Nanochemistry A Chemical Approach to Nanomaterials

Geoffrey A. Ozin and Andre C. Arsenault Chemistry Department, University of Toronto, Canada

RSC Publishing

Contents

List of Acronyms xxv

Teaching (Nano)Materials xxix

Learning (Nano)Materials xxxi

About the Authors xxxiii

Acknowledgements xxxvii

Nanofood for Thought - Thinking about Nanochemistry, Nanoscience, Nanotechnology and Nanosafety xxxix Chapter 1 Nanochemistry Basics 1

1.1 Materials Self-Assembly 1 1.2 Big Bang to the Universe 2 1.3 Why Nano? 2 1.4 What do we Mean by Large and Small Nanomaterials? 3 1.5 Do it Yourself Quantum Mechanics 4 1.6 What is Nanochemistry? 5 1.7 Molecular vs. Materials Self-Assembly 5 1.8 What is Hierarchical Assembly? 6 1.9 Directing Self-Assembly 6 1.10 Supramolecular Vision 7 1.11 Geneology of Self-Assembling Materials 8 1.12 Unlocking the Key to Porous Solids 11 1.13 Learning from Biominerals - Form is Function 14 1.14 Can you Curve a Crystal? 16 1.15 Patterns, Patterns Everywhere 17 1.16 Synthetic Creations with Natural Form 18 1.17 Two-Dimensional Assemblies 20 1.18 SAMs and Soft Lithography 23 1.19 Clever Clusters 24

XV

XVI Contents

1.20 Extending the Prospects of Nanowires 26 1.21 Coercing Colloids 27 1.22 Mesoscale Self-Assembly 31 1.23 Materials Self-Assembly of Integrated Systems 32 1.24 References 33 Nanofood for Thought - Nanochemistry, Genealogy Materials Self-Assembly, Length Scales 45

Chapter 2 Chemical Patterning and Lithography 49 2.1 Soft Lithography 49 2.2 What are Self-Assembled Monolayers? 50 2.3 The Science and Art of Soft Lithography 52 2.4 Patterning Wettability? 54 2.5 Condensation Figures 55 2.6 Microlens Arrays 56 2.7 Nanoring Arrays 58 2.8 Patterning the Solid State 59 2.9 Primed for Printing Polymers 61 2.10 Beyond Molecules - Transfer Printing of Thin Films 63 2.11 Electrically Contacting SAMS 64 2.12 SAM Crystal Engineering 66 2.13 Learning from Nature's Biocrystal Engineering 68 2.14 Colloidal Microsphere Patterns 71 2.15 Switching SAM Function 71 2.16 Patterning by Photocatalysis 73 2.17 Reversibly Switching SAMs 74 2.18 Electrowettability Switch 76 2.19 Sweet Chips 77 2.20 All Fall Down in a Row Lithography 79 2.21 References 80 Nanofood for Thought - Soft Lithography, SAMs, Patterning 89

Chapter 3 Layer-by-Layer Self-Assembly 95 3.1 Building One Layer at a Time 95 3.2 Electrostatic Superlattices 95 3.3 Organic Polyelectrolyte Multilayers 97 3.4 Layer-by-Layer Smart Windows 97 3.5 How Thick is Thin? 99 3.6 Assembling Metallopolymers 99 3.7 Directly Imaging Polyelectrolyte Multilayers 100 3.8 Polyelectrolyte-Colloid Multilayers 101 3.9 Graded Composition LbL Films 103 3.10 LbL MEMS 104 3.11 Trapping Active Proteins 106 3.12 Layering on Curved Surfaces 106 3.13 Crystal Engineering of Oriented Zeolite Film 108

Contents xvu

3.14 Zeolite-Ordered Multicrystal Arrays 110 3.15 Crosslinked Crystal Arrays 111 3.16 Layering with Topological Complexity 112 3.17 Patterned Multilayers 113 3.18 Non-Electrostatic Layer-by-Layer Assembly 115 3.19 Low Pressure Layers 116 3.20 Layer-by-Layer Self-Limiting Reactions 117 3.21 References 118 Nanofood for Thought - Designer Monolayers, Multilayers, Materials Fiatland 126

