Shi Nanomaterials and Devices

1. Auflage 2014
ISBN: 978-1-4557-7749-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 372 Seiten

Reihe: Micro and Nano Technologies

Introducing the fields of nanomaterials and devices, and their applications across a wide range of academic disciplines and industry sectors, Donglu Shi bridges knowledge acquisition and practical work, providing a starting point for the research and development of applications. The book describes characterization of nanomaterials, their preparation methods and performance testing techniques; the design and development of nano-scale devices; and the applications of nanomaterials, with examples taken from different industry sectors, such as lighting, energy, bioengineering and medicine / medical devices. Key nanomaterial types are covered, such as carbon nanotubes, nanobiomaterials, nano-magnetic materials, semiconductor materials and nanocomposites. Shi also provides detailed coverage of key emerging technologies such as DNA nanotechnology and spintronics. The resulting text is equally relevant for advanced students (senior and graduate) and for engineers and scientists from a variety of different academic backgrounds working in the multi-disciplinary field of nanotechnology. - Provides detailed guidance for the characterization of nanomaterials, their preparation, and performance testing - Explains the principles and challenges of the design and development of nano-scale devices - Explores applications through cases taken from a range of different sectors, including electronics, energy and medicine.

Autoren/Hrsg.

Shi, Donglu

Inhaltsverzeichnis

1;Front Cover;1
2;Nanomaterials and Devices;4
3;Copyright Page;5
4;Contents;6
5;Preface;10
6;1 Basic Properties of Nanomaterials;12
6.1;1.1 The Nanometer and Its Brief History, Nanoscience, and Nanotechnology;13
6.2;1.2 Characteristics of Nanomaterials;16
6.2.1;1.2.1 Perfect Law of Nanomaterials;16
6.2.2;1.2.2 Nano-Effect;17
6.2.2.1;1.2.2.1 Exceptional Optical Properties;18
6.2.2.2;1.2.2.2 Exceptional Thermal Properties;19
6.2.2.3;1.2.2.3 Exceptional Magnetic Properties;20
6.2.2.4;1.2.2.4 Exceptional Mechanical Properties;21
6.2.2.5;1.2.2.5 Exceptional Electrical Properties;21
6.2.3;1.2.3 Natural Nano-Effect;22
6.3;1.3 Physical Principles of the Nano-Effect;23
6.3.1;1.3.1 Discontinuity of Electron Levels;24
6.3.2;1.3.2 Kubo Theory;25
6.3.2.1;1.3.2.1 Hypothesis Regarding Degenerate Fermi Liquid;26
6.3.2.2;1.3.2.2 Electrically Neutral Assumption of Ultrafine Particles;26
6.3.3;1.3.3 Quantum Size Effect;27
6.3.4;1.3.4 Small Size Effect;29
6.3.5;1.3.5 Surface Effect;31
6.3.6;1.3.6 Dielectric Confinement Effect;32
6.4;References;34
7;2 Characterization and Analysis of Nanomaterials;36
7.1;2.1 Detection and Analysis of Particle Size;37
7.2;2.2 Detection and Analysis of the Electrical Properties;39
7.3;2.3 Detection and Analysis of Magnetic Properties;41
7.4;2.4 Detection and Analysis of the Mechanical Properties;43
7.5;2.5 Detection and Analysis of Thermal Properties;44
7.6;2.6 Detection and Analysis of Optical Properties;48
7.7;2.7 Scanning Probe Microscopy;49
7.7.1;2.7.1 Working Principles of Scanning Tunneling Microscopy;50
7.7.2;2.7.2 Operating Mode of STM;50
