A complete nanoparticle resource for chemists and industry professionals
Metal oxide nanoparticles are integral to a wide range of natural and technological processes - from mineral transformation to electronics. Additionally, the fields of engineering, electronics, energy technology, and electronics all utilize metal oxide nanoparticle powders. Metal Oxide Nanoparticles: Formation, Functional Properties, and Interfaces presents readers with the most relevant synthesis and formulation approaches for using metal oxide nanoparticles as functional materials. It covers common processing routes and the assessment of physical and chemical particle properties through comprehensive and complementary characterization methods.
This book will serve as an introduction to nanoparticle formulation, their interface chemistry and functional properties at the nanoscale. It will also act as an in-depth resource, sharing detailed information on advanced approaches to the physical, chemical, surface, and interface characterization of metal oxide nanoparticle powders and dispersions.- Addresses the application of metal oxide nanoparticles and its economic impact- Examines particle synthesis, including the principles of selected bottom-up strategies- Explores nanoparticle formulation - a selection of processing and application routes- Discusses the significance of particle surfaces and interfaces on structure formation, stability and functional materials properties- Covers metal oxide nanoparticle characterization at different length scales
With this valuable resource, academic researchers, industrial chemists, and PhD students can all gain insight into the synthesis, properties, and applications of metal oxide nanoparticles.
Table of Contents
List of contributors
Preface
Part I Introduction
1 Metal Oxides and Specific Functional Properties at the Nanoscale
Oliver Diwald
1.1 A Cross-Sectional Topic in Materials Science and Technology
1.2 Metal Oxides: Bonding and Characteristic Features
1.3 Regimes of Size-Dependent Property Changes and Confinement Effects
1.4 Distribution of Nanoparticle Properties
1.5 Structure and Morphology
1.5.1 Confinement and Structural Disorder
1.5.2 Surface Free Energy Contributions and Metastability
1.5.3 Shape
1.6 Electronic Structure and Defects
1.6.1 Size-Dependent Defect Formation Energies and Their Impact on Surface Reactivity
1.7 Surface Chemistry
1.8 Metal Oxide Nanoparticle Ensembles as Dynamic Systems
1.9 Organization of This Book
2 Application of Metal Oxide Nanoparticles and their Economic Impact
Karl-Heinz Haas
2.1 Introduction
2.1.1 Nanomaterials and Nanoobjects
2.1.2 Selection of Metal Oxide Nanoparticles
2.2 Scientific and Patent Landscape
2.3 Types of Metal Oxide Nanoparticles, Properties, and Application Overview
2.4 Use Forms of Metal Oxide Nanoparticles and Related Processing
2.4.1 Metal Oxide Nanoparticle Powders for Ceramics
2.4.2 Metal Oxide Nanoparticle Dispersions
2.4.3 Composites
2.4.3.1 Polymer Based (Bulk and Coatings)
2.4.3.2 Metal Reinforcement
2.4.4 Combination with Powders of Micrometer Sized particles
2.5 Application Fields of Metal Oxide Nanoparticles