Chapter 4 Nanocontact Printing and Writing - Stamps and Tips 131

4.1 Sub-100 nm Soft Lithography 131 4.2 Extending Microcontact Printing 131 4.3 Putting on the Pressure 133 4.4 Defect Patterning - Topologically Directed Etching 135 4.5 Below 50 nm Nanocontact Printing 136 4.6 Nanocontact Writing - Dip Pen Nanolithography 137 4.7 DPNof Silicon 138 4.8 DPN on Glass 139 4.9 Nanoscale Writing on Seminconductor Nanowires 140 4.10 Sol-Gel DPN 141 4.11 Soft Patterning of Hard Magnets 142 4.12 Writing Molecular Recognition 143 4.13 DPN Writing Protein Recognition Nanostructures 145 4.14 Patterning Bioconstructions 145 4.15 Eating Patterns - Enzyme DPN 147 4.16 Electrostatic DPN 148 4.17 Electrochemical DPN 148 4.18 SPM Nano-Electrochemistry 149 4.19 Beyond DPN - Whittling Nanostructures 151 4.20 Combi Nano - DPN Combinatorial Libraries 151 4.21 Nanoplotters 153 4.22 Nanoblotters 154 4.23 Scanning Probe Contact Printing (SP-CP) 155 4.24 Dip Pen Nanolithography Stamp Tip - Beyond DPN CP 157 4.25 Best of Both Worlds 157 4.26 The Nanogenie is out of the Bottle 158 4.27 References 158 Nanofood for Thought ~ Sharper Chemical Patterning Tools 164

Chapter 5 Nanorod, Nanotube, Nanowire Self-Assembly 167 5.1 Building Block Assembly 167 5.2 Templating Nanowires 167

Wil l Contents

5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25 5.26 5.27 5.28 5.29 5.30 5.31 5.32

5.33 5.34 5.35 5.36 5.37 5.38 5.39 5.40 5.41 5.42 5.43 5.44 5.45 5.46 5.47

Modulated Diameter Gold Nanorods 168 Modulated Composition Nanorods 170 Barcoded Nanorod Orthogonal Self-Assembly 173 Self-Assembling Nanorods 176 Magnetic Nanorods Bunch Up 177 Magnetic Nanorods and Magnetic Nanoclusters 178 An Irresistable Attraction for Biomolecules 181 Hierarchically Ordered Nanorods 183 Nanorod Devices 184 Nanotubes from Nanoporous Templates 186 Layer-by-Layer Nanotubes from Nanorods 188 Synthesis of Single Crystal Semiconductor Nanowires 189 Vapor-Liquid-Solid Synthesis of Nanowires 189 What Controls Nanowire-Oriented Growth? 191 Supercritical Fluid-Liquid-Solid Synthesis 191 Nanowire Quantum Size Effects 193 Zoo of Nanowire Compositions and Architectures 195 Single-Source Precursors 195 Manipulating Nanowires 196 Crossed Semiconductor Nanowires - Smallest LED 199 Nanowire Diodes and Transistors 201 Nanowire Sensors 201 Catalytic Nanowire Electronics 203 Nanowire Heterostructures 204 Longitudinal Nanowire Superlattices 206 Axial Nanowire Heterostructures 207 Nanowires Branch Out 209 Coaxially Gated Nanowire Transistor 209 Vertical Nanowire Field Effect Transistors 212 Integrated Metal-Semiconductor Nanowires - Nanoscale Electrical Contacts 215 Photon-Driven Nanowire Laser 216 Electrically Driven Nanowire Laser 218 Nanowire UV Photodetectors 220 Simplifying Complex Nanowires 220 Nanowire Casting of Single-Crystal Nanotubes 222 Solution-Phase Routes to Nanowires 223 Spinning Nanowire Devices 226 Hollow Nanofibers by Electrospinning 227 Carbon Nanotubes 229 Carbon Nanotube Structure and Electrical Properties 229 Gone Ballistic 231 Carbon Nanotube Nanomechanics 233 Carbon Nanotube Chemistry 233 Carbon Nanotubes All in a Row 236 Carbon Nanotube Photonic Crystal 238

