Application of Radiation in Nanotechnology

The Nanotechnology is one of the fastest growing new areas in science and engineering. The subject arises from the convergence of electronics, physics, chemistry, biology and materials science to create new functional systems of nano-scale dimensions. Nanotechnology deals with science and technology associated with dimensions in the range of 0.1 to 100 nm. The ability to fabricate structures with nano-metric precision is of fundamental importance to any exploitation of nanotechnology. Nanotechnology is predicted to have a major impact on the manufacturing technology in 20 to 30 years from now. The ability to fabricate structures with nano-metric precision is of fundamental importance to any exploitation of nanotechnology. The potential of combining radiation effects with nano-materials has been recognized from the very early stages of nano-science research. In the many uses of nano- structures, and nano-particles in particular, from catalysis, bio-sensing, nano-electronics, magnetic applications including separations, mechano-chemical conversion, and to molecular computing, radiation can play a significant role. The use of radiation, UV beam, electron-beam, or focused ion-beam is clearly central to the fabrication of the nanostructured systems. The relative advantages and deficiencies of each of them are still to be clarified as the technology advances. Whether UV or electron beam will lead to the highest resolution is still debated but it is clear that these techniques offer unmatched reproducibility and very narrow size distribution. Other studies concern formation and synthesis of nano-particles and nano-composites. Radiation synthesis of copper, silver and other metals' nanoparticles is studied. Metal and salt-polymer composites are synthesized by this method. Metal sulphide semiconductors of nano-metric matrices are prepared using gamma irradiation of a suitable solution of monomer, sulphur and metal sources. These products find application in photoluminescent, photoelectric and non-linear optic materials. An interesting field of radiation nano-technological application concerns the development of PC-controlled bio-chips for programmed release systems. Nano-ordered hydrogels based on natural polymers as polysaccharides (hyaluronic acid, agarose, starch, chitosan) and proteins (keratin, soy-bean) being pH and electric potential responsive materials for such bio-chips and sensors. To avoid the regress in further developments concerning radiation processing of natural polymers, the nano approach to these biological materials should be developed further. The studies on natural rubber-clay composites and thermoplastic natural rubber-clay composites have given interesting results. (Author)