Nanostructure Control of Materials

R H J Hannink, A J Hill

• Publisher: Woodhead Publishing
• Year: 2006
• ISBN:
  9781845691189
• Topic: Tecnologia e ingegneria
• Subtopic: Ingegneria elettronica e telecomunicazioni

The ability to measure and manipulate matter on the nanometer level is making possible a new generation of materials with enhanced mechanical, optical, transport and magnetic properties. This important book summarises key developments in nanotechnology and their impact on the processing of metals, polymers, composites and ceramics.After a brief introduction, a number of chapters discuss the practical issues involved in the commercial production and use of nanomaterials. Other chapters review ways of nanoengineering steel, aluminium and titanium alloys. Elsewhere the book discusses the use of nanoengineered metal hydrides to store hydrogen as an energy source, and the development of nanopolymers for batteries and other energy storage devices. Other chapters discuss the use of nanotechnology to enhance the toughness of ceramics, the production of synthetic versions of natural materials such as bone, and the development of nanocomposites.Nanostructure control of materials is an ideal introduction to the ways nanotechnology is being used to create new materials for industry. It will be welcomed by R&D managers in such sectors as automotive engineering as well as academics working in this exciting area.

• Reviews key developments in nanotechnology and their impact on various materials
• Edited by leading experts in the field

1

Nanoparticle technologies and applications

P. CASEY, CSIRO, Australia

Publisher Summary

In recent years, the nanotechnology concept has stimulated the collective imagination of the scientific, engineering, and business communities. If its perceived potential can be realized, then it can arguably be regarded as a “disruptive” technology. Whether or not this occurs remains to be seen. In the meantime, the lure of what may be possible, by exploring and developing science and engineering at the nano-level, has reinvigorated the efforts of these practitioners across almost the entire spectrum of disciplines. Applications that may fundamentally impact in many aspects of human lives appear to be as broad as the imagination. While this new outlook is refreshing and exciting, what has become clear is that the breadth and depth of information surrounding, it is fast becoming virtually unmanageable. This chapter presents a general attempt to broadly scope technologies involved in nanoparticle production and discusses the range of methods used. In general, there are two approaches to nanoparticle production that are commonly referred to as top-down and bottom-up. Top-down nanoparticles are generated from the size reduction of bulk materials. They generally rely on physical, the combination of physical and chemical, electrical, or thermal processes for their production. Such methods include high-energy milling, mechano-chemical processing, electro-explosion, laser ablation, sputtering, and vapor condensation. Bottom-up approaches generate nanoparticles from the atomic or molecular level and thus are predominantly chemical processes. Commonly used techniques are crystallization/precipitation, sol-gel methods, chemical vapor deposition, and self-assembly routes. Some processes may use a combination of both.

1.1 Introduction

In recent years, the nanotechnology concept has stimulated the collective imagination of the scientific, engineering and business communities. If its perceived potential can be realised then it can arguably be regarded as a ‘disruptive’ technology. Whether or not this occurs remains to be seen. In the meantime, the lure of what may be possible, by exploring and developing science and engineering at the nano-level, has reinvigorated the efforts of these practitioners across almost the entire spectrum of disciplines. Applications that may fundamentally impact in many aspects of our lives appear to be as broad as the imagination. While this new outlook is refreshing and exciting, what has become clear is that the breadth and depth of information surrounding it is fast becoming virtually unmanageable.

This chapter represents a general attempt to broadly scope technologies involved in nanoparticle production so that the reader has an appreciation of the range of methods used. The reader is refferred to references [1–11] as a useful starting point for further reading. Later chapters will cover specific areas in much greater detail than is presented here. As such it is a broad survey, which limits itself to the production of nanoparticles (<100 nm) and does not encompass the design, characterisation or application of what is generally termed structures, devices or systems. It focuses on 2 and 3D nano-particulate materials rather than one-dimensional materials such as films, engineered surfaces or positionally assembled nanoparticles. Table 1.1 presents examples of these.

Table 1.1

Examples of two- and three-dimensional nanoparticles

Two dimensions (few nm in diameter, length up to several cm)	Three dimensions (<100 nm in diameter)
carbon nanotubes (single and multi wall)	nanoparticles (particles
inorganic nanotubes	< 100 nm in diameter)
carbon and inorganic nanorods	fullerenes (C60)
nanoplatelets	dendrimers
nanofibrils	quantum dots
nanowires
biopolymers

In general, there are two approaches to nanoparticle production that are commonly referred to as ‘top-down’ and ‘bottom-up’. ‘Top-down’ nanoparticles are generated from the size reduction of bulk materials. They generally rely on physical, the combination of physical and chemical, electrical or thermal processes for their production. Such methods include high-energy milling, mechano-chemical processing, electro-explosion, laser ablation, sputtering and vapour condensation. ‘Bottom-up’ approaches generate nanoparticles from the atomic or molecular level and thus are predominantly chemical processes. Commonly used techniques are crystallisation/precipitation, sol-gel methods, chemical vapour deposition and self-assembly routes. Some processes may use a combination of both.

Either approach may be performed in all three states of matter, i.e., vapour, solid or liquid (or combination of these) and the limits to the physical size of nanoparticles produced by either approach is converging and may overlap. Consequently, the choice of particle size, from a product design perspective, is directly influenced by process economics, capability to supply and the adequacy and type of performance required in the target application. To meet performance criteria, not only does the nanoparticle material have to have (or be able to impart) desired functionality but also that functionality must be predictable and reliable. The latter is often determined by extrinsic factors such as the degree of dispersion, the level of contamination and the working environment. Apart from characteristic size range significant commonality is not apparent between the technologies used to produce nanoparticles although some techniques appear to be more flexible than others. Table 1.2 summarises the range of production processes by type and will be used as the basis for the following...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• Contributor contact details
• Foreword
• Acknowledgements
• Introduction: special properties resulting from nanodimensionality
• Chapter 1: Nanoparticle technologies and applications
• Chapter 2: Nanometric architectures: emergence of efficient non-crystalline atomic organization in nanostructures
• Chapter 3: Nanostructure characterisation using electron-beam techniques
• Chapter 4: Organic-inorganic nanocomposite membranes for molecular separation processes
• Chapter 5: Developing fast ion conductors from nanostructured polymers
• Chapter 6: Nanostructures in biological materials
• Chapter 7: Mechanical behavior of metallic nanolaminates
• Chapter 8: Preparation of monolithic nanocrystalline ceramics
• Chapter 9: Nanoengineering of metallic materials
• Chapter 10: Using magnetic resonance to study nanoprecipitation in light metal alloys
• Chapter 11: Nanocrystalline light metal hydrides for hydrogen storage
• Chapter 12: Nanofabrication
• Index