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Nanomaterials, devices and technologies.



Nanostructured materials are those materials whose structural elements—clusters, crystallites or mol­ecules—have dimensions in the range of 1-100 nm. These small groups of atoms, in general, go by different names such as nanoparticles, nanocrystals, quantum dots and quantum boxes. Substantial work is being carried out in the domain of nanostructured materials and nanotubes during the past decade since they were found to have potential for high technology engineering applications. One finds a remarkable variations in fundamental electrical, optical and magnetic properties that occur as one progresses from an ‘infinitely extended’ solid to a particle of material consisting of a countable number of atoms. The various types of nanostructured materials which has been considered for applications in opto-electronic devices and quan­tum-optic devices are nano-sized powders of silicon, silicon-nitride (SiN), silicon-carbide (SiC) and their thin films. Some of these are also used as advanced ceramics with controlled micro structures because their strength and toughness increase when the grain size diminishes. Carbon-based nanomaterials and nanostructures including fullerenes and nanotube plays an increasingly pervasive role in nanoscale science and technology. Today, nanotechnology is being heralded as the next enabling technology that will redesign the future of several technologies, products and markets. A brief account of nanostructured materials, particularly of carbon based nanomaterials and nanostructures is presented in a separate chapter.

The interest in these materials has been stimulated by the fact that, owing to the small size of the building blocks (particle, grain, or phase) and high surface-to-volume ratio, these materials are expected to demonstrate unique mechanical, optical, electronic and magnetic properties.

These enhanced properties have been shown to be much more beneficial and valuable to mankind than conventional materials in the micron size range prompting many scientists and industry experts to predict that "nanotechnology initiatives (will) ... lead to the next industrial revolution having the same profound impact on economy and society as Information Technology and Bio-Technology."

The cost of nanomaterials produced using the proprietary HGRP technology platform is lower than that by other conventional technologies. This cost saving will help to lower the barrier and pave the road for broad application of nanomaterials into many industrial and consumer products.

Synthesis methods for new materials - Методы синтеза новых материалов

The properties of nanostructured depend on the following 4 common microstructural features:

• fine grain size and size distribution (< 100 nm);

• chemical composition of the constituent phases;

• presence of interfaces, more specifically, grain boundaries, hetero-phase interfaces, or the free surface;

• interactions between the constituent domains

The presence and interplay of these 4 features largely determine the unique properties of nanomaterials

New technology

Technology is a broad concept that deals with a species' usage and knowledge of tools and crafts, and how it affects a species' ability to control and adapt to its environment. Technology is a term with origins in the Greek "technologia", "τεχνολογία" — "techne", "τέχνη" ("craft") and "logia", "λογία" ("saying"). However, a strict definition is elusive; "technology" can refer to material objects of use to humanity, such as machines, hardware or utensils, but can also encompass broader themes, including systems, methods of organization, and techniques. The term can either be applied generally or to specific areas: examples include "construction technology", "medical technology", or "state-of-the-art technology".

The distinction between science, engineering and technology is not always clear. Science is the reasoned investigation or study of phenomena, aimed at discovering enduring principles among elements of the phenomenal world by employing formal techniques such as the scientific method. Technologies are not usually exclusively products of science, because they have to satisfy requirements such as utility, usability and safety.

Engineering is the goal-oriented process of designing and making tools and systems to exploit natural phenomena for practical human means, often (but not always) using results and techniques from science. The development of technology may draw upon many fields of knowledge, including scientific, engineering, mathematical, linguistic, and historical knowledge, to achieve some practical result.

Technology is often a consequence of science and engineering — although technology as a human activity precedes the two fields. For example, science might study the flow of electrons in electrical conductors, by using already-existing tools and knowledge. This new-found knowledge may then be used by engineers to create new tools and machines, such as semiconductors, computers, and other forms of advanced technology. In this sense, scientists and engineers may both be considered technologists; the three fields are often considered as one for the purposes of research and reference.

The exact relations between science and technology in particular have been debated by scientists, historians, and policymakers in the late 20th century, in part because the debate can inform the funding of basic and applied science. In immediate wake of World War II, for example, in the United States it was widely considered that technology was simply "applied science" and that to fund basic science was to reap technological results in due time. An articulation of this philosophy could be found explicitly in Vannevar Bush's treatise on postwar science policy, Science—The Endless Frontier: "New products, new industries, and more jobs require continuous additions to knowledge of the laws of nature... This essential new knowledge can be obtained only through basic scientific research." In the late-1960s, however, this view came under direct attack, leading towards initiatives to fund science for specific tasks (initiatives resisted by the scientific community). The issue remains contentious—though most analysts resist the model that technology simply is a result of scientific research.

Material Science broadly encompasses the fundamental study of solid matter with the goal of engineering new materials with superior properties, and ultimately enabling altogether new types of devices. Historically, materials science focussed on metallurgical and ceramic systems, and the state of technological achievement of ancient (European) societies has been described in terms of materials – the stone age, the bronze age and the iron age. In the modern era, Material Science makes use of advanced fabrication and characterization tools that allow us to observe and manipulate matter virtually atom by atom. The field is inherently interdisciplinary, with strong connections to physics, chemistry, biology and the engineering fields. Materials scientists tackle such problems as the discovery of efficient electrolytes and electrodes for batteries and fuel cells (for sustainable energy), the design of nanoscale structures that can use light for communication (photonics), and the fabrication of high strength metals free of traditional failure modes (bulk metallic glass). In each case, tackling such problems requires fundamental thermodynamic and kinetic insights to answer the question: why do materials behave the way they do?

 

 




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