C. Br&hignac P. Houdy M. Lahmani (Eds.) Nanomaterials and Nanochemistry

With 461 Figures and 26 Tables

R 5

EUROPEAN MATERIALS RESEARCH SOCIETY ei Springer Contents

Part I Basic Principles and Fundamental Properties

1 Size Effects on Structure and Morphology of Free or Supported Nanoparticles C. Henry 3 1.1 Size and Confinement Effects 3 1.1.1 Introduction 3 1.1.2 Fraction of Surface Atoms 3 1.1.3 Specific Surface Energy and Surface Stress 4 1.1.4 Effect on the Lattice Parameter 5 1.1.5 Effect on the Phonon Density of States 8 1.2 Nanoparticle Morphology 8 1.2.1 Equilibrium Shape of a Macroscopic Crystal 8 1.2.2 Equilibrium Shape of Nanometric Crystals 10 1.2.3 Morphology of Supported Particles 17 References 32

2 Structure and Phase Transitions in Nanocrystals J.-C. Niepce, L. Pizzagalli 35 2.1 Introduction 35 2.2 Crystalline Phase Transitions in Nanocrystals 39 2.2.1 Phase Transitions and Grain Size Dependence 39 2.2.2 Elementary Thermodynamics of the Grain Size Dependence of Phase Transitions 40 2.2.3 Influence of the Surface or Interface on Nanocrystals 42 2.2.4 Modification of Transition Barriers 44 2.3 Geometric Evolution of the Lattice in Nanocrystals 46 2.3.1 Grain Size Dependence 46 2.3.2 Theory 47 2.3.3 Influence of the Nanocrystal Surface or Interface on the Lattice Parameter 50 XII Contents

2.3.4 Is There a Continuous Variation of the Crystal State Within Nanocrystals? 51 References 53 3 Thermodynamics and Solid—Liquid Transitions P. Labastie, F. Calvo 55 3.1 Size Dependence of the Solid—Liquid Transition 56 3.1.1 From the Macroscopic to the Nanometric 56 3.1.2 From Nanoparticles to Molecules 64 3.2 Thermodynamics of Very Small Systems 67 3.2.1 General Considerations 67 3.2.2 Non-Equivalence of the Gibbs Ensembles 68 3.2.3 Dynamically Coexisting Phases 69 3.2.4 Stability of an Isolated Particle. Thermodynamic Equilibrium 73 3.3 Evaporation: Consequences and Observation 74 3.3.1 Statistical Theories of Evaporation 74 3.3.2 Link with the Solid—Liquid Transition. Numerical Results 79 3.3.3 Experimental Investigation of Evaporation 80 3.3.4 Beyond Unimolecular Evaporation 81 3.3.5 Toward the Liquid—Gas Transition 82 References 86

4 Modelling and Simulating the Dynamics of Nano-Objects A. Pimpinelli 89 4.1 Introduction 89 4.2 Free Clusters of Atoms. Molecular Dynamics Simulations 90 4.3 Evolution of Free and Supported Nanoclusters Toward Equilibrium. Kinetic Monte Carlo Simulations 93 References 97

Part II Physical and Chemical Properties an the Nanoscale

5 Magnetism in Nanomaterials D. Givord 101 5.1 Introduction 101 5.2 Magnetism in Matter 102 5.2.1 Magnetic Moment 102 5.2.2 Magnetic Order 105 5.2.3 Magnetocrystalline Anisotropy 108 5.3 Magnetisation Process and Magnetic Materials 110 5.3.1 Energy of the Demagnetising Field. Domains and Walls 111 5.3.2 The Magnetisation Process 112 5.3.3 Magnetic Materials 115 Contents XIII