2.5.1 Agriculture
2.5.2 Sensors and Analytics
2.5.3 Automotive
2.5.4 Biomedical/Dental
2.5.4.1 Therapy
2.5.5 Catalysis
2.5.6 Consumer Products: Cosmetics, Food, Textiles
2.5.7 Construction
2.5.8 Electronics Including Magnetics
2.5.9 Energy
2.5.10 Environment, Resource Efficiency, Processing
2.5.11 Oil Field Chemicals and Petroleum Industries
2.5.12 Optics/Optoelectronics and Photonics
2.6 Economic Impact
2.7 Conclusion and Outlook
Part II Particle Synthesis: Principles of Selected Bottom-up Strategies
3 Nanoparticle Synthesis in the Gas Phase
Matthias Niedermaier, Thomas Schwab, and Oliver Diwald
3.1.Introduction
3.2.Some Key Issues of Particle Formation in the Gas Phase and in Liquids
3.3.Gas Phase Chemistry, Particle Dynamics, and Agglomeration
3.4.Gas-to-Particle Conversion
3.4.1.Physical Processes
3.4.2.Chemical Processes
3.5.Particle-to-Particle Conversion
3.5.1 Approaches and Precursors
3.5.2.Particle Formation
3.5.3.Experimental Realization
3.5.4.Spray Pyrolysis and Flame-Assisted Spray Pyrolysis
3.6.Gas Phase Functionalization Approaches
4 Liquid-Phase Synthesis of Metal Oxide Nanoparticles
Andrea Feinle and Nicola Hüsing
4.1 Introduction
4.2 General Aspects
4.2.1 Liquid-Phase Chemistry
4.2.2 Nucleation, Growth, and Crystallization
4.3 Synthetic Procedures
4.3.1 (Co)Precipitation
4.3.2 Sol-Gel Processing
4.3.3 Polyol-Mediated Synthesis/Pechini Method
4.3.4 Hot-Injection Method
4.3.5 Hydrothermal/Solvothermal Processing
4.3.6 Microwave-Assisted Synthesis
4.3.7 Sonication-Assisted Synthesis
4.3.8 Synthesis in Confined Spaces
4.4 Summary
5 Controlled Impurity Admixture: From Doped Systems to Composites
Alessandro Lauria and Markus Niederberger
5.1 Introduction
5.2 Liquid-Phase Synthesis of Doped Metal Oxide Nanoparticles
5.3 Gas-Phase Synthesis of Doped Metal Oxide Nanoparticles
5.4 Solid-State Synthesis of Doped Metal Oxide Nanoparticles
5.5 Phase Segregation: Formation of Heterostructures
5.6 Core/Shell and Heteromultimers
5.7 Summary and Conclusions
Part III Nanoparticle Formulation: A Selection of Processing and Application Routes
6 Colloidal Processing
Thomas Berger
6.1 Towards Complex Shaped and Compositionally Well-Defined Ceramics: The Need for Colloidal Processing
6.2 Colloidal Processing Fundamentals
6.2.1 Interparticle Forces
6.2.1.1 Electric Double Layer Forces
6.2.1.2 Polymer-Induced Forces
6.2.2 Forming and Consolidation Techniques
6.2.2.1 Drained Casting Techniques
6.2.2.2 Tape-Casting Techniques
6.2.2.3 Constant Volume Techniques
6.2.2.4 Drying and Cracking
6.3 Rheology of Suspensions
6.4 Electrostatic Heteroaggregation of Metal Oxide Nanoparticles
6.4.1 Modification of Colloidal Stability by Heteroaggregation
6.4.2 Structure Evolution upon Heteroaggregation in Binary Nanoparticle Dispersions
6.4.3 Rheological Properties of Binary Heterocolloids
6.4.4 Functional Properties of Heteroaggregates
6.5 Ice-Templating-Enabled Porous Ceramic Structures: A Case Example of the Impact of Nanoparticles on Colloidal Processes and Material Properties
6.5.1 Ice-Templating of Colloidal Particles
6.5.2 Capabilities of Metal Oxide Nanoparticles in Ice-Templating
