Green Nanotechnology : Solutions for Sustainability and Energy in the Built Environment

A first step in developing a clean and sustainable future is to think differently about everyday products, in particular how they influence energy use. **Green Nanotechnology: Solutions for Sustainability and Energy in the Built Environment** explores the science and technology of tiny structures that have a huge potential to improve quality of life while simultaneously achieving reductions in the use of fossil fuels. This book examines energy flows in nature and how the optical properties of materials can be designed to harmonize with those flows. It then discusses the properties that can be achieved in real materials to take advantage of nature’s energy flows. The authors cohesively examine a number of topics, highlighting their applications and the significance of their nano features. They provide a cursory discussion of well-reviewed subjects such as nanostructured solar cells and turn their attention to timely topics such as methods for preventing excessive temperature and approaches to passive cooling. The book identifies key materials and elucidates how their properties can be understood in terms of contemporary materials physics and chemistry. It concludes with a detailed description of a scenario for future buildings that use much less energy while also providing better comfort. A valuable side effect of most nanotechnologies is that they inherently put us in closer touch with the natural world. With broad coverage of how nanoparticles impact energy use in the built environment, this book opens readers’ eyes to a fascinating vision of how technology and nanoscience can merge and lead to commodity-scale products that help preserve our planet. FM EBK1420085327-1.pdf 1 GREEN NANOTECHNOLOGY: Solutions for Sustainability and Energy in the Built Environment 1 GREEN NANOTECHNOLOGY: Solutions for Sustainability and Energy in the Built Environment 2 Contents 4 Preface 12 EBK1420085327-2.pdf 23 Chapter1: Green Nanotechnology: Introduction and Invitation 23 1.1 What Is Nanotechnology? 23 1.2 What Is Green Nanotechnology? 26 1.3 Some Basic Issues in Nanoscience 27 1.4 Nanoscience, Dimensionality, and Thin Films 33 1.5 Outdoing Nature in Exploiting Complexity 34 1.6 Energy Supply and Demand 36 1.7 Energy and Development 42 References 43 EBK1420085327-3.pdf 47 Chapter 2: In Harmony with the Environment: Nature’s Energy Flows and Desired Materials Properties 47 2.1 Global Energ y Flows 48 2.2 Radiation in Our Ambience : An Overview 50 2.3 Interaction between Radiation and Materials 55 2.3.1 Fundamentals Based on Energy Conservation 55 2.3.2 Directionality and Polarization Dependence 56 2.4 Beam and Diffuse Radiation 58 2.4.1 General Considerations 58 2.4.2 Energy Flows in Diffuse and Nonparallel Radiation Beams 59 2.5 Hemispherical Absorptance 64 2.6 Solar and Daylighting Performance Parameters 66 2.7 Thermal Radiation and Spectral Properties of the Atmosphere 67 2.7.1 Blackbody Emittance 68 2.7.2 The Sky Window 69 2.8 Dynamical Environmental Properties 72 2.8.1 General Considerations 72 2.8.2 Solar Energy and Daylight Dynamics: The Sun's Path 73 2.9 Materials for Optimized Use of the Spectral , Directional , and Dynamical Properties of Solar Energ y and Sky Radiation 75 2.9.1 Opaque Materials 77 2.9.2 Transparent Materials 79 2.9.3 Other Generic Classes of Optical Properties for Radiation Control 80 2.10 Thermal and Densit y Gradients in the Atmosphere and Oceans 82 2.11 Performance of Energ y Systems : Thermod ynamics and Value 83 References 86 EBK1420085327-4.pdf 89 Chapter 3: Optical Materials Science for Green Nanotechnology: The Basics 89 3.1 Light and Nanostructures 91 3.1.1 Local Fields and Far Fields 91 3.1.2 Refractive Index and Absorption Coefficient 92 3.2 Spectral Properties of Uniform Materials 95 3.2.1 Insulators and Liquids 96 3.2.2 Conductors, Semiconductors, and Superconductors 97 3.2.3 Chromogenic Materials 98 3.3 Plasmonic Materials in General 99 3.4 Materials for Electron - Based Plasmonics : Mirrors for Visible and Infrared Light 101 3.5 Ionic - Based Materials with Narrow - Band Infrared Properties 