5.4 Magnetism in Small Systems 116 5.4.1 Magnetic Moments in Clusters 116 5.4.2 Magnetic Order in Nanoparticles 119 5.4.3 Magnetic Anisotropy in Clusters and Nanoparticles 120 5.5 Magnetostatics and Magnetisation Processes in Nanoparticles 121 5.5.1 Single-Domain Magnetic Particles 121 5.5.2 Thermal Activation and Superparamagnetism 122 5.5.3 Coherent Rotation in Nanoparticles 123 5.5.4 From Thermal Activation to the Macroscopic Tunnel Effect 124 5.6 Magnetism in Coupled Nanosystems 126 5.6.1 Exchange-Coupled Nanocrystals. Ultrasoft Materials and Enhanced Remanence 126 5.6.2 Coercivity in Nanocomposites 128 5.6.3 Exchange Bias in Systems of Ferromagnetic Nanoparticles Coupled with an Antiferromagnetic Matrix 130 References 132

6 Electronic Structure in Clusters and Nanoparticles F. Spiegelman 135 6.1 Introduction 135 6.2 Liquid-Drop Model 139 6.3 Methods for Calculating Electronic Structure 141 6.3.1 Born—Oppenheimer Approximation. Surface Potential 142 6.3.2 Ab Initio Calculation of Electronic Structure 144 6.3.3 Density Functional Theory 147 6.3.4 Charge Analysis 149 6.3.5 Approximate and Semi-Empirical Descriptions 150 6.3.6 Energy Bands and Densities of States 152 6.4 Applications to Some Typical Examples 154 6.4.1 Metallic Nanoparticles 154 6.4.2 Molecular Clusters 162 6.4.3 Tonic and Ionocovalent Clusters 170 6.4.4 Covalent Systems 175 6.5 Valence Changes 178 6.5.1 Transitions with Size 178 6.5.2 Transitions with Stoichiometry 179 6.6 Nanotub es 182 6.7 Prospects 185 References 188

7 Optical Properties of Metallic Nanoparticles F. Valide 197 7.1 Optical Response for Free Clusters and Composite Materials 198 XIV Contents

7.2 Optical Response in the Quasi-Static Approximation: Nanospheres 199 7.3 Dielectric Constant of a Metal: Nanometric Size Effect 203 7.4 Surface Plasmon Resonance in the Quasi-Static Approximation: Nanospheres 207 7.5 Surface Plasmon Resonance: Quantum Effects for Small Sizes (D < 5 nm) 211 7.6 General Case for Nanospheres: The Mie Model 213 7.7 Non-Spherical or Inhomogeneous Nanoparticles in the Quasi-Static Model 216 7.7.1 Shape Effects: Ellipsoids 216 7.7.2 Structure Effects: Core–Shell System 217 7.8 Optical Response of a Single Metal Nanoparticle 219 7.9 Electromagnetic Field Enhancement: Applications 221 7.9.1 Nonlinear Optical Response 221 7.9.2 Time-Resolved Spectroscopy 222 7.9.3 Local Enhancement of Raman Scattering: SERS 223 7.10 Conclusion 224 References 226

8 Mechanical and Nanomechanical Properties C. Tromas, M. Verdier, M. Fivel, P. Aubert, S. Labdi, Z.-Q. Feng, M. Zei, P. Joli 229 8.1 Macroscopic Mechanical Properties 229 8.1.1 Introduction 229 8.1.2 Elastic Properties 229 8.1.3 Hardness 231 8.1.4 Ductility 234 8.1.5 Numerical Modelling 236 8.2 Nanomechanical Properties 238 8.2.1 Experimentation 238 8.2.2 Computer Modelling 254 References 265 9 S up erplast icity T. Rouxel 269 9.1 Introduction 269 9.2 Mechanism 270 9.3 Superplastic Nanostructured Materials 276 9.4 Industrial Applications 277 References 280 Contents XV

10 Reactivity of Metal Nanoparticles J.-C. Bertolini, J.-L. Rousset 281 10.1 Size Effects 282 10.1.1 Structural Properties 282 10.1.2 Electronic Pfoper-Hes 286 10.1.3 Reactivity in Chemisorption and Catalysis of Monometallic Nanoparticles 288 10.2 Support Effects 293 10.3 Alloying Effects 295 10.3.1 Effect of Surface Segregation 296 10.3.2 Geometric Effects 297 10.3.3 Electronic Effects 298 10.4 Preparation and Implementation in the Laboratory and in Industry 299 References 302