6.5.2.1 Optimization of the Mechanical Properties of Green Bodies and Sintered Parts
6.5.2.2 Hierarchical Porosity and High Surface Area Materials
6.5.2.3 Triple Phase Boundaries Between Entangled Percolating Networks Consisting of Two Inorganic Phases and a Hierarchical Pore System
6.6 From Colloidal Processing to Nanoparticle Assembly: Towards the Control of Particle Arrangement Over Several Length Scales
7 Fabrication of Metal Oxide Nanostructures by Materials Printing
Petr Dzik, Michal Veselý, and Oliver Diwald
7.1 Introduction
7.2 Traditional Coating and Printing Techniques
7.3 Inkjet Printing
7.3.1 A Brief Introduction into IJP Technology and the Process Scheme
7.3.2 Functional Ink Formulation Issues
7.3.3 Drop Generation
7.3.4 Drop Interaction with the Substrate
7.3.5 Drop Drying and Pattern Formation
7.3.6 Printing Quality
7.3.7 Equipment and Printing Devices
7.4 Printing of Metal Oxide Structures: The Materials Aspect
7.4.1 Insulating Metal Oxides
7.4.2 Semiconducting Metal Oxides
7.4.3 Conducting Metal Oxides
7.5 Examples for Complex Printed Functional Structures: The Device Aspect
7.5.1 Printed Photoelectrochemical Cell
7.5.2 Flexible pH Sensors by Large Scale Layer-by-layer Inkjet Printing
7.6 Conclusions and Outlook
8 Nanoscale Sintering
Kathy Lu and Kaijie Ning
8.1 Background
8.2 Challenges and New Aspects of Nanoparticle Material Sintering
8.3 Questionable Nature of Existing Sintering Theories
8.4 3D Reconstruction
8.4.1 Focused Ion Beam Cross-Sectioning and SEM Imaging
8.4.2 X-ray Microtomography
8.5 Functions of Pores
8.6 Sintering of Small Features
8.6.1 New Sintering Questions
8.6.2 Role of Pore Number in Small Feature Sintering
8.6.3 Grain Boundary Diffusion vs. Grain Boundary Migration in Small Feature Sintering
8.6.4 Ceramic Type Effect on Small Feature Sintering
8.6.5 Atmosphere Effect on Small Feature Sintering
8.7 Summary
Part IV Metal Oxide Nanoparticle Characterization at Different Length Scales
9 Structure: Scattering Techniques
Günther J. Redhammer
9.1 Introduction
9.1.1 Scattering and Diffraction
9.1.2 What to Learn from a Diffraction Experiment?
9.2 Theoretical Background
9.2.1 Crystal Lattice, Planes, and Bragg’s Law
9.2.1.1 Crystal Planes and Interplanar Distance
9.2.1.2 The Reciprocal Lattice
9.2.1.3 Bragg’s Law
9.2.2 The Intensity of a Bragg Peak
9.2.3 The Profile of a Bragg Peak
9.2.3.1 Instrumental Broadening
9.2.3.2 Sample Broadening
9.2.3.3 Analytical Description of Peak Shapes
9.3 Experimental Setup
9.3.1 Single vs. Polycrystalline Samples
9.3.2 Powder Diffraction Methods
9.3.2.1 Reflection Geometry
9.3.2.2 Transmission Geometry
9.3.2.3 Grazing Incident Diffraction (GID)
9.3.2.4 Sample Preparation
9.4 Some Selected Applications
9.4.1 Qualitative Phase Analysis
9.4.2 Quantitative Phase Analysis - The Rietveld Method
9.4.3 Microstructure Analysis: Size and Strain
9.5 X-ray Diffraction on Magnetite Nanoparticles
9.6 Conclusion
10 Morphology, Structure, and Chemical Composition: Transmission Electron Microscopy and Elemental Analysis
Joanna Gryboś, Paulina Indyka, and Zbigniew Sojka
10.1 Size, Shape, and Composition of Oxide Nanoparticles
10.2 Interaction of the Incident Electrons with a Specimen