7.7.3;2.7.3 STM Application: Atomic Manipulation;52
7.7.4;2.7.4 Advantages of STM;54
7.8;2.8 Atomic Force Microscopy;54
7.8.1;2.8.1 Working Principle of AFM;54
7.8.2;2.8.2 Comparison of the AFM Scanning Modes;55
7.8.3;2.8.3 Application Examples of AFM;55
7.9;References;57
8;3 Carbon Nanotubes;60
8.1;3.1 Allotropes of Carbon and Structure;61
8.1.1;3.1.1 Allotropes of Carbon;61
8.1.2;3.1.2 Structures of Carbon Allotropes;61
8.1.3;3.1.3 Graphene;63
8.1.3.1;3.1.3.1 Single-Layer Graphite Material (Graphene);63
8.2;3.2 Types and Nature of CNTs;64
8.2.1;3.2.1 Types of CNTs;64
8.2.2;3.2.2 Characteristics of CNTs;65
8.2.2.1;3.2.2.1 Mechanical Properties;65
8.2.2.2;3.2.2.2 Electrical Characteristics;66
8.2.2.3;3.2.2.3 Thermal Properties;66
8.2.2.4;3.2.2.4 Superconducting Phenomenon of CNTs;67
8.2.2.5;3.2.2.5 Chemical Properties;67
8.2.3;3.2.3 Electronic Structure of CNTs;68
8.2.3.1;3.2.3.1 p-Electron Orbital and the Energy of the Conjugated Molecule in Planar Structure;68
8.2.3.2;3.2.3.2 Electronic Structure of Graphite;70
8.3;3.3 Preparation of CNTs;71
8.4;3.4 Applications of CNTs;73
8.4.1;3.4.1 CNT Electronics;73
8.4.1.1;3.4.1.1 The Limits of Microelectronics Technology and the Emergence of Nanoelectronics;73
8.4.1.2;3.4.1.2 Single-Electron Transistor;76
8.4.1.3;3.4.1.3 CNT Electronics;82
8.4.1.3.1;3.4.1.3.1 Quantum Wire;82
8.4.1.3.1.1;Conductivity of an SWNT;83
8.4.1.3.1.2;Conductivity of a Single MWNT;83
8.4.1.3.2;3.4.1.3.2 CNT-Based Junction;83
8.4.1.3.3;3.4.1.3.3 SET with CNTs;85
8.4.1.3.4;3.4.1.3.4 CNT-Based FET;86
8.4.1.3.5;3.4.1.3.5 Complementary Nongate (Inverter) Circuit with CNTs;87
8.4.2;3.4.2 Other Applications of CNTs;89
8.4.2.1;3.4.2.1 Nano Test Tubes;90
8.4.2.2;3.4.2.2 Nanobalance;90
8.4.2.3;3.4.2.3 Nanomolds;90
8.4.2.4;3.4.2.4 CNTs: Field Emission Cathode Materials;90
8.4.2.5;3.4.2.5 Application of CNTs in Hydrogen Storage;91
8.4.2.6;3.4.2.6 High-Energy Microbattery;92
8.4.2.7;3.4.2.7 High-Energy Capacitor;92
8.4.2.8;3.4.2.8 Chip Thermal/Heat Protection;92
8.4.2.9;3.4.2.9 Nanoreactor;92
8.4.2.10;3.4.2.10 Nanocomposite Materials;92
8.5;References;93
9;4 Semiconductor Quantum Dots;94
9.1;4.1 The Physical Basis of Semiconductor QDs;95
9.1.1;4.1.1 Quantum Confinement Effect;95
9.1.2;4.1.2 Excitons and Luminescence;98
9.1.2.1;4.1.2.1 The Concept of Excitons;98
9.1.2.2;4.1.2.2 Energy Band Structure of Excitons;99
9.1.3;4.1.3 Calculations of the Exciton Binding Energy;102
9.2;4.2 Preparation of Semiconductor QDs;104
9.3;4.3 Laser Devices Based on QDs;107
9.4;4.4 Single-Photon Source;111
9.5;References;115
10;5 Nanomagnetic Materials;116
10.1;5.1 Types of Nanomagnetic Materials;117
10.1.1;5.1.1 Artificial and Natural Nanomagnetic Materials;117
10.1.2;5.1.2 Classification of Magnetic Nanomaterials;119
10.2;5.2 Basic Characteristics of Nanomagnetic Materials;122
10.2.1;5.2.1 Magnetic Domain;123
10.2.2;5.2.2 Superparamagnetic Feature;125
10.2.3;5.2.3 Exchange Interaction;126
10.2.4;5.2.4 Coercivity Hc;128
10.2.5;5.2.5 Curie Temperature;128
10.2.6;5.2.6 Susceptibility;129
10.3;5.3 Some Specific Nanomagnetic Materials;130
10.3.1;5.3.1 Magnetic Fluids;130
10.3.2;5.3.2 Magnetic Microspheres;135
10.3.3;5.3.3 One-Dimensional Nanowires;135
10.3.4;5.3.4 Two-Dimensional Films;137
