ABSTRACT
Nanotechnology makes use of materials whose structures have characteristic features on the nanoscale (i.e., on the scale of 10−9 meter [a nanometer, nm]). Obviously, this size is a very small one compared to objects we have around ourselves, but it is not particularly small on an atomic scale [1]. Indeed, characteristic distances between atoms in a solid are of the order of 10−10 meter (a tenth of a nanometer, also called an Ångström), so a piece of material whose side is one nm may contain hundreds or up to a thousand atoms. This means that, normally, a nanomaterial shows some resemblance to a normal solid comprising the same atoms, but it is typically modied to achieve some superior property such as higher strength, different electromagnetic properties, permeability to a uid, or some other quality. A higher strength may mean that less material is needed to accomplish a given task; different electromagnetic properties may mean that we can harness the sun’s rays more efciently in a solar energy conversion device or that we can build better electrical generators, and achieving a desired permeability may lead to improved ltering technology to remove undesired substances from water or air. Of course, these examples can be multiplied almost ad innitum. Figure 1.1 illustrates the size of various things and sets “nano” in the proper perspective.