10.3 The Transmission Electron Microscope
10.3.1 Microscope Design and Operation Modes
10.3.2 Contrast Type and Image Formation
10.3.3 Resolution Limits of TEM Images
10.4 Imaging and Analysis of Morphology
10.4.1 Sample Preparation
10.4.2 Shape Retrieving
10.4.2.1 Aligned Nanocrystals
10.4.2.2 Randomly Oriented Nanocrystals
10.4.3 Particle Size Determination
10.5 Crystallographic Phase Identification - Electron Diffraction
10.5.1 Bragg Condition - Kinematical and Dynamical Diffraction
10.5.2 Selected Area Electron Diffraction (SAED)
10.5.3 Nanodiffraction
10.6 Chemical Composition Mapping - EDX and EELS Nanospectroscopy
10.6.1 Correlating Image with Spectroscopic EDX and EELS Information - Data Cubes
10.6.2 Composition Mapping with EDX Spectroscopy
10.6.3 Chemical State Imaging with EELS Spectroscopy
11 Electronic and Chemical Properties: X-ray Absorption and Photoemission
Paolo Dolcet and Silvia Gross
11.1 Introduction and Scope of the Chapter
11.2 Basics of X-rays - Matter Interaction
11.3 X-ray Photoelectron Spectroscopy (XPS)
11.3.1 Theoretical Background
11.3.2 Features and Analysis of X-ray Photoelectron Spectra
11.3.3 XPS Investigation of Metal Oxide Nanoparticles and Metal Oxide Colloidal Suspensions
11.3.3.1 Solid-Liquid Interfaces and Nanoparticles in Suspension: Liquid-Jet and Ambient Pressure XPS
11.3.3.2 Valence Band XPS for the Investigation of Oxides
11.3.4 XPS Spectrometer Equipment: Components and Sources
11.3.5 Performing XPS Experiments
11.3.5.1 Planning of the Analysis and Sample Preparation
11.3.6 XPS Qualitative and Quantitative Data Analysis and Fitting
11.4 X-ray Absorption Spectroscopy (XAS)
11.4.1 X-ray Absorption Theory
11.4.2 XAS for the Investigation of Metal Oxide Nanoparticles
11.4.2.1 Materials for Oxygen Evolution Reaction
11.4.2.2 Point Defects and Ferromagnetism
11.4.3 Anatomy of a XAS Beamline
11.4.4 The XAS Experiment: Obtaining Beamtime, Sample Preparation
11.5 Case Studies for the Combined Use of XPS and XAS in Oxide Analysis
11.6 Concluding Remarks: Complementarities and Differences of XPS and XAS
12 Optical Properties: UV/Vis Diffuse Reflectance Spectroscopy and Photoluminescence
Thomas Berger and Anette Trunschke
12.1 Interaction of Metal Oxide Particle-Based Materials with Light
12.2 Spectroscopic Techniques
12.2.1 Transmission Spectroscopy
12.2.2 Diffuse Reflectance Spectroscopy
12.2.2.1 Kubelka-Munk Theory
12.2.2.2 Measurement of Absorption Spectra in Diffuse Reflectance
12.2.2.3 Experimental Constraints and Sources of Error
12.2.2.4 Optical Accessories
12.2.3 Photoluminescence Spectroscopy
12.2.3.1 Principles of Photoluminescence Spectroscopy
12.2.3.2 Inorganic Luminescent Particles
12.2.4 In Situ Cells and Measurement Configurations
12.3 Types of Transitions
12.3.1 UV Region (5.0-2.5 eV)
12.3.1.1 Charge Transfer (CT) Transitions
12.3.1.2 Band-to-Band Transitions
12.3.1.3 Excitonic Surface States in Highly Dispersed Insulating Metal Oxides
12.3.1.4 Organic Ligands and Adsorbates
12.3.2 Visible Region (3.5-1.5 eV)
12.3.2.1 Metal Centered Transitions
12.3.2.2 Localized Surface Plasmon Resonance
12.3.3 Near-Infrared Region (1.5-0.5 nm)
