ABSTRACT
This chapter describes the nanoscience background and to delineate the very special problems posed to regulators, researchers and the public by emerging category of new materials. Nanomaterials are so tiny that ten thousand of them side by side would approximate to the thickness of a human hair. Zerovalent metals include iron (Fe), gold (Au) and silver (Ag), and can be made as nanoparticles by reduction or co-reduction of metal salts. Nanomaterials have properties that differ somewhat from those of corresponding bulk macromaterials of the same chemical nature. It is increasingly evident that indicators of toxicity depend strongly on the average particle diameter of nanomaterials. Dendrimers are highly branched spherical structures made up of building block monomers which consist of a core, a branching network and a chemically functionalised surface. Carbon is largely a chemically unreactive material at the macroscale where it occurs as stable allotropes in one of the hardest known substances and one of the softest known substances.