10.3.5;5.3.5 Magnetic Nanocomposite Materials;137
10.3.6;5.3.6 Double-Phase Nanocomposite Hard Magnets;140
10.3.7;5.3.7 High-Frequency Microwave Nanomagnetic Materials;140
10.4;5.4 Preparation of Nanomagnetic Materials;143
10.4.1;5.4.1 Classification;143
10.4.2;5.4.2 Specific Instances;144
10.4.2.1;5.4.2.1 Mechanical Crushing Method;144
10.4.2.2;5.4.2.2 Etching Method;146
10.4.2.3;5.4.2.3 Physical Method;146
10.4.2.4;5.4.2.4 Chemical Method;147
10.4.2.5;5.4.2.5 Preparation of Magnetic Nanoparticles in the Magnetic Fluid;149
10.4.2.6;5.4.2.6 Two-Dimensional Nanowire Array: Template Method;150
10.5;5.5 GMR Materials;153
10.5.1;5.5.1 GMR Effect and Applications;153
10.5.2;5.5.2 Classification and Comparison of Magnetic Resistance;155
10.5.3;5.5.3 Physical Mechanism of GMR;160
10.5.3.1;5.5.3.1 Magnetic Exchange Coupling;160
10.5.3.2;5.5.3.2 GMR Effects of Metal Superlattice;161
10.5.4;5.5.4 GMR Biosensors;163
10.5.4.1;5.5.4.1 Introduction of Biosensors;164
10.5.4.2;5.5.4.2 GMR Sensor Chip;165
10.5.4.3;5.5.4.3 GMR Biosensors;166
10.6;References;169
11;6 Nanotitanium Oxide as a Photocatalytic Material and its Application;172
11.1;6.1 Principle of TiO2 Photocatalysis;173
11.1.1;6.1.1 Development of Photocatalytic Technology;173
11.1.2;6.1.2 Principles of Semiconductor (TiO2) Photocatalysis;173
11.2;6.2 Preparation of TiO2 Materials;177
11.3;6.3 Application of TiO2 as Photocatalytic Material;180
11.4;References;184
12;7 Electro-Optical and Piezoelectric Applications of Zinc Oxide;186
12.1;7.1 Optoelectronic Applications;186
12.1.1;7.1.1 Optical Properties of Zinc Oxide;186
12.1.2;7.1.2 Epitaxial Growth of ZnO;190
12.1.2.1;7.1.2.1 MBE Technique with Microwave;190
12.1.2.2;7.1.2.2 L-MBE Growth Technique;190
12.1.3;7.1.3 Optical Properties of ZnO Quantum Dots;192
12.1.4;7.1.4 Controlled Synthesis of the Ordered ZnO Nanowire Arrays;194
12.1.4.1;7.1.4.1 VLS Growth;194
12.1.4.2;7.1.4.2 VS Growth;195
12.1.4.3;7.1.4.3 The Hydrothermal Method;195
12.2;7.2 Piezoelectric Applications of Zinc Oxide;196
12.2.1;7.2.1 Piezoelectric Effect;196
12.2.2;7.2.2 Piezoelectric Application of Zinc Oxide: Nanogenerators;198
12.2.2.1;7.2.2.1 Why Do We Need Nanogenerators?;198
12.2.2.2;7.2.2.2 Principle of Piezoelectric Nanogenerators;199
12.3;References;201
13;8 Superconducting Nanomaterials;202
13.1;8.1 Superconductivity;202
13.2;8.2 The Physical Principles of Superconductivity;204
13.3;8.3 The Classification of Superconductors;206
13.3.1;8.3.1 Low-Temperature Superconductors;206
13.3.2;8.3.2 High-Temperature Superconductors;206
13.3.3;8.3.3 Other Novel Superconductors;207
13.4;8.4 Nanosuperconductors;208
13.4.1;8.4.1 Research Progress;208
13.4.2;8.4.2 The Main Difficulties;212
13.4.2.1;8.4.2.1 Incredible Magnetic Nanoclusters;212
13.4.2.2;8.4.2.2 Quantum Fluctuations and Strong Correlation in Nanowires;213
13.4.2.3;8.4.2.3 Ultrathin Film;213
13.4.2.4;8.4.2.4 Proximity Effect;214
13.4.2.5;8.4.2.5 Nanosuperconductors and Hybrid Structures;214
13.4.2.6;8.4.2.6 Links Between Superconductors and Nanostructure;215
13.5;8.5 Application of Nanosuperconductors;215
13.5.1;8.5.1 Quantum Computers;216
13.5.2;8.5.2 Nanosuperconductor Quantum Bits;218
13.6;References;223
14;9 Nanobiological Materials;226