12.3.3.1 Intraband Transitions: Free Carrier Absorption
12.3.3.2 Vibrational Transitions
12.3.3.3 Localized Surface Plasmon Resonance in Degenerately Doped Metal Oxide Semiconductor Nanocrystals
12.4 Case Studies
12.4.1 Heterogeneous Catalysis
12.4.2 Adsorption and Reaction of Porphyrins on Highly Dispersed MgO Nanocube Powders
13 Vibrational Spectroscopies
Christian Hess
13.1 Introduction
13.2 Basic Principles of Vibrational Spectroscopies
13.2.1 IR Spectroscopy
13.2.2 Raman Spectroscopy
13.2.3 Inelastic Neutron Scattering (INS)
13.2.4 In Situ/Operando Characterization
13.3 Vibrational Properties of Metal Oxide Nanoparticles
13.3.1 Structural Identification and Phase Transitions
13.3.2 Particle Size
13.3.3 Strain and Defects
13.3.4 Surface Hydroxyl Groups
13.3.5 Surface Oxygen Species
13.4 Case Study: Ceria Nanoparticles
13.5 Characterization of Metal Oxide Nanoparticles Under Working Conditions
13.6 Conclusions
14 Solid State Magnetic Resonance Spectroscopy of Metal Oxide Nanoparticles
Yamini S. Avadhut and Martin Hartmann
14.1 Introduction
14.2 Basics of Solid-state NMR Spectroscopy
14.2.1 Magic Angle Spinning
14.2.2 Cross-Polarization
14.2.3 Multiple Quantum Magic Angle Spinning
14.3 Selected Examples
14.4 Basics of Electron Paramagnetic Resonance Spectroscopy
14.4.1 The Spin Hamiltonian of Paramagnetic Systems
14.4.2 Defects
14.4.3 Transition Metal Ions
14.5 Selected Example
15 Characterization of Surfaces and Interfaces
Thomas Berger and Oliver Diwald
15.1 Interfaces Determine Stability and Functional Properties: From Manufactured Metal Oxide Nanoparticles to Surface Science Studies
15.2 From Crystal Faces to Nanocrystals: Surface Energetics and Wulff Constructions
15.2.1 Surface Tension, Surface Stress, and Surface Energy
15.2.2 Wulff Construction: A Starting Point for Modelling
15.2.3 Free Energies of Particle Formation and Particle Surfaces
15.3 Changing Interfaces and Microstructures
15.4 The Solid-Vacuum Interface
15.5 Solid-Vapor Interfaces: Thin Water Films as Reactive Environments
15.6 Solid-Liquid Interfaces
15.7 Solid-Solid Interfaces
15.8 Experimental Approaches for Surface and Interface Characterization
15.8.1 Gas Adsorption
15.8.2 He Pycnometry
15.8.3 Nonlinear Optics and Surface Specific Optical Probes
15.8.4 Atomic Force Microscopy (AFM)
15.8.5 Zeta Potential, Ambient Pressure X-ray Photoelectron Spectroscopy (AP-XPS), and Electrochemistry
15.8.6 Surface and Interface Energies
16 Adsorption and Chemical Reactivity
Oliver Diwald and Martin Hartmann
16.1 Introduction
16.2 Some Principles and Key Issues of Adsorption
16.2.1 Physisorption, Chemisorption, and Potential Energy Diagrams
16.2.2 Sticking Probability, Surface Residence Time, and Adsorption Isotherms
16.3 Adsorption in Metal Oxide Nanoparticle Ensembles
16.3.1 Microstructure and Porosity
16.3.2 Adsorption and Diffusion
16.4 Thermal Techniques to Characterize Sorption
16.4.1 Thermogravimetric Analysis (TGA)
16.4.2 Differential Thermal Analysis (DTA)
16.4.3 Differential Scanning Calorimetry (DSC)
16.4.4 Calorimetry
16.5 Temperature-Programmed Techniques
16.5.1 Temperature-Programmed Desorption (TPD)
16.5.2 Temperature-Programmed Reduction (TPR) and Oxidation (TPO)
