C hapTer 11 nanomaterials and nanotechnologies
486
commonly used substances, such as activated charcoal. The following sections explore some of these applications in greater detail.
environmental Monitoring
The use of networked monitoring devices—largely sensors of one
type or another—is critical to understanding the kinds, magnitudes,
and distributions of environmental pollutants that are present
in our air, water, and earth environments. Without these understandings, remediation and treatment efforts may be sporadic or
misplaced. Needs are present at the broad scale of the environment and at the very narrow scale of measurements in relation
to specific manufacturing processes for control purposes. Many
nanomaterials can excel for these needs. As previously discussed
in Section 11.3, nano-based biosensors of one type or another can
be designed to detect many kinds of biological or chemical substances. Many approaches are possible, depending on the need.
Nanomaterials with catalytic properties can not only act as remediators but also as sensors. Chemical sensors based on nanotubes
and nanowires have also been demonstrated. Properties used are
often unique to nanomaterials. Measurable electrical resistance
changes in nanotubes exposed to different chemicals, for example,
can be used as the technical basis for detectors of this type. Many
other approaches exist.
Nanotechnologies in the form of NEMS devices are under development to serve not only as sensors and monitors but as analyzers and
communication devices as well. These are quite similar to “lab-ona-chip” approaches discussed earlier. Tiny channels can be made to
store and transport various gases or fluids through various parts of
the device so that specific analyses can be made. The potential to
make such devices small can allow their use in many situations not
possible before.
Water Cleaning and purification
Considerable excitement surrounds the potential of nanomaterials in the remediation of many environmental problems that affect
our society. Many kinds of needs for environmental remediation
technologies exist, but two—air and water purification—stand out
as particularly important. Improvements in these areas would help
alleviate many of the pressing health problems facing large population segments throughout the world. Adverse effects associated
with pollutants in both water and environments are widely under-
486
commonly used substances, such as activated charcoal. The following sections explore some of these applications in greater detail.
environmental Monitoring
The use of networked monitoring devices—largely sensors of one
type or another—is critical to understanding the kinds, magnitudes,
and distributions of environmental pollutants that are present
in our air, water, and earth environments. Without these understandings, remediation and treatment efforts may be sporadic or
misplaced. Needs are present at the broad scale of the environment and at the very narrow scale of measurements in relation
to specific manufacturing processes for control purposes. Many
nanomaterials can excel for these needs. As previously discussed
in Section 11.3, nano-based biosensors of one type or another can
be designed to detect many kinds of biological or chemical substances. Many approaches are possible, depending on the need.
Nanomaterials with catalytic properties can not only act as remediators but also as sensors. Chemical sensors based on nanotubes
and nanowires have also been demonstrated. Properties used are
often unique to nanomaterials. Measurable electrical resistance
changes in nanotubes exposed to different chemicals, for example,
can be used as the technical basis for detectors of this type. Many
other approaches exist.
Nanotechnologies in the form of NEMS devices are under development to serve not only as sensors and monitors but as analyzers and
communication devices as well. These are quite similar to “lab-ona-chip” approaches discussed earlier. Tiny channels can be made to
store and transport various gases or fluids through various parts of
the device so that specific analyses can be made. The potential to
make such devices small can allow their use in many situations not
possible before.
Water Cleaning and purification
Considerable excitement surrounds the potential of nanomaterials in the remediation of many environmental problems that affect
our society. Many kinds of needs for environmental remediation
technologies exist, but two—air and water purification—stand out
as particularly important. Improvements in these areas would help
alleviate many of the pressing health problems facing large population segments throughout the world. Adverse effects associated
with pollutants in both water and environments are widely under-