11 Inverse Systems — Nanoporous Solids J. Patarin, 0. Spalla, F. Di Renzo 305 11.1 Introduction 305 11.2 Nomenclature: The Main Families of Porous Materials 305 11.3 Zeolites and Related Microporous Solids. Definition and Structure 307 11.4 Ordered Mesoporous Solids 309 11.5 Disordered Nanoporous Solids 311 References 314

12 Inverse Systems — Confined Fluids: Phase Diagram and Metastability E. Charlaix, R. Denoyel 315 12.1 Displacement of First Order Transitions: Evaporation and Condensation 315 12.1.1 Adsorption Isotherms 315 12.1.2 Capillary Condensation 317 12.1.3 Capillary Pressure and the Kelvin Radius 319 12.1.4 Non-Wetting Fluid 320 12.1.5 Perfectly Wetting Fluid 320 12.1.6 Hysteresis, Metastability and Nucleation 322 12.2 Melting—Solidification 325 12.3 Modification of the Critical Temperature 329 12.4 Ultraconfinement: Microporous Materials 331 References 334 XVI Contents

13 Supramolecular Chemistry: Applications and Prospects N. Solladie, J.-F. Nierengarten 335 13.1 From Molecular to Supramolecular Chemistry 335 13.2 Molecular Recognition 335 13.3 Anionic Coordination Chemistry and Recognition of Anionic Substrates 338 13.4 Multiple Recognition 338 13.5 Applications 341 13.6 Prospects 343 References 344

14 Nanocomposites: The End of Compromise H. Van Damme 347 14.1 Composites and Nanocomposites 347 14.2 Introduction to Polymers 351 14.2.1 Ideal Chains 352 14.2.2 The Glass Transition 354 14.2.3 Entropie Elasticity 357 14.3 Nanofillers 359 14.3.1 Clays 359 14.3.2 Carbon Nanotubes 363 14.4 Strengthening and Permeability Control: Models 364 14.4.1 Strengthening: Increasing the Modulus 364 14.4.2 Impermeability: Reducing the Diffusivity 367 14.5 Strengthening and Permeability of Nanocomposites: Facts and Explanations 369 14.5.1 Strengthening: Successes and Failures 369 14.5.2 Impermeability 376 14.5.3 Dimensional Stability 377 14.5.4 Fire Resistance 379 14.6 Conclusion 379 References 380

Part III Synthesis of Nanomaterials and Nanoparticles

15 Specific Features of Nanoscale Growth J. Livage, D. Roux 383 15.1 Introduction 383 15.2 Thermodynamics of Phase Transitions 383 15.3 Dynamics of Phase Transitions 385 15.3.1 Thermodynamics of Spinodal Decomposition 386 15.3.2 Thermodynamics of NucleationGrowth 388 15.4 Size Control 389 15.5 Triggering the Phase Transition 391 Contents XVII

15.6 Application to Solid Nanoparticles 392 15.6.1 Controlling Nucleation 392 15.6.2 Controlling Growth 393 15.6.3 Controlling Aggregation. Stability of Colloidal Dispersions 393 15.7 Breaking Matter into Pieces 393 References 394

16 Gas Phase Synthesis of Nanopowders Y. Champion 395 16.1 Introduction 395 16.2 The Need for Gas State Processing 397 16.3 Main Stages of Gas Phase Synthesis 400 16.4 Spontaneous Condensation of Nanoparticles: Homogeneous Nucleation 401 16.5 Undesirable Post-Condensation Effects and Control of the Nanometric State 408 16.5.1 Why Do These Effects Occur? 409 16.5.2 Particle Growth by Gas Condensation 410 16.5.3 Coalescent Coagulation 411 16.6 Vapour Formation and the Production of Nanopowders 416 16.6.1 Physical Processes 416 16.6.2 Chemical Processing: Laser Pyrolysis 424 16.7 Conclusion 426 References 426