16.5.3 Temperature-Programmed Surface Reaction (TPSR)
16.6 Adsorption in Liquids - Nanoparticle Dispersions
16.6.1 General Aspects of Adsorption in Solution
16.6.2 Adsorption and Exchange of Ligands at the Colloidal Interface
16.6.3 Grafting of Metal Oxide Nanoparticles with Surfactants
16.7 Nature and Abundance of Catalytically Active Centers
16.8 Probes to Characterize Strength and Activity of Catalytic Sites
16.9 Catalytic Test Reactions
16.9.1 Acidic and Basic Catalysts
16.9.2 Redox Reactions
16.9.3 Bifunctional Catalysis
16.10 Stability and Aging of Metal Oxide Nanoparticles in Catalysis
17 Particle Characterization Technology
Alfred P. Weber
17.1 Introduction
17.2 Sampling and Sample Preparation
17.2.1 Sampling
17.2.2 Sampling from the Gas Phase
17.2.3 Sampling from a Suspension and Sample Preparation
17.3 Image Analysis Techniques
17.3.1 Point operations
17.3.2 Linear Filter
17.3.3 Nonlinear Filter
17.3.4 Morphological Filtering
17.4 Counting Techniques for Single Suspended Nanoparticles
17.4.1 Wide Angle Laser Light Collector
17.4.2 Nano-Laser Doppler Anemometry (NanoLDA)
17.4.3 Condensation Particle Counter (CPC)
17.4.4 Nanoparticle Tracking Analysis (NTA)
17.4.5 Comparison of NTA and Dynamic Light Scattering (DLS)
17.5 Separation Techniques
17.5.1 Field-Flow-Fractionation (FFF)
17.5.2 Analytical Ultracentrifugation
17.5.3 Differential Mobility Analyzer (DMA)
17.5.4 Low Pressure Impactor (LPI)
17.6 Multiparametric Particle Characterization
17.6.1 Aerosol Photoemission Spectroscopy (APES)
17.6.2 Multidimensional NTA on Nanosuspensions
17.6.3 Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
17.7 Summary
Part V Characterization of Metal Oxide Nanoparticles with Modelling
18 Atomistic Modeling of Oxide Nanoparticles
Keith McKenna
18.1 Introduction
18.2 Methods
18.2.1 Interatomic Potentials
18.2.2 First Principles Methods
18.2.3 QM/MM (or Embedded Cluster) Methods
18.3 Structure of Nanoparticles
18.3.1 Kinetic vs. Thermodynamic Approaches
18.3.2 0D, 1D, 2D, and 3D Defects in Nanoparticles
18.3.3 Interfaces Between Nanoparticles
18.4 Electronic Properties
18.4.1 Density of States
18.4.2 Ionization Energies and Electron Affinities
18.4.3 Optical Absorption Spectra
18.4.4 Electron Paramagnetic Resonance
18.5 Summary
19 Modeling of Reactions at Oxide Surfaces
Henrik Grönbeck
19.1 Introduction
19.2 Computational Considerations
19.2.1 First Principles Calculations
19.2.2 Ab Initio Thermodynamics
19.2.3 Kinetic Modeling of Surface Reactions
19.3 Some Features of Reactions on Metal Oxide Surfaces
19.4 Adsorbate Pairing
19.4.1 Cooperative Adsorption
19.4.2 Effects of Electronic-Pairing in Modeling of Surface Reactions
19.4.3 Kinetic Modeling of Reactions at Oxide Surfaces
19.4.4 Trans-Ligand Effects
19.5 Reactions at Nanoparticles
19.5.1 Trends in Adsorption Properties
19.6 Conclusions
20 Mesoscale Modelling of Nanoparticle Formation
Eirini Goudeli
20.1 Introduction
20.2 Nanoparticle Characterization
20.2.1 Agglomerate Radii
20.2.2 Fractal Dimension and Mass-Mobility Exponent
20.2.3 Dynamic Shape Factor
20.2.4 Relative Shape Anisotropy
20.3 Coarse-Grained Molecular Dynamics
