Page 21 - Environmental Nanotechnology Applications and Impacts of Nanomaterials

Nanotechnology and the Environment 7

Figure 1.1 Elements of environmental risk assessment focusing on the use of nanomate-
rials in environmental technologies.

and risk management (Figure 1.1). Considerations in integrating this
information to arrive at a risk assessment for a given nanomaterial are
presented in Chapter 13.

Properties and principles of nanomaterials
Nanoscale particles have long been present in environmental systems and
play a significant role in the function of many natural processes. Examples
of naturally occurring nanoscale particles include those resulting from
mineral weathering (e.g., iron oxides and silicates) and emissions from
combustion processes (i.e., carbon soot). Recent advances in the area of
nanoscience have provided a means to characterize and manipulate nat-
urally occurring nanomaterials as well as to manufacture engineered
nanoparticles (e.g., metal oxides, carbon nanotubes, and buckminster-
fullerene). It is now possible to control the chemical and physical prop-
erties of nanoparticles and to tailor them for specific applications. In
Chapter 3, methods for fabricating nanomaterials and some of the unique
properties of these materials are presented. Methods for structural and
chemical characterization are presented in Chapter 4.