Environmental Applications and Implications of Nanotechnology and Nanomaterials

Abstract

There exists many similar definitions for nanotechnology in various dictionaries and literature sources like ‘‘any technology on the scale of nanometers’’ ~Infoplease Dictionary!, ‘‘the art of manipulating materials on a very small scale in order to build microscopy machinery’’ ~Encarta World English Dictionary, North American Edition!, ‘‘the branch of engineering that deals with things smaller than 100 nanometers ~especially with the manipulation of individual molecules’’ ~Rhymezone!, and ‘‘the science and technology of building electronic circuits and devices from single atoms and molecules’’ ~The American Heritage Dictionary of the English Language: Fourth Edition, 2000!. In all these definitions, the term nanotechnology is currently associated mainly with length in the nanometer scale ~1 nm is one billionth of a meter, 1 nm510 m), rather than any other physical property ~i.e., mass, volume!. In order to differentiate it from the term micro electro mechanical systems ~MEMS!, which are usually of larger dimensions, nanotechnology is also known with the term molecular nanotechnology. Although the concept of nanotechnology was first introduced in 1959 by Richard Feynman in his presentation ‘‘There’s plenty of room at the bottom’’ ~http:// www.zyvex.com/nanotech/feynman.html!, it was Erick K. Drexler in his 1986 book The Engines of Creation: The Coming Era of Nanotechnology who introduced nanotechnology as a new paradigm for manipulating atoms and molecules in the atomic level to produce desirable substances or molecular-sized machines ~i.e., nanomachines!. Shortly after Feynman and Drexler’s conceptualization of orchestrating matter at the atomic and molecular level to produce useful nanoassemblies, nanodevices, and nanomaterials, the concept was applied in several studies of nanofabrication. While many disciplines in science and engineering have being applying and studying for several decades various aspects that are certainly incorporated in the term nanotechnology ~i.e., preparation and application of nanofiltration and reverse osmosis membranes, preparation and application of catalytic materials and adsorbents including zeolites, synthesis and applications of novel chemical structures, formation and fate of aerosol particles, and formation of particle aggregates in coagulation!, it was not until recently that nanotechnology has evolved into a new paradigm of technological innovation and opened new horizons of extreme engineering on the nanometer scale. During the last 5 years, nanotechnology has revolutionized the way we could do things, either in terrestrial or space applications, and developed into a new discipline of significant technological, economic, social, political, and cultural importance, both nationally and internationally. In the aurora of the anticipated era of nanotechnology, along ith many other nanotechnological inventions and breakthroughs