17 Synthesis of Nanocomposite Powders by Gas–Solid Reaction and by Precipitation C. Laurent 429 17.1 Introduction 429 17.2 Synthesis of Nanocomposite Powders by Gas—Solid Reactions 430 17.2.1 Synthesis of Intergranular Nanocomposite and Nano—Nano Composite Powders 430 17.2.2 Synthesis of Intragranular and Hybrid Nanocomposite Powders 433 17.3 Conclusion 438 References 438

18 Colloidal Methods and Shape Anisotropy D. Ingert 441 18.1 Introduction 441 18.2 Surfactants 442 18.3 Reverse Micelles: Spherical Nanoreactors 445 18.4 Factors Affecting Shape Control 448 18.4.1 Effect of the Colloidal Template an Shape Control 448 XVIII Contents 18.4.2 Effect of Anions on Nanocrystal Growth 449 18.4.3 Effect of Molecular Adsorption on Nanocrystalline Growth 451 18.5 Conclusion 452 References 453 19 Mechanical Milling E. Gaffet, G. Le Car 455 19.1 Introduction 455 19.1.1 Mechanosynthesis 455 19.1.2 Mechanical Activation 455 19.2 Ball Mills 456 19.3 Mechanisms 458 19.3.1 Reducing Cristallite Sizes 458 19.3.2 Parameters Relevant to Mechanical Alloying and Activation 459 19.3.3 Mechanics of Mechanical Alloying 461 19.4 Materials and Their Applications 462 19.4.1 Mechanical Alloying 462 19.4.2 Mechanical Activation 462 19.5 Shaping and Densifying Nanomaterials 464 19.5.1 Standard Processes 464 19.5.2 Mechanically-Activated Field-Activated Pressure-Assisted Synthesis (MAFAPAS) 464 19.6 Severe Plastic Deformation (SPD) 466 19.6.1 High-Pressure Torsion (HPT) 467 19.6.2 Equal Channel Angular Pressing (ECAP) 468 19.7 Bulk Mechanical Alloying 468 19.8 Synthesis of Nanocomposites by Extrusion, Drawing, and Embossing 468 References 469 20 Supercritical Fluids A. Taleb 473 20.1 Definition 473 20.2 Physicochemical Properties 475 20.2.1 Solubility 475 20.2.2 Viscosity 477 20.2.3 Diffusion 477 20.2.4 Thermal Conductivity 479 20.3 Applications 479 20.3.1 Purification and Extraction 479 20.3.2 Synthesis 480 References 484 Contents XIX

