Synthesis of Inorganic Nanomaterials

Advances and Key Technologies

Sneha Bhagyaraj, Oluwatobi Samuel Oluwafemi, Nandakumar Kalarikkal, Sabu Thomas, Sneha Mohan Bhagyaraj

• Publisher: Woodhead Publishing
• Year: 2018
• Print ISBN: 9780081019757
• eBook ISBN: 9780081019764
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Synthesis of Inorganic Nanomaterials: Advances and Key Technologies discusses the latest advancements in the synthesis of various types of nanomaterials. The book's main objective is to provide a comprehensive review regarding the latest advances in synthesis protocols that includes up-to-date data records on the synthesis of all kinds of inorganic nanostructures using various physical and chemical methods. The synthesis of all important nanomaterials, such as carbon nanostructures, Core-shell Quantum dots, Metal and metal oxide nanostructures, Nanoferrites, polymer nanostructures, nanofibers, and smart nanomaterials are discussed, making this a one-stop reference resource on research accomplishments in this area. Leading researchers from industry, academia, government and private research institutions across the globe have contributed to the book. Academics, researchers, scientists, engineers and students working in the field of polymer nanocomposites will benefit from its solutions for material problems. - Provides an up-to-date data record on the synthesis of all kinds of organic and inorganic nanostructures using various physical and chemical methods - Presents the latest advances in synthesis protocols - Includes the latest techniques used in the physical and chemical characterization of nanomaterials - Covers the characterization of all the important materials groups, such as carbon nanostructures, core-shell quantum dots, metal and metal oxide nanostructures, Nano ferrites, polymer nanostructures and nanofibers

Chapter 1

Nanotechnology: The Science of the Invisible

Sneha Mohan Bhagyaraj⁎; Oluwatobi Samuel Oluwafemi⁎^{,† ⁎}Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein, Johannesburg, South Africa
^†Department of Applied Chemistry, University of Johannesburg, Doornfontein, Gauteng, South Africa

Abstract

Research on nanomaterials has stimulated a lot of interest over the past decades due to their unique properties and vast utilities in biological, medical, electronic, and optoelectronic applications. This chapter will explore the origin of the nanotechnology concept, which can be traced back to about half a century ago when people thought the smallest man-made structure was an optical fiber. The origin of the conceptions related to nanotechnology (which includes definition of nanotechnology, the main researchers associated with it, and some terminology) will also be included. Various milestones during the development of nanotechnology also will be mentioned here. Various synthesis techniques for nanostructures will be outlined. Properties of materials at their nano-size range will be discussed in detail. A brief note on the applications of nanotechnology in various fields will be discussed towards the end of the chapter.

Keywords

Nanomaterials; History; Synthesis; Quantum confinement; Properties

1.1 Concept of Nanotechnology

In 1959, physicist and Nobel laureate Richard Feynman presented, “There's Plenty of Room at the Bottom,” at a meeting of the American Physical Society where the concept of nanotechnology was introduced for the first time—without naming it as such [1]. In his famous speech, Feynman talked about the problem of manipulating and controlling things on a small scale. He put forward a challenge to physicists and offered a prize of $1000 to the first one to make an operational electric motor, “a rotating electric motor which can be controlled from the outside and, not counting the lead-in wires, …[no larger than a] 1/64^th- inch cube.” Feynman had hoped his reward would stimulate some new fabrication technology, but to his surprise, after 1 year, Bill McLellan (using his amateur radio skills) built the 2000-rpm motor which weighed 250 μg by hand using tweezers and a microscope. In the almost 50 years since, after so many advanced developments in the field of microelectromechanical systems, researchers have begun exploring another level of miniaturization—nanoelectromechanical systems.

Nanotechnology is the manipulation of matter at a molecular or atomic level in order to produce novel materials and devices with new extraordinary properties and having close links to nanoscience. One nanometer is a billionth of a meter, or 10^{− 9} of a meter, which is unimaginably small. Nanotechnology is a merging of multiple scientific disciplines including biology, physics, chemistry, medicine, and engineering, and the combination of knowledge to tailor materials at the range of 1–100 nm (10^{− 9} m). The innovative and revolutionary nature of nanotechnology is attributed to quantum mechanics principles [2]. The behavior of matter changes significantly when the surface-area-to-volume ratio increases so dramatically. The behavior of the material is now under the control of quantum laws rather than classical physics. This fact gives the nano-structured material new abilities and properties that may be more favorable than those of the bulk material version. For example, some polymers are insulators in the bulk form, but become semiconductors in their nanoscale form.

1.2 History of Nanotechnology

The development of the central concepts of nanotechnology dates back to prehistoric times when early humans made use of naturally occurring, nanoscale elements. For example, nano-sized carbon molecules integrated nicely with the more porous rock surface of cave walls to remain embedded for thousands of years. The principle of nanotechnology (the process and appreciation of miniaturization) is not new to the electronic or even the postindustrial eras, either. Although modern nanoscience and nanotechnology are considered to be quite new, nanoscale materials have been used for centuries. Stained glass windows of medieval churches built hundreds of years ago used alternate-sized gold and silver particles, and the process used to create these beautiful works of art changed the composition and structure of the materials in their nanostates, resulting in the windows’ interesting colors. Researchers have recently begun exploring a wide variety of techniques to enhance the properties of nanomaterials and give them qualities such as higher strength, lighter weight, increased control of light spectrum, and greater chemical reactivity than their large-scale counterparts.