20.4 Monte Carlo Simulations
20.5 Discrete Element Method
20.5.1 Collision Frequency Function
20.6 Particle Dynamics
20.7 Concluding Remarks
Part IV Nanoparticles in Biological Environments
21 Biological Activity of Metal Oxide Nanoparticles
Martin Himly, Mark Geppert, and Albert Duschl
21.1 Bio-Nano Interaction
21.2 Interaction of Nanoparticles with Cells
21.2.1 Recognition of Nanoparticles by Cells
21.2.1.1 Uptake of Nanoparticles into Cells
21.2.1.2 Intracellular Fate and Interactions
21.3 Uptake Routes of Nanoparticles into the Body and Their Fate There
21.4 Biological Test Methods for Assessing Biological Activities and Hazards of Nanoparticles
21.4.1 In Vitro Methods
21.4.2 In Vivo Methods
21.4.3 Biological Endpoints
21.5 Exposure of Humans
21.5.1 Intentional Exposure
21.5.2 Unintentional Exposure
21.6 Nanoparticles in the Environment
21.7 Understanding and Regulating Risk
Part VII Case Studies
22 The Properties of Iron Oxide Nanoparticle Pigments
Robin Klupp Taylor
22.1 Introduction
22.2 Properties of Pigments with a Focus on Iron Oxides
22.2.1 Introduction by Way of a Commercial Pigment Example
22.2.2 Colorimetric Properties of Pigment Films
22.2.3 Pigments as Particle Based Optical Materials: General Considerations
22.2.4 Radiative Transfer in a Pigment Film: Kubelka-Munk Theory
22.2.5 Optical Properties of Metal Oxides for Color Pigments
22.2.5.1 Defining the Complex Refractive Index
22.2.5.2 Measuring the Complex Refractive Index
22.2.6 Microscopic Models for Light Scattering
22.2.6.1 Particles Much Smaller Than the Wavelength of Light
22.2.6.2 Spherical Particles Similar in Size or Larger Than the Wavelength of Light (Lorenz-Mie Theory)
22.2.6.3 Simulating Pigment Color Based on Spherical Particles
22.2.6.4 Simulating Pigment Color Based on Nonspherical Particles
23 Zinc Oxide Nanoparticles for Varistors
Oliver Diwald
23.1 Introduction
23.2 Principle of Operation and Microstructure
23.3 Varistor Manufacturing: The Conventional Approach in Industry
23.4 Why Use Synthetic ZnO Nanoparticle Powders as Raw Materials
23.5 Defect Engineering and Electronic Properties
23.6 Impurity Admixture for Microstructure Engineering
23.7 Synthesis of Varistor Nanoparticle Powders
23.8 Formulation and Shaping of ZnO Powders and Dispersions
23.9 Sintering
23.9.1 Alternative Approaches for the Sintering of Nanostructured ZnO Green Bodies
23.10 Cold Sintering and Ceramic-Polymer Composite Varistors
23.11 Concluding Remarks
24 Metal Oxide Nanoparticle-Based Conductometric Gas Sensors
Thomas Berger
24.1 Introduction
24.2 Working Principle of Metal Oxide Particle-Based Conductometric Gas Sensors
24.3 Porous Layers Consisting of Loaded and Doped Metal Oxide Particles
24.3.1 Loaded Metal Oxide Particles
24.3.2 Doped Metal Oxide Particles
24.4 Metal Oxide Nanoparticle-Based Sensing Layers
24.5 Fabrication of Nanoparticle-Based Porous Thick Film Sensing Layers
24.5.1 Layer Deposition Involving Particle Dispersions
24.5.1.1 Synthesis of Sensing Materials
24.5.1.2 Screen Printing
24.5.1.3 Inkjet Printing
24.5.1.4 Drop Coating
24.5.2 Flame Spray Pyrolysis
24.6 Nanostructured Conductometric Gas Sensors for Breath Analysis
