ABSTRACT
Nanotechnology has emerged as a quite interdisciplinary field of modern science and technology. Nanomaterials have found a wide range of different applications in many aspects of human life. What makes nanomaterials interesting for fundamental and applied research is their small size (usually less than 100 nm), which is the reason for their remarkable physical and chemical properties, different from those of their larger counterparts of the same chemical composition. Nanoparticles have a large fraction of their atoms on the surface, which is among the reasons for their unique physicochemical characteristics, high surface energy and tendency for aggregation. Nanoparticles prepared by wet chemical methods are usually coated with a capping layer of organic molecules, which prevents aggregation and determines their surface chemistry, zeta potential, hydrophilicity/hydrophobicity, stability (stabilization via electrostatic or steric repulsion between nanoparticles), and surface functionalities. The unique characteristics of nanomaterials include specific electromagnetic, optical, catalytic, mechanical, thermal, pharmacokinetic, and targeting properties, which make them attractive for commercial, technological, and therapeutic applications (Edelstein and Cammaratra 1998). Currently, the list of consumer goods in the nano-field is constantly increasing, involving many different products containing
2.1 Introduction .................................................................................................... 37 2.2 Nanomaterials as Environmental Hazards ..................................................... 39
2.2.1 Manufactured Nanomaterials and Nanowastes .................................. 39 2.2.2 Carbon Nanostructures .......................................................................40 2.2.3 Oxide Nanoparticles ........................................................................... 42 2.2.4 Metal Nanoparticles ............................................................................44 2.2.5 Semiconductor Nanoparticles ............................................................. 45
2.3 Fate of Disposed Nanomaterials in Ecosystems .............................................46 2.4 Management of Nanowastes ...........................................................................48 2.5 Conclusions .....................................................................................................50 Acknowledgments ....................................................................................................50 References ................................................................................................................50