Part IV Fabrication of Nanostructured Bulk Materials and Nanoporous Materials

21 Bulk Nanostructured Materials Obtained by Powder Sintering F. Bernard, J.-C. Niepce 489 21.1 Sintering 489 21.1.1 Definition 489 21.1.2 The Physical Phenomena of Sintering 489 21.1.3 Different Sintering Conditions 489 21.1.4 Preserving Nanostructure During Sintering 491 21.2 Spark Plasma Sintering (SPS) 491 21.2.1 Basic Principle 491 21.2.2 Advantages of the SPS Process 493 21.2.3 Illustrations in the Field of Nanomaterials 493 References 495 22 Self-Assemblr of Nanomaterials at Macroscopic Scales A. Courty 497 22.1 Fabrication of Nanomaterials 498 22.2 2D and 3D Nanomaterial Structures 500 22.2.1 Depositing Nanomaterials an a Solid Substrate 500 22.2.2 Forces Inducing Self-Organisation 502 22.2.3 Crystal Structure of 2D and 3D Nanomaterials 508 22.3 Conclusion 513 References 513 23 Assemblies of Magnetic Nanoparticles J. Richardi 515 23.1 Magnetic Properties of Nanoparticle Assemblies 515 23.2 Structure of Magnetic Nanoparticle Assemblies Deposited Without Field 519 23.3 Structure of Magnetic Nanoparticle Assemblies Deposited with Field 523 23.3.1 Perpendicular Field 523 23.3.2 Parallel Field 526 References 527 24 Nanostructured Coatings J. -P. Riviere 529 24.1 Methodology for Malring Superhard Nanostructured Coatings 530 24.1.1 Multilayers with Nanometric Period 530 24.1.2 Nanocomposites 532 24.2 Methods of Synthesis 536 24.2.1 General Principles 536 XX Contents 24.2.2 Plasma-Activated Chemical Vapour Deposition (PACVD) . 539 24.2.3 Physical Vapour Deposition by Sputtering and Cathodic Arc 540 24.2.4 PVD by Ion Beam Sputtering 544 References 546 25 Dispersion in Solids D. Babonneau 549 25.1 Chemical Methods 550 25.1.1 Synthesis of Doped Glasses 550 25.1.2 Sol–Gel Method 551 25.2 Physical Methods 554 25.2.1 Ion Implantation 555 25.2.2 Vapour Deposition and Sputtering Methods 559 25.2.3 Pulsed Laser Deposition 562 25.2.4 Low Energy Cluster Beam Deposition (LECBD) 563 References 565 26 Nanoporous Media J. Patarin, 0. Spalla, F. Di Renzo 569 26.1 Introduction 569 26.2 Synthesis of Crystalline Microporous Solids 569 26.2.1 Methods of Synthesis 569 26.2.2 The Crystallisation Process Exemplified by Zeolites 571 26.2.3 Main Organic Structure-Directing Agents Used to Synthesise Crystalline Microporous Solids 573 26.2.4 Role of Inorganic Cations and Organic Species 573 26.2.5 Organic Species and the Template Effect 574 26.2.6 Porosity of Zeolites and Related Solids 576 26.2.7 Applications of Zeolitic Materials 577 26.3 Synthesis of Ordered Mesoporous Solids 579 26.3.1 Methods of Synthesis 579 26.3.2 Definition and Role of the Surfactant 581 26.3.3 Mechanisms for the Formation of MCM-41 Phase 582 26.3.4 Characteristics of Mesoporous Silicas Obtained in the Presence of Amphiphilic Molecules 588 26.3.5 Structural Characterisation of Nanoporous Solids by X-Ray and Neutron Scattering 589 26.4 Conclusion 593 References 593 27 Molecular Imprinting V. Dufaud, L. Bonneviot 597 27.1 Introduction 597 27.2 Fundamental Considerations 598 27.2.1 General Principles 598 Contents XXI

27.2.2 Role of Complexation Sites During the Imprinting Process . 599 27.2.3 Structure and Properties of the Polymer Matrix 602 27.3 Procedures and Methods for Molecular Imprinting 603 27.3.1 Imprinted Organic Polymers 603 27.3.2 Imprinted Inorganic Matrices 604 27.4 Applications 608 27.4.1 Separating a Mixture of Herbicides 609 27.4.2 Synthesis of a-Aspartame 609 27.4.3 Chiral Separation of Amino Acids by Ligand Exchange at a Metal Site 610 27.4.4 Specific Elimination of Lanthanides and Actinides in a Highly Radioactive Efiluent 610 27.5 Recent Challenges and Progress 612 References 613

Part V Applications of Nanomaterials

28 Electronics and Electromagnetism J.-C. Nece, D. Givord 617 28.1 Multilayer Ceramic Capacitors 617 28.1.1 What Is a Multilayer Ceramic Capacitor? 617 28.1.2 Market Requirements 619 28.1.3 Constraints Laid Down by these Requirements 620 28.1.4 BaTiO3 Ceramic Dielectrics with Nanograins: The Favoured Solution 621 28.2 Magnetic Recording 626 28.2.1 General Operation 626 28.2.2 Recording Materials. Longitudinal and Perpendicular Recording 627 28.2.3 Write Heads 629 28.2.4 Read Heads 629 28.2.5 Disk Drive Motor 630 References 631 29 Optics P. Maestro, M. Chagny, P.-P. Jobert, H. Van Damme, S. Berthier 633 29.1 Cosmetics 633 29.1.1 Introduction 633 29.1.2 Nano-Titanium Oxides in Cosmetics: Solar Skin Protection 633 29.1.3 Conclusion 635 29.2 Nanophosphors 635 29.2.1 Introduction 635 29.2.2 Phosphors: General Considerations 636 29.2.3 Operating Principle 638 XXII Contents 29.2.4 Industrial Applications 638 29.2.5 Conclusion 640 29.3 Surface Nanoengineering 640 29.3.1 What Is the Surface Area of a Town? 640 29.3.2 Superhydrophobic Surfaces 641 29.3.3 Self-Cleaning and Superhydrophilic Surfaces 644 29.3.4 When Concrete Cleans the Air We Breathe 648 29.4 Photonic Crystals 649 29.4.1 The Colourful World of Birds and Insects 649 29.4.2 Photonic Crystals and Photonic Band Gaps 650 29.4.3 Guides and Cavities 653 29.4.4 From Colloidal Crystals to Photonic Crystals 654 References 658

