Al-based Energetic Nano Materials: Design, Manufacturing, Properties and Applications (Nanotechnologies for Energy Recovery)

Over the past two decades, the rapid development of nanochemistry and nanotechnology has allowed the synthesis of various materials and oxides in the form of nanopowders making it possible to produce new energetic compositions and nanomaterials. This book has a bottom-up structure, from nanomaterials synthesis to the application fields. Starting from aluminum nanoparticles synthesis for fuel application, it proposes a detailed state-of-the art of the different methods of preparation of aluminum-based reactive nanomaterials. It describes the techniques developed for their characterization and, when available, a description of the fundamental mechanisms responsible for their ignition and combustion. This book also presents the possibilities and limitations of different energetic nanomaterials and related structures as well as the analysis of their chemical and thermal properties. The whole is rounded off with a look at the performances of reactive materials in terms of heat of reaction and reactivity mainly characterized as the self-sustained combustion velocity. The book ends up with a description of current reactive nanomaterials applications underlying the promising integration of aluminum-based reactive nanomaterial into micro electromechanical systems. Cover 1 Title Page 5 Copyright 6 Contents 7 Introduction 11 Acknowledgements 13 1: Nanosized Aluminum as Metal Fuel 15 1.1. Al nanoparticles manufacturing 16 1.1.1. Vapor-phase condensation methods 16 1.1.1.1. Electrical explosion and vaporization wire 16 1.1.1.2. Other techniques 20 1.1.2. Wet chemistry 20 1.1.3. Mechanical methods 21 1.2. Example of Al nanoparticles passivation technique 22 1.2.1. Metallic coating 23 1.2.2. Organic coating 23 1.3. Characterization of Al nanoparticles properties 25 1.3.1. Light scattering methods 26 1.3.2. Gas adsorption method: specific surface measurement, BET diameter 27 1.3.3. Thermal analysis: purity or aluminum content percentage and oxide thickness 27 1.3.4. Chemical analysis 29 1.4. Oxidation of aluminum: basic chemistry and models 30 1.4.1. Initial stage of aluminum oxidation from first principles calculations 30 1.4.2. Thermodynamic modeling of Al oxidation under low heating rate 32 1.4.2.1. Fixed ignition temperature model 32 1.4.2.2. Stress in the oxide layer model 33 1.4.2.3. Oxidation growth modeling 33 1.4.2.4. Diffusion based on phase transformation processes 35 1.5. Why incorporate Al nanoparticles into propellant and rocket technology? 37 1.5.1. Reduction of the melting point 38 1.5.2. Increase in the reactivity 39 2: Applications: Al Nanoparticles in Gelled Propellants and Solid Fuels 41 2.1. Gelled propellants 41 2.2. Solid propellants 43 2.3. Solid fuel 45 3: Applications of Al Nanoparticles: Nanothermites 47 3.1. Method of preparation 49 3.1.1. Ultrasonic nanopowder mixing 50 3.1.2. Rapid expansion of a supercritical dispersion 52 3.1.3. Molecular self-assembly of nanoparticles 53 3.2. Key parameters 56 3.2.1. The bulk density, theoretical density and compaction 56 3.2.2 The stochiometry 58 3.2.3. The size of Al and oxidizer particles 60 3.2.4. The passivation layer 63 3.3. Pressure generation tests 64 3.4. Combustion tests 66 3.4.1 Open tray experiments 66 3.4.2. Optical temperature measurement: spectroscopy 67 3.4.3. Photodiodes 68 3.4.4. Confined combustion tests 68 3.5. Ignition tests 70 3.5.1. Impact ignition 70 3.5.2. High-rate heating (106–107 °C/s) 71 3.5.3. Low and uniform heating (10–100 °C/s) 71 3.6. Electrostatic discharge (ESD) sensitivity tests 72 4: Other Reactive Nanomaterials and Nanothermite Systems 77 4.1. Sol–gel materials 77 4.2. Reactive multilayered foils 80 4.2.1. Bimetallic multilayered foils 81 4.2.1.1. Method of fabrication 81 4.2.1.2. Properties and performances 84 4.2.2. Thermite multilayered foils 86 4.2.2.1. Method of fabrication 87 4.2.2.2. Properties and performances 89 4.2.3. Summary 91 4.3. Dense reactive materials 91 4.3.1. Arrested reactive milling 92 4.3.2. Cold-spray consolidation 95 4.4. Core–shell structures 97 4.5. Reactive porous silicon 100 4.6. Other energetic systems 102 5: Combustion and Pressure Generation Mechanisms 105 5.1. General view of Al particle combustion: micro versus nano, diffusion-based kinetics 107 5.2. Stress in the oxide layer and shrinking core model 109 5.3. Aluminum oxidation through diffusion-reaction mechanisms 111 5.4. Melt-dispersion mechanism 113 5.5. Gas and pressure generation in nanothermites 114 5.5.1. Thermodynamic models 114 5.5.2. Application to Al/CuO 117 6: Applications 121 6.1. Reactive bonding 122 6.2. Microignition chips 124 6.3. Microactuation/propulsion 127 6.3.1. High energetic actuators 127 6.3.2. Fast impulse nanothermite thrusters 127 6.3.3. Smooth actuators 130 6.4. Material processing and others 133 Conclusions 135 Bibliography 139 Index 163 Over the past two decades, the rapid development of nanochemistry and nanotechnology has enabled the synthesis of various materials and oxides in the form of nanopowders, making it possible to produce new energetic compositions and nanomaterials. This book has a bottom-up structure, moving from the synthesis of nanomaterials through to the fields of application. Starting from the synthesis of aluminum nanoparticles for fuel applications, the author provides a detailed state of the art of the different methods for the preparation of aluminum-based reactive nanomaterials. She then goes on to describe the techniques developed for their characterization and provides a description of the fundamental mechanisms responsible for their ignition and combustion. The possibilities and limitations of different energetic nanomaterials and related structures are also provided,along with the analysis of their chemical and thermal properties. The book proceeds by studying the performances of reactive materials in terms of the enthalpy of reaction and reactivity, mainly characterized as the self-sustained combustion rate, before concluding with a description of current reactive nanomaterial applications underlying the promising integration of aluminum-based reactive nanomaterials into MicroElectroMechanicalSystems