Contents xix

5.48 Putting Carbon Nanotubes Exactly Where You Want Them 240

5.49 The Nanowire Pitch Challenge 242 5.50 Tntegrated Nanowire Nanoelectronics 244 5.51 A Small Thought at the End of a Large Chapter 246 5.52 References 246 Nanofood for Thought - Wires, Rods, Tubes, Low Dimensionality 260

Chapter 6 Nanocluster Self-Assembly 265 6.1 Building-Block Assembly 265 6.2 When is a Nanocluster a Nanocrystal or Nanoparticle? 266 6.3 Synthesis of Capped Semiconductor Nanoclusters 266 6.4 Electrons and Holes in Nanocluster Boxes 268 6.5 Watching Nanoclusters Grow 270 6.6 Nanocrystals in Nanobeakers 271 6.7 Nanocluster Semiconductor Alloys and Beyond 273 6.8 Nanocluster Phase Transformation 274 6.9 Capped Gold Nanoclusters - Nanonugget Rush 275 6.10 Alkanethiolate Capped Nanocluster Diagnostics 277 6.11 Periodic Table of Capped Nanoclusters 278 6.12 There's Gold in Them Thar Hills! 278 6.13 Water-Soluble Nanoclusters 279 6.14 Capped Nanocluster Architectures and Morphologies 281 6.15 Alkanethiolate Capped Silver Nanocluster Superlattice 282 6.16 Crystals of Nanocrystals 284 6.17 Beyond Crystal of Nanocrystals - Binary Nanocrystal

Superlattices 285 6.18 Capped Magnetic Nanocluster Superlattice - High

Density Data Storage Materials 286 6.19 Alloying Core-Shell Magnetic Nanoclusters 287 6.20 Soft Lithography of Capped Nanoclusters 288 6.21 Organizing Nanoclusters by Evaporation 289 6.22 Electroluminescent Semiconductor Nanoclusters 289 6.23 Füll Color Nanocluster-Polymer Composites 291 6.24 Capped Semiconductor Nanocluster Meets Biomolecule 293 6.25 Nanocluster DNA Sensors - Besting the Best 296 6.26 Semiconductor Nanoclusters Extend and Branch Out 297 6.27 Branched Nanocluster Solar Cells 299 6.28 Tetrapod of Tetrapods - Towards Inorganic Dendrimers 300 6.29 Golden Tips - Making Contact with Nanorods 301 6.30 Flipping a Nanocluster Switch 303 6.31 Photochromic Metal Nanoclusters 304 6.32 Carbon Nanoclusters - Buckyballs 306 6.33 Building Nanodevices with Buckyballs 307 6.34 Carbon Catalysis with Buckyball 308

Contents

6.35 References 309 Nanofood for Thought - Nanoclusters, Nanocrystals, Quantum Dots, Quantum Site Effects 320

Chapter 7 Microspheres - Colors from the Beaker 325 7.1 Nature's Photonic Crystals 325 7.2 Photonic Crystals 325 7.3 Photonic Semiconductors 327 7.4 Defects, Defects, Defects 328 7.5 Computing with Light 328 7.6 Color Tunability 330 7.7 Transferring Nature's Photonic Crystal Technology to

the Chemistry Laboratory 330 7.8 Microsphere Building Blocks 331 7.9 Silica Microspheres 331 7.10 Latex Microspheres 332 7.11 Multi-Shell Microspheres 332 7.12 Basics of Microsphere Seif-Assembly 333 7.13 Microsphere Seif-Assembly - Crystals and Films 334 7.14 Colloidal Crystalline Fluids 336 7.15 Beyond Face Centered Cubic Packing of Microspheres 337 7.16 Templates - Confinement and Epitaxy 338 7.17 Photonic Crystal Fibers 340 7.18 Photonic Crystal Marbles 340 7.19 Optical Properties of Colloidal Crystals - Combined

