electroactive Polymer Applications 318

14.1.6 Application of Dielectric Elastomers 318

14.1.7 Manufacturing the Main Structure of Actuators Using EAP Materials 327

14.1.8 The Current Problem for EAP Materials and their Prospects 329

14.2 Materials of Dielectric Elastomers 330

14.2.1 The Working Principle of Dielectric Elastomers 330

14.2.2 Material Modification of Dielectric Elastomer 331

14.2.3 Dielectric Elastomer Composite 334

14.3 The Theory of Dielectric Elastomers 336

14.3.1 Free Energy of Dielectric Elastomer Electromechanical Coupling System 336

14.3.2 Special Elastic Energy 339

14.3.3 Special Electric Field Energy 341

14.3.4 Incompressible Dielectric Elastomer 342

14.3.5 Model of Several Dielectric Elastomers 342

14.4 Failure Model of a Dielectric Elastomer 356

14.4.1 Electrical Breakdown 357

14.4.2 Electromechanical Instability and Snap-Through Instability 357

14.4.3 Loss of Tension 358

14.4.4 Rupture by Stretching 359

14.4.5 Zero Electric Field Condition 359

14.4.6 Super-Electrostriction Deformation of a Dielectric Elastomer 359

14.5 Converter Theory of Dielectric Elastomer 361

14.5.1 Principle for Conversion Cycle 361

14.5.2 Plane Actuator 362

14.5.3 Spring-Roll Dielectric Elastomer Actuator 364

14.5.4 Tube-Type Actuator 365

14.5.5 Film-Spring System 369

14.5.6 Energy Harvester 372

14.5.7 The Non-Linear Vibration of a Dielectric Elastomer Ball 376

14.5.8 Folded Actuator 377

References 379

15 Responsive Membranes/Material-Based Separations: Research and Development Needs 385
Rosemarie D. Wesson, Elizabeth S. Dow and Sonya R. Williams

15.1 Introduction 385

15.2 Water Treatment 386

15.3 Biological Applications 387

15.4 Gas Separation and Additional Applications 388

References 389

Index 395