30 Mechanics P. Maestro, E. Gaffet, G. Le Ca6r, A. Mocellin, E. Reynaud, T. Rouxel, M. Soulard, J. Patarin, L. Thilly, F. Lecouturier 661 30.1 Silica Precipitates for High-Performance Tyres 661 30.1.1 Fabrication of Silica Precipitates 661 30.1.2 Tyres and Other Applications 662 30.2 Ceramic—Metal Composite Welding Supports 663 30.2.1 Ceramics 664 30.2.2 Reactive Mechanical Alloying and High-Energy Ball Milling 665 30.2.3 Improving Properties 667 30.3 Reinforced Amorphous Matrices 668 30.3.1 Not All Materials Are Ordered 668 30.3.2 Incorporating Nanoparticles into Amorphous Matrices .... 669 30.3.3 Prospects 673 30.3.4 The Long Road 675 30.4 Nanoporous Solids as Molecular Springs, Shock Absorbers and Bumpers 676 30.4.1 Introduction. 676 30.4.2 Basic Idea 676 30.4.3 Pressure—Volume Diagram 677 30.4.4 Stored Energy and Restored Energy 678 30.4.5 Causes of Irreversibility 679 30.4.6 Behaviour of the Solid and Liquid 680 30.4.7 Practical Applications 683 30.5 High Field Coils 685 30.5.1 Specifications for Generating High Pulsed Magnetic Fields . 685 30.5.2 Synthesis of Reinforced Copper Matrix Conductors 687 30.5.3 Geometry and Microstructure of Cu/Nb Nanofilamentary Conductors 688 Contents XXIII 30.5.4 Physical Properties of Cu/Nb Nanofilamentary Conductors 690 30.5.5 Conclusion 693 References 693

31 Biology and the Environment P. Maestro, P. Couvreur, D. Roux, D. Givord, J.-A. Dalmon, J.-C. Bertolini, F.J. Cadete Santos Aires 695 31.1 Inorganic Catalysts for Diesel Engines 695 31.2 Nanotechnology and New Medicines 697 31.2.1 Introduction 697 31.2.2 Artificial Carriers: Liposomes and Nanoparticles 697 31.2.3 Conclusion 701 31.3 Magnetic Nanoparticles and Biomedical Applications 701 31.3.1 Magnetotactic Bacteria 702 31.3.2 Homing Pigeons 702 31.3.3 Magnetic Separation 703 31.3.4 Magnetic Nanoparticles as MRI Contrast Agents 704 31.3.5 Magnetic Nanoparticles and Treatment of Tumours 705 31.4 Zeolitic Membranes for Separation Processes and Catalytic Reactors 706 31.4.1 Introduction 706 31.4.2 Microporous Membranes 707 31.4.3 Zeolitic Membranes: Synthesis and Characterisation 707 31.4.4 Application to Gas Separation 708 31.4.5 Application to a Catalytic Reactor 709 31.5 Metal Nanoparticles and Catalysis 710 31.5.1 Synthesis and Characterisation of Pd/Si3N4 Catalysts 711 31.5.2 Total Oxidation of Methane: Implementation in the Laboratory 713 31.5.3 Application to Radiant Panels (Infrared Energy Emission) 713 References 715

Index 717