Bragg-Snell Laws 343 7.20 Basic Optical Properties of Colloidal Crystals 343 7.21 How Perfect is Perfect? 345 7.22 Cracking Controversy 346 7.23 Synthesizing a Füll Photonic Band Gap 348 7.24 Writing Defects 349 7.25 Getting Smart with Planar Defects 350 7.26 Switching Light with Light 353 7.27 Internal Light Sources 353 7.28 Photonic Inks 354 7.29 Color Oscillator 357 7.30 Photonic Crystal Sensors 357 7.31 Colloidal Photonic Crystal Solar Cell 359 7.32 Thermochromic Colloidal Photonic Crystal Switch 360 7.33 Liquid Crystal Photonic Crystal 361 7.34 Encrypted Colloidal Crystals 363 7.35 Gazing into the Photonic Crystal Ball 365 7.36 References 365 Nanofood for Thought - Colloidal Assembly, Colloidal Crystals, Colloidal Crystal Devices, Structural Color 373

Contents xxi

Chapter 8 Microporous and Mesoporous Materials from Soft Building Blocks 379

8.1 Escape from the Zeolite Prison 379 8.2 A Periodic Table of Materials Filled with Holes 380 8.3 Modular Seif-Assembly of Microporous Materials 381 8.4 Hydrogen Storage Coordination Frameworks 383 8.5 Overview and Prospects of Microporous Materials 384 8.6 Mesoscale Soft Building Blocks 385 8.7 Micelle Versus Liquid Crystal Templating Paradox 387 8.8 Designing Function into Mesoporous Materials 387 8.9 Tuning Length Scales 388 8.10 Mesostructure and Dimensionality 390 8.11 Mesocomposition - Nature of Precursors 390 8.12 Mesotexture 391 8.13 Periodic Mesoporous Silica-Polymer Hybrids 392 8.14 Guests in Mesopores 393 8.15 Capped Nanocluster Meets Surfactant Mesophase 394 8.16 Marking Time in Mesostructured Silica - New Approach

to Optica! Data Storage 396 8.17 Sidearm Mesofunctionalization 397 8.18 Organics in the Backbone 398 8.19 Mesomorphology - Films, Interfaces, Mesoepitaxy 400 8.20 Stand Up and Be Counted 402 8.21 Mesomorphology - Spheres, Other Shapes 404 8.22 Mesomorphology - Patterned Films, Soft Lithography,

Micromolding 406 8.23 Mesomorphology - Morphosynthesis of Curved Form 408 8.24 Chiral Surfactant Micelles - Chiral Mesoporous Silica 410 8.25 Mesopore Replication 413 8.26 Mesochemistry and Topological Defects 414 8.27 Mesochemistry - Synthesis in "Intermediate" Dimensions 415 8.28 References 418 Nanofood for Thought - Soft Blocks Template Hard Precursors, Holey Materials 430

Chapter 9 Self-Assembling Block Copolymers 435 9.1 Polymers, Polymers Everywhere in Nanochemistry 435 9.2 Block Copolymer Self-Assembly - Chip Off the Old

Block 435 9.3 Nanostructured Ceramics 437 9.4 Nano-objects 439 9.5 Block Copolymer Thin Films 439 9.6 Electrical Ordering 442 9.7 Spatial Confinement of Block Copolymers 442 9.8 Nanoepitaxy 444

XX11 Contents

9.9 Block Copolymer Lithography 444 9.10 Decorating Block Copolymers 446 9.11 A Case of Wettability 447 9.12 Nanowires from Block Copolymers 449 9.13 Making Micelles 451 9.14 Assembling Inorganic Polymers 453 9.15 Harnessing Rigid Rods 453 9.16 Supramolecular Assemblies 455 9.17 Supramolecular Mushrooms 456 9.18 Structural Color from Lightscale Block Copolymers 458 9.19 Block Copolypeptides 459 9.20 Block Copolymer Biofactories 461 9.21 References 462 Nanofood for Thought - Block Copolymer Seif-Assembling Nanostructures 468