All the developments in nanotechnology began after 1959 when theoretical physicist Richard Feynman asked a couple of questions. He put forward the possibility of writing all 24 volumes of the Encyclopedia Britannica on the head of a pin. His colleagues in the American Physical Society at the California Institute of Technology (Caltech) were puzzled but intrigued. The talk delivered by Feynman, published in February of 1960 in Caltech's Engineering and Science, is considered the first introduction to the concept of nanotechnology. In 1974, Tokyo Science University professor Norio Taniguchi coined the term, “nanotechnology.” His main concern was manufacturing materials with nanometer tolerances, and two of his works mentioned concepts related to nanomaterials, Nanotechnology: Integrated Processing Systems for Ultra-Precision and Ultra-Fine Products and On the Basic Concept of Nano-Technology. Table 1.1 lists all notable developments in the field of nanotechnology after the talk by Feynman.

Table 1.1

Major Developments in the Field of Nanotechnology From 1959 to 2011

Year	Development
1959	Feynman gives after-dinner talk describing molecular machines built with atomic precision
1974	Taniguchi uses term “nanotechnology” in paper on ion-sputter machining
1977	Drexler originates molecular nanotechnology concepts at MIT
1981	First technical paper on molecular engineering for building with atomic precision STM invented
1985	Buckyball discovered
1986	First book published, AFM invented, first organization formed
1989	IBM logo spelled in individual atoms
1991	Carbon nanotube discovered
1997	First company founded: Zyvex First design of nanorobotic system
1998	First DNA-based nanomechanical device
1999	First nanomedicine book published
2000	President Clinton announces US National Nanotechnology Initiative First state research initiative: $100 million in California
2001	First report on nanotech industry US announces first center for military applications
2002	First nanotech industry conference, regional nanotech efforts multiply
2003	Congressional hearings on societal implications Call for balancing NNI research portfolio Drexler/Smalley debate is published in Chemical & Engineering News
2004	First policy conference on advanced nanotech First center for nanomechanical systems
2010	DNA-based “robotic” assembly begins
2011	First programmable nanowire circuits for nanoprocessors DNA molecular robots learn to walk in any direction along a branched track Mechanical manipulation of silicon dimers on a silicon surface

While discussing the history of nanotechnology, it is important to highlight the contributions of some of the scientists involved, as follows.

1.2.1 Eric Drexler

Engineer Eric Drexler is known as the driving force behind the idea of molecular nanotechnology, having explored the subject in much greater depth than anyone before him, and he is thought of as the “founding father of nanotechnology” [3]. In 1986, he wrote the book, Engines of Creation: The Coming Era of Nanotechnology. In 1991, Drexler defended his MIT doctoral dissertation in molecular nanotechnology, Nanosystems: Molecular Machinery, Manufacturing, and Computation. Drexler established the field of molecular nanotechnology, and his work inspired scientists to explore bonds and molecules to further develop the manufacturing systems of nanotechnology. This has helped physicists and engineers scale down their macroscopic systems concepts to the molecular level.

1.2.2 Richard E. Smalley

Smalley was awarded the Nobel Prize in chemistry for the discovery of buckminsterfullerene in 1996. He was a professor of physics, chemistry and astronomy at Rice University in Texas. Founding director of their Center for Nanoscale Science and Technology from 1996 to 2002, Smalley then became director of Rice's new Carbon Nanotechnology Laboratory. He worked extensively with various kinds of fullerenes such as C60, C70, etc., and popularized their use in various conducting applications [4]. His research on elongated fullerenes popularized buckytubes, which were a new high-tech polymer, following on from nylon, polypropylene, and Kevlar. Compared to other conducting polymers known at that time, buckytubes were more conducting and found application in nearly every technology where electrons flow.

1.3 Classification of Nanomaterials

Nanotechnology's current state enables the manufacture of various nanostructured materials and the tailoring of their properties. Reduction in the spatial dimension, or confinement of particles or quasiparticles in a particular crystallographic direction within a structure generally leads to changes in physical properties of the system in that direction. In most cases, classification of the nanostructured materials and systems depends on the number of nanometer range dimensions.

1.3.1 Zero-Dimension Structures

Systems confined in three dimensions are considered to be zero-dimensional structures. They consist of particles of a few tens to a few hundreds of nanometers in size. Nanomaterials have a large surface-area-to-volume ratio, which gives them new, enhanced properties compared to their bulk properties [5]. The use of nanopowders in various matrices can create...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Chapter 1: Nanotechnology: The Science of the Invisible
• Chapter 2: An Overview of Metal Oxide Nanostructures
• Chapter 3: Quantum Nanostructures (QDs): An Overview
• Chapter 4: Heterostructured Nanomaterials: Latest Trends in Formation of Inorganic Heterostructures
• Chapter 5: Methods for Synthesis of Nanoparticles and Fabrication of Nanocomposites
• Chapter 6: Synthesis of Nanocomposites
• Chapter 7: Green Synthesis of Nanomaterials
• Chapter 8: Synthesis Strategies of Single-Phase and Composite Multiferroic Nanostructures
• Chapter 9: Silicon Carbide Nanomaterials
• Chapter 10: Recent Advances in the Synthesis of Metal Oxide (MO) Nanostructures
• Chapter 11: Hydrogels: Smart Nanomaterials for Biomedical Applications
• Index