14.1;9.1 Nanobiological Materials;228
14.1.1;9.1.1 Overview;228
14.1.2;9.1.2 Drug and Gene Carrier Nanomaterials;229
14.1.2.1;9.1.2.1 Nanolilmsome;230
14.1.2.2;9.1.2.2 Solid Lipid Nanoparticles;231
14.1.2.3;9.1.2.3 Nanocapsules and Nanospheres;231
14.1.2.4;9.1.2.4 Polymer micelles;231
14.1.3;9.1.3 Bioceramic Nanomaterials;232
14.1.4;9.1.4 Magnetic Nanoparticles;233
14.1.5;9.1.5 Biocomposite Nanomaterials;234
14.2;9.2 Nanobiomedical Materials;235
14.2.1;9.2.1 Nanobioinorganic Materials;236
14.2.2;9.2.2 Nanoorganic Biological Material;237
14.2.2.1;9.2.2.1 Nanopolymeric Biological Materials;237
14.2.2.2;9.2.2.2 Nanobiocomposite Materials;238
14.2.3;9.2.3 Nanotechnology in Drugs;238
14.2.4;9.2.4 Biochips;239
14.2.5;9.2.5 Future Development of Nanobiomedical Materials;240
14.2.5.1;9.2.5.1 Nanorobots;240
14.2.5.2;9.2.5.2 Targeted Nanomedicine;241
14.2.5.3;9.2.5.3 Capabilities and Intelligence of Invasive Diagnosis;241
14.2.5.4;9.2.5.4 Drug Delivery Systems;241
14.2.5.5;9.2.5.5 Medical Composite Materials;242
14.3;9.3 Magnetic Particles in Medical Applications;242
14.4;9.4 Nanoparticles in Bioanalysis;245
14.5;9.5 QDs in Biological and Medical Analysis;249
14.5.1;9.5.1 QDs in Biological and Medical Analysis;250
14.5.2;9.5.2 QDs for In Vivo Studies;255
14.6;9.6 Research Progress of Nanomagnetic Materials in Hyperthermia;256
14.6.1;9.6.1 Background of Hyperthermia;256
14.6.2;9.6.2 Magnetic Hyperthermia;259
14.6.3;9.6.3 Magnetic Materials for Hyperthermia;261
14.6.4;9.6.4 Thermogenesis Mechanism of Magnetic Materials for Magnetic Hyperthermia;261
14.7;References;264
15;10 Nanoenergy Materials;266
15.1;10.1 Nanostorage Materials;269
15.1.1;10.1.1 Features and Objectives of Hydrogen Energy;270
15.1.2;10.1.2 Comparison of Different Hydrogen Storage Methods;270
15.1.3;10.1.3 Technology Status of Hydrogen Storage Materials;270
15.2;10.2 Fuel Cells;275
15.2.1;10.2.1 Basic Concept;275
15.2.2;10.2.2 Comparison of the Main Fuel Cells;278
15.2.3;10.2.3 Proton-Exchange Membrane;280
15.2.4;10.2.4 Nanofuel Cells;283
15.3;10.3 Dye-Sensitized Nanocrystalline Solar Cells;284
15.3.1;10.3.1 Status of Solar Cells;284
15.3.2;10.3.2 Types of Solar Cell;285
15.3.2.1;10.3.2.1 Inorganic Solar Cells;285
15.3.2.1.1;10.3.2.1.1 Silicon Wafer Solar Cells;286
15.3.2.1.2;10.3.2.1.2 Amorphous Silicon Solar Cells;287
15.3.2.1.3;10.3.2.1.3 Copper Indium Gallium Diselenide Solar Cells;288
15.3.2.1.4;10.3.2.1.4 Cadmium Telluride Thin-Film Solar Cells;289
15.3.2.1.5;10.3.2.1.5 Silicon Thin-Film Solar Cells;290
15.3.2.2;10.3.2.2 Organic Solar Cells;291
15.3.3;10.3.3 Dye-Sensitized Nanocrystalline Solar Cells;292
15.3.3.1;10.3.3.1 The History of Dye-Sensitized Nanocrystalline Solar Cells;292
15.3.3.2;10.3.3.2 Cell Structure;293
15.3.3.3;10.3.3.3 Working Principle;293
15.3.3.4;10.3.3.4 Parameters for Performance Evaluation;295
15.3.3.5;10.3.3.5 Research Progress;296
15.3.3.5.1;10.3.3.5.1 Sensitizer;296
15.3.3.5.2;10.3.3.5.2 Nanosemiconductor materials;297
15.3.3.5.3;10.3.3.5.3 Electrolyte;299
15.3.3.6;10.3.3.6 Main Problems;299
15.3.3.7;10.3.3.7 Flexible DSSC Cells;301
15.4;References;301
16;11 Nanocomposites;304
16.1;11.1 Concept and History;305
16.2;11.2 Surface Modification of Nanomaterials and Their Applications;306