Chapter 10 Biomaterials and Bioinspiration 473 10.1 Nature did it First 473 10.2 To Mimic or to Use? 474 10.3 Faux Fossils 475 10.4 Nature's Siliceous Sculptures 476 10.5 Ancient to Modern Synthetic Morphology 477 10.6 Biomimicry 478 10.7 Biomineralization and Biomimicry Analogies 479 10.8 Learning from Nature 481 10.9 Viral Cage Directed Synthesis of Nanoclusters 482 10.10 Viruses that Glitter 483 10.11 Polynucleotide Directed Nanocluster Assembly 484 10.12 DNA Coded Nanocluster Chains 485 10.13 Building with DNA 487 10.14 Bacteria Directed Materials Self-Assembly 489 10.15 Using a Virus that is Benign, to Align 491 10.16 Magnetic Spider Silk 492 10.17 Protein S-Layer Masks 493 10.18 Morphosynthesis - Inorganic Materials with

Complex Form 496 10.19 Echinoderm vs. Block Copolymers 498 10.20 Fishy Top-Down Photonic Crystals 499 10.21 Aluminophosphates Shape Up 501 10.22 Better Bones Through Chemistry 502 10.23 Mineralizing Nanofibers 504 10.24 Biological Lessons in Materials Design 505 10.25 Surface Binding Through Directed Evolution 505 10.26 Nanowire Evolution 508 10.27 Biomolecular Motors - Nanomachines Everywhere 508

Contents xxm

10.28 How Biomotors Work 510 10.29 Kinesin - Walk Along 512 10.30 ATPase - Biomotor Nanopropellors 515 10.31 (Bio)Inspiration 516 10.32 References 517 Nanofood for Thought - Organic Matrix, Biomineralization, Biomimetics, Bioinspiration 527

Chapter 11 Self-Assembly of Large Building Blocks 531 11.1 Self-assembling Supra-micron Shapes 531 11.2 Synthesis Using the "Capillary Bond" 532 11.3 Crystallizing Large Polyhedral-Shaped Building Blocks 533 11.4 Self-Assembling 2D and 3D Electrical Circuits and

Devices 533 11.5 Crystallizing Micron-Sized Planar Building Blocks 534 11.6 Polyhedra with Patterned Faces that Autoconstruct 536 11.7 Large Sphere Building Blocks Self-Assemble

into 3D Crystals 540 11.8 Synthetic MEMS? 541 11.9 Magnetic Self-Assembly 541 11.10 Dynamic Self-Assembly 543 11.11 Autonomous Self-Assembly 544 11.12 Self-Assembly and Synthetic Life 547 11.13 References 548 Nanofood for Thought - Static and Dynamic, Capillary Bond, Shape Assembly 550

Chapter 12 Nano and Beyond 553 12.1 Assembling the Future 553 12.2 Microfluidic Computing 554 12.3 Fuel Cells - Hold the Membrane 554 12.4 Curved Prints 554 12.5 Beating the Ink Diffusion Dilemma 555 12.6 Tip of the Pyramid 556 12.7 Biosensing Membranes 556 12.8 Crossing Nanowires 556 12.9 Complete Crystallographic Control 557 12.10 Down to the Wire 557 12.11 Shielded Nanowires 558 12.12 Writing 3D Nanofluidic and Nanophotonic Networks 559 12.13 Break-and-Glue Transistor Assembly 560 12.14 Turning Nanostructures Inside-out 560 12.15 Confining Spheres 560 12.16 Escape from the Silica and Polystyrene Prison 562 12.17 Smart Dust 562 12.18 Light Writing for Light Guiding 562

XXIV Contents

12.19 12.20 12.21 12.22 12.23 12.24 12.25 12.26

Nanoring Around the Collar A Meso Rubbed Right Fungus with the Midas Touch Self-assembled Electronics Gears Sink Their Teeth into the Interface Materials Retro-assembly Matter that Matters - Materials of the "Next Kind" References

Nanofood for Thought - Nano Potpourri

563 563 564 565 565 566 568 571 574

Chapter 13 Nanochemistry Nanolabs 579

Appendix A: Origin of the Term "Self-Assembly" 585

Appendix B : Cytotoxicity of Nanoparticles 589

Appendix C: Walking Macromolecules Through Colloidal Crystals 593

Appendix D: Patterning Nanochannel Alumina

Membranes With Single Channel Resolution 597

Appendix E : Muscle Powered Nanomachines 599

Appendix F : Bacteria Power 603

Appendix G: Chemically Driven Nanorod Motors 607 Subject Index 611