ABSTRACT
Much of this book focuses on nanomaterials as a new, and to some extent, unknown class of materials. Physicists, chemists, and material scientists working with entrepreneurs are designing engineered nanoparticles with novel characteristics and properties appropriate to their application including paints, coatings, structural constituents, to nanomedicines. This chapter emphasizes the reality that although many nanomaterials are novel-such as fullerenes, graphene, carbon nanotubes, and nanomedicines-others are familiar and have existed for millennia. In general, these particles, which we will call unintentional particles, are the smallest particles in a distribution of polydisperse particles produced through combustion or as a consequence of evaporation and condensation of volatized materials such as metals, organic compounds, or even sea water.