107 3.5.1 Plasmonics Once Again 107 3.5.2 Phonon Absorption 109 3.5.3 Infrared Transparency 110 3.6 Generic Classes of Spectrall y Selective Materials 110 3.7 Thin Films for Controlling Spectral Properties and Local Light Intensities 111 3.8 Nanoparticle Optics 114 3.8.1 Transparent and Translucent Materials 114 3.8.2 Some Basic Models 116 3.9 Optical Homogenization of Nanocomposites 120 3.9.1 Models for Particle- and Inclusion- Based Composites 121 3.9.2 Invisibility, Effective Medium Models, and Critical Percolation 122 3.9.3 Core- Shell Random Unit Cells and Actual Core- Shell Particles 126 3.10 Surface Plasmon Resonances in Films , Particles , and " Rectennas " 129 3.11 Temporary " Storage " of Light at Resonances and in Evanescent Fields 133 3.11.1 General Considerations 133 3.11.2 Evanescent Optical Fields and How They Can Be Used 135 References 138 EBK1420085327-5.pdf 144 Chapter 4: Visual Indoors–Outdoors Contact and Daylighting Windows 144 4.1 General Introduction 145 4.1.1 Strategies for Energy Efficiency 146 4.1.2 Uncoated Glass and Plastic Foil 147 4.2 Spectral Selectivit y: The Energ y Efficienc y That Is Possible 149 4.3 Spectral Selectivit y of Noble - Metal - Based Films 153 4.3.1 Thin Metal Films Are Not Bulk- Like 154 4.3.2 Very Thin Metal Films Are Nanomaterials 155 4.3.3 Toward a Quantitative Theoretical Model for the Optical Properties 158 4.3.4 Multilayer Films for Spectrally Selective Windows 162 4.4 Spectral Selectivit y of Oxide - Semiconductor - Based Films 166 4.4.1 Some Characteristic Properties 168 4.4.2 Typical Nanostructures of ITO Films 169 4.4.3 Theoretical Models for the Optical and Electrical Properties of ITO Films 172 4.4.4 Computed Optical Properties 175 4.5 Spectral Selectivit y: Novel Developments for Films and Foils 177 4.5.1 Silver- Based Nanowire Meshes 177 4.5.2 Carbon Nanotubes and Graphene 179 4.5.3 Foils with Conducting Nanoparticles 181 4.5.4 " Holey" Metal Films 182 4.5.5 Photonic Crystals 183 4.6 Optimized Angular Properties : The Energ y Efficienc y That Is Possible 184 4.7 Angular Selectivit y of Films with Inclined Columnar Nanostructures 187 4.8 Chromogenics : The Energ y Efficienc y That Is Possible 188 4.9 Photochromics 196 4.10 Thermochromics 198 4.10.1 Metal- Insulator Transition and Its Nanofeatures in VO2 199 4.10.2 Thermochromism in VO2- Based Films, and How to Adjust the Metal- Insulator Transition 200 4.10.3 How to Enhance the Luminous Transmittance in VO2 204 4.11 Electrochromics 208 4.11.1 How Do Electrochromic Devices Work? 209 4.11.2 Facile Ion Movement Due to Favorable Nanostructures 211 4.11.3 What Causes the Optical Absorption? 214 4.11.4 Some Device Properties 214 4.11.5 Alternative Electrochromic Devices 217 References 220 EBK1420085327-6.pdf 227 Chapter 5: Electric Lighting and Daylighting: Luminaires 227 5.1 Lighting : Past , Present , and Future 228 5.2 Daylighting Technolog y: The " Cool " Option 232 5.2.1 Roof Glazing and Skylights 233 5.2.2 Mirror Light Pipes 236 5.2.3 Daylight Redirecting Structures for Façades 241 5.3 Dielectric Mirrors Based on Nanostructure 244 5.4 Luminescent Solar Concentrators for Daylighting and Solar Power 248 5.4.1 Devices for Generating Daylight- Like Radiation 248 5.4.2 Devices with Solar Cells and Mirrors 253 5.4.3 Light Trapping in Light Guides: Getting It All Out 253 5.5 Light - Diffusing Transmitting Materials 256 5.5.1 Polymer Diffusers 257 5.5.2 End- Lit Long Continuous Light Sources 260 5.5.3 Light Extraction from Light Pipes and in LCD Displays 264 5.6 Advanced Electronic Lighting Concepts 265 5.6.1 Semiconductor Light- Emitting Diodes 266 5.6.2 Organic Light- Emitting Diodes 269 5.6.3 Nanostructures for Improved LED Performance 270 5.6.4 Emerging Lamp Technologies 274 5.6.5 Concluding Remarks 275 References 276 EBK1420085327-7.pdf 281 Chapter 6: Heat and Electricity: Solar Collectors and Solar Cells 281 6.1 Solar Thermal Materials and Devices 281 6.1.1 Spectral Selectivity and Its Importance 283 6.1.2 Principles for Spectral Selectivity 285 6.1.3 Selectively Solar- Absorbing Coatings Based on Nanoparticles: Some Practical Examples 289 6.1.4 Colored Absorbers and Paints: Novel Developments 