Environmental Engineering Reference
In-Depth Information
table .
Methods for enironmental analyses of nanoparticles
technique
Parameters Measured
Resolution/sensitiity
limitations/adantages
enironmental applications
nanoparticle imaging
Electron.microscopy.(SEM,.
TEM,.ESEM)
Particle.size,.shape,.texture,.
crystalline.vs..amorphous.
structure,.elemental.
composition,.bonding.
1.nm.SEM,.<0.1.nm.TEM
Particle-by-particle.analysis,.time-
consuming..Sample.preparation,.
high.vacuum.for.SEM,.TEM.may.
alter.particles..ESEM.allows.
imaging.in.water.or.other.liquid.
media
Ambient.air.studies.[11],.
nanoparticle.characterization.
for.laboratory.studies.of.fate,.
toxicity.[7-10]
Scanning.probe.microscopy.
(STM,.AFM).
Particle.size,.morphology
0.5.nm
Particle-by-particle.analysis..
Analysis.at.ambient.pressure,.
particles.may.be.in.solution
Ambient.air.studies,.natural.
colloids.[15-17,.20,.21]
Compositional analysis
Single-particle.mass.
spectrometry
Chemical.composition,.organic.
and.inorganic.species
3.nm.particle
Continuous.analysis.of.particles.in.
air.stream
Atmospheric.studies,.vehicular.
emissions.[23,.24]
Particle-induced.x-ray.(PIXE)
Elemental.mapping.of.
nanoilms.or.collected.
nanoparticles
1.micron
Requires.radioactive.source.
Air.pollution.studies.[28]
surface area
BET
Average.surface.area.on.a.mass.
basis
2000.m
2
/g
Laboratory-based.instrument;.
requires.relatively.pure.bulk.sample.
of.chemically.homogenous.
material.
Characterization.for.laboratory.
studies.of.fate,.toxicity.[29]
Epiphaniometer
Active.surface.area
10-20.nm.particles,.0.003.
m
2
/cm
3
Requires.radioactive.lead.source
Ambient.air.studies.[30]
Aerosol.diffusion.charger
Aerosol.surface.area
10.to.100.nm.in.diameter.
Fast.response
Ambient.air.[31]