16.2.1;11.2.1 Nanosurface Engineering;307
16.2.2;11.2.2 Mechanism of Surface Modification of Nanoparticles;308
16.2.2.1;11.2.2.1 Coating Modification;309
16.2.2.2;11.2.2.2 Coupling Modification;309
16.2.3;11.2.3 Surface Modifiers of Nanoparticles;310
16.2.3.1;11.2.3.1 Inorganic Compounds for the Surface Modification of Nanoparticles;310
16.2.3.2;11.2.3.2 Surface Modification with Nanoparticles;310
16.2.3.3;11.2.3.3 Surface Modification with Organic Compounds;311
16.2.3.4;11.2.3.4 Surface Modification with Polymers;312
16.2.4;11.2.4 Implementation of Nanoparticle Modification;312
16.2.5;11.2.5 Application of Modified Nanoparticles;314
16.2.5.1;11.2.5.1 Application in Plastics;314
16.2.5.2;11.2.5.2 Application in Composite Fire-Retardant Materials;314
16.2.5.3;11.2.5.3 Application in Composite Catalysts;314
16.2.5.4;11.2.5.4 Application in the Field of Lubrication;315
16.2.5.5;11.2.5.5 Applications in Composite Coating;315
16.2.5.6;11.2.5.6 Application in Rubber;315
16.3;11.3 Core–Shell Structure Composite Nanomaterials;316
16.3.1;11.3.1 Characteristics of Core–Shell Composite Structures;316
16.3.2;11.3.2 Composite Method;317
16.3.2.1;11.3.2.1 Polymerization Chemical Reaction;317
16.3.2.2;11.3.2.2 Biological Macromolecular Method;318
16.3.2.3;11.3.2.3 Surface Deposition and Surface Chemical Reaction Method;318
16.3.2.4;11.3.2.4 Controlled Deposition of Inorganic Colloidal Particles on the Core Particle Surface;319
16.3.2.5;11.3.2.5 Ultrasonic Chemical Method;320
16.3.2.6;11.3.2.6 Self-assembly;320
16.3.3;11.3.3 Mechanism of Formation of Core–Shell Structures;321
16.3.3.1;11.3.3.1 Mechanism of Chemical Bonding;321
16.3.3.2;11.3.3.2 Mechanism of Coulomb Electrostatic Force;321
16.3.3.3;11.3.3.3 Mechanism of Adsorption Layer Media;321
16.3.4;11.3.4 Changes in Material Properties;322
16.3.4.1;11.3.4.1 Changes in Optical Properties;322
16.3.4.2;11.3.4.2 Increase in the Stability of Particles;322
16.3.4.3;11.3.4.3 Catalyst Stability and Changes in Catalytic Activity;323
16.3.4.4;11.3.4.4 Changes in Magnetic;323
16.3.5;11.3.5 Applications of Core–Shell Composite Nanomaterials;324
16.4;References;326
17;12 DNA Nanotechnology;328
17.1;12.1 Basics of DNA;328
17.1.1;12.1.1 Unique Structure of DNA;328
17.1.2;12.1.2 DNA Conductivity;329
17.1.3;12.1.3 Simplest Equivalent Model of DNA Conduction;333
17.1.4;12.1.4 Advantages of DNA Molecular Devices;335
17.2;12.2 DNA Nanotechnology;336
17.2.1;12.2.1 DNA for the Assembly of Nanoparticles;336
17.2.2;12.2.2 Driving Force for Self-Assembly of DNA Templates;337
17.2.3;12.2.3 DNA as a Template to Prepare Molecular Wire;339
17.3;12.3 DNA Molecular Motors;340
17.3.1;12.3.1 Drexler Conjecture;340
17.3.2;12.3.2 Molecular Motors;342
17.3.3;12.3.3 Basic Principle of Molecular Motors;343
17.3.4;12.3.4 DNA Molecular Motors;346
17.3.4.1;12.3.4.1 DNA Applications in Molecular Devices;346
17.3.4.2;12.3.4.2 DNA Molecular Motors;346
17.4;References;348
18;Index;350

Leseproben

2 Characterization and Analysis of Nanomaterials