297 6.2 Photovoltaic Materials and Devices 299 6.2.1 Technology Overview 301 6.2.2 Nanofeatures for Boosting the Efficiency of Silicon- Based Solar Cells 304 6.2.3 Dye- Sensitized Solar Cells 308 6.2.4 Organic Solar Cells 312 References 317 EBK1420085327-8.pdf 322 Chapter 7: Coolness: High-Albedo Surfaces and Sky Cooling Devices 322 7.1 Two Cooling Strategies 324 7.1.1 High- Albedo Surfaces 324 7.1.2 Sky Cooling 326 7.2 Cit y Heating , Global Cooling , and Summer Blackouts 326 7.2.1 Urban Heat Islands 326 7.2.2 Global Cooling by Increased Albedo 329 7.2.3 Avoiding Summer Blackouts 331 7.3 High - Albedo Paints for Cool Buildings 332 7.3.1 How Cool Can a Solar Exposed Roof Get? 333 7.3.2 Colored Paints with High Solar Reflectance 337 7.3.3 Mechanisms and Nanostructures for Colored " Cool" Paints 338 7.4 Sky Cooling to Subambient Temperatures 341 7.4.1 Sky Radiance 343 7.4.2 Spectral Selectivity and Sky Cooling: Idealized Surfaces 346 7.4.3 Calculated Cooling for Ideal and Practical Materials 348 7.4.4 Some Practical Surfaces for Sky Cooling: Bulk- Type Solids 351 7.4.5 Nanotechnology for Optimum Sky Radiators: Computed and Measured Data 351 7.4.6 Practical Sky Cooling: Systems and Data 356 7.4.7 Amplifying Sky Cooling with Heat Mirrors 361 7.4.8 Impact of Solar Irradiance on Sky Cooling 364 7.5 Water Condensation Using Sky Cooling 365 7.6 A Role for Cooling and Waste Heat in Electric Power Generation 367 7.7 Electronic Cooling and Nanotechnolog y 369 7.8 Whither Cooling ? 372 7.8.1 Some Environmental and Health- Related Benefits 372 7.8.2 Cooling Plus 372 References 373 EBK1420085327-9.pdf 379 Chapter 8: Supporting Nanotechnologies: Air Sensing and Cleaning, Thermal Insulation, and Electrical Storage 379 8.1 Air Qualit y and Air Sensing 379 8.1.1 The Sick Building Syndrome 379 8.1.2 Gas Sensing with Nanoporous Metal Oxides: General 381 8.1.3 Gas Sensing with Nanoporous Metal Oxides: Illustrative Examples 383 8.2 Photocatal ysis for Cleaning 386 8.2.1 General 386 8.2.2 Self- Cleaning Surfaces 390 8.2.3 Air Purification 395 8.3 Thermal Insulation with Nanomaterials 396 8.3.1 Thermal Conductance of Porous and Nanoporous Materials 397 8.3.2 Vacuum Insulation Panels 399 8.3.3 Silica Aerogel 400 8.4 Green Energ y Storage 401 8.4.1 Energy Storage: Survey of a " Missing Link" 401 8.4.2 Electrical Storage Using Electrochemistry 403 8.4.3 Electrochemical Super- and Ultracapacitors 405 8.4.4 Nanomaterials for Advanced Batteries 407 References 411 EBK1420085327-10.pdf 417 Chapter 9: Conclusions: Nanotechnologies for a Sustainable Future 417 9.1 Energy and the Future 417 9.2 New Technologies and Growing Uptake of Proven Technologies 420 9.3 Toward a " Nanoworld " 421 References 428 EBK1420085327-11.pdf 430 Appendix 1: Thin-Film Deposition 430 A1.1 Overview of Major Thin - Film Technologies 430 A1.2 Sputter Deposition for Making Nanostructured Thin Films 436 A1.3 Nanoparticle - Based Coatings 439 References 442 EBK1420085327-12.pdf 445 Appendix 2: Abbreviations,Acronyms, and Symbols 445 EBK1420085327-13.pdf 453 Color Insert 453 This Book Explores The Science And Technology Of Tiny Structures That Have A Huge Potential To Improve Quality Of Life While Simultaneously Achieving Reductions In The Use Of Fossil Fuels. It Examines Energy Flows In Nature And How The Optical Properties Of Materials Can Be Designed To Harmonize With Those Flows. It Then Discusses The Properties That Can Be Achieved In Real Materials To Take Advantage Of Nature's Energy Flows. Green Nanotechnology: Introduction And Invitation -- In Harmony With The Environment: Nature's Energy Flows And Desired Materials Properties -- Optical Materials Science For Green Nanotechnology: The Basics -- Visual Indoors-outdoors Contact And Daylighting: Windows -- Electric Lighting And Daylighting: Luminaries -- Heat And Electricity: Solar Collectors And Solar Cells -- Coolness: High-albedo Surfaces And Sky Cooling Devices -- Supporting Nanotechnologies: Air Sensing And Cleaning, Thermal Insulation, And Electrical Storage -- Conclusions: Nanotechnologies For A Sustainable Future. Geoffrey B. Smith, Claes G. Granqvist. Includes Bibliographical References And Index.