In order to elucidate nanoscale-driven properties, thorough characterization and analysis is required as materials with identical chemical composition can have vastly different properties depending on the size-scale of the material. As such, Chapter 2 is devoted to summarizing many aspects of nanoscale materials characterization and property analysis. Structural and chemical methods will be introduced, along with various microscopy methods. Methods for determining electrical, magnetic, mechanical, thermal, and optical properties will be summarized. Keywords
Size analysis; structure analysis; nanoscale properties; electron microscopy; atomic force microscopy Chapter Outline 2.1 Detection and Analysis of Particle Size 26 2.2 Detection and Analysis of the Electrical Properties 28 2.3 Detection and Analysis of Magnetic Properties 30 2.4 Detection and Analysis of the Mechanical Properties 32 2.5 Detection and Analysis of Thermal Properties 33 2.6 Detection and Analysis of Optical Properties 37 2.7 Scanning Probe Microscopy  38 2.7.1 Working Principles of Scanning Tunneling Microscopy 39 2.7.2 Operating Mode of STM 39 2.7.3 STM Application: Atomic Manipulation 41 2.7.4 Advantages of STM 43 2.8 Atomic Force Microscopy 43 2.8.1 Working Principle of AFM 43 2.8.2 Comparison of the AFM Scanning Modes 44 2.8.3 Application Examples of AFM 44 References 46 Complete characterization and analysis of nanomaterials include particle composition, particle size distributions, morphology/shape, structural analysis, surface characterization, surface area analysis, optical properties, magnetic properties, and others [1]. Conventional characterization methods for nanomaterials can vary from system to system but commonly include transmission electron microscopy (TEM), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS), inductively coupled plasma mass spectroscopy (ICP-MS), vibrating sample magnetometer (VSM), Auger electron spectroscopy (AES), Mossbauer spectroscopy, and differential scanning calorimetry (DSC), to name a few. For nanoparticles with a size less than 10 nm, different techniques are required, such as high-resolution electron microscopy (HRTEM), Raman spectroscopy, nuclear magnetic resonance (NMR), ultraviolet photoemission spectroscopy (UPS), scanning tunneling electron microscopy (STEM), secondary ion mass spectroscopy, second neutral-atom mass spectroscopy (SNMS), and field-emission scanning transmission electron microscopy (FE-STEM). Table 2.1 highlights characterization techniques used for nanomaterials with the type of information obtained and the resolution of the instruments (TFXRD indicates thin-film XRD and TC indicates texture cradle). Table 2.1 Comparison of the Performance of Different Testing and Analytical Instruments for Nanomaterials Surface analysis AES Surface composition, chemical bonding 1 µm AFM Surface structure 5 nm XPS Surface composition, chemical bonding 5 nm SIMS Surface composition, in-depth analysis 50 µm Electron microscopy SEM (×2) Surface microstructure, composition analysis, material analysis 0.1 µm TEM/STEM Internal microstructure, crystal structure, composition analysis 0.4/20 nm HREM Crystal (atomic/molecular) structure, interface structure 0.18 nm XRD XRD Crystal structure, phase identification   TFXRD Phase identification of films, film thickness   TC Hole image   2.1 Detection and Analysis of Particle Size
First, we need to find a way to define the size of nanomaterials. For spherical nanoparticles, the diameter is defined as the size of the nanoparticle. As for nanomaterials of asymmetric shapes, the following four definitions are usually used: geometric diameter, equivalent diameter, SSA (specific surface area) diameter, and refraction diameter. Geometric diameter: For particles of any geometric shape, the largest projected area can be converted into a circle of the same size. The diameter of this circle is the geometric diameter of particles. Equivalent diameter: The size of powder particles can be measured by using the sedimentation method, centrifugal method, mechanical method, or hydraulic method. Homogeneous spherical particles, for example, have the same terminal settling velocity as nanoparticles; their diameter shall have an equivalent diameter of the nanoparticles. SSA diameter: Using a variety of possible techniques, the SSA of the nanoparticle can be determined. From the surface area, a diameter can be calculated by one of the even spherical particles with the same formula: s=6[??m]VS
Here, ds is the SSA particle size, is the sample density, V is volume of material tested, m is the density of the bulk materials, and S is the calculated surface area of the particles. Refraction diameter: The diameter of the nanoparticle as determined using XRD techniques.
Typically, the calculated diameter will vary depending on the method used, as shown in Table 2.2.
SSA diameter can be measured by using chemical and physical adsorption methods. Physical adsorption and chemical adsorption are compared in Table 2.3. Table 2.2 Determination of Particle Size Geometric diameter Optical microscopy 500–0.2 Number distribution Electron microscopy 10–0.01 Number distribution Equivalent diameter Gravity sedimentation 50–1 Mass distribution Centrifugal sedimentation 10–0.01 Mass distribution Gas precipitation 50–1 Mass distribution Proliferation 0.5–0.001 Mass distribution SSA size Adsorption (gas) 20–0.001 Average SSA size Infiltration (gas) 50–0.2 Average SSA size Wetting heat 12–0.001 Average SSA size Refraction diameter Refraction 12–0.001 Volume distribution X-ray line width 0.05–0.0001 Volume distribution X-ray scattering at small-angle 0.1–0.001 Volume distribution Table 2.3 Comparison of Physical Adsorption and Chemical Adsorption Adsorbability van der Waals force Atomic bonding force Heat of adsorption 10 kcal/more 10–100 kcal/more Optionality None (applicable to any system at low temperatures) Selectivity Absorption rate Quickly (unable to be determined) Usually not too fast (able to be determined) Adsorption layer Adsorption on multi-molecular layer Adsorption on single-molecule layer Fixed temperature adsorption Decreased at high temperatures (decreasing with temperature increase) Increased at high temperature (increasing with temperature increase) Reversibility Easy to fall off Not easy to fall off The BET (Brunauer, Emmett, and Teller) method using multilayer gas adsorption is commonly used for the measurement of SSA materials in the solid phase. It is generally performed using two methods: the volumetric and the gravimetric methods. The volumetric method uses differences in sample volume of a known quantity of gas before and after...