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B
Poster Abstracts
MEASUREMENTS OF NEUTRAL NUCLEATING octopole device in the first vacuum stage for transmitting
MOLECULAR CLUSTERS IN THE ATMOSPHERE and focusing ions, which was further confirmed by ion
trajectory simulations using SIMION. The Cluster-CIMS
J. Zhao,1 F. L. Eisele,1 J. N. Smith,1,2 M. Chen,3 J. Jiang,3
was well calibrated with an electrospray coupled to a high-
M. Titcombe,3 C. Kuang,4 and P. H. McMurry3
resolution differential mobility analyzer (ES-HDMA). The
1Atmospheric Chemistry Division, National Center for
calibration showed that the Cluster-CIMS has a relatively
Atmospheric Research, Boulder, CO 80301
flat sensitivity in the mass range of 190-400 amu, covering
2Department of Physics and Mathematics, University of
the masses of sulfuric acid clusters containing 2-4 H2SO4.
Eastern Finland, P.O. Box 70211 Kuopio, Finland
The ion cluster formation in the atmospheric-pressure inlet
3University of Minnesota, Department of Mechanical
was controlled by two processes: neutral ionization and ion-
Engineering, Minneapolis, MN 55455
induced clustering (IIC), which can be differentiated from
4 Department of Atmospheric Science, Brookhaven
the time independency of the intensity ratio between the
National Laboratory, Upton, NY 11973-5000
cluster and monomer ions. Two methods were employed to
separate neutral clusters from the ion-induced clustering. The
Atmospheric nanoparticles produced by nucleation can
concentrations and distribution of the neutral nucleating clus-
subsequently grow to cloud condensation nuclei (CCN)
ters containing up to 4 H2SO4 are estimated from the above
within one or two days and hence affect cloud formation,
methods at three measurement sites (NCAR foothill labora-
precipitation, and atmospheric radiation budgets. As an
tory, Manitou Forest Observatory, and Atlanta). Typically,
intermediate stage between molecules and nanoparticles,
the molecular cluster concentrations are well correlated with
neutral molecular clusters are believed to play an important
the concentrations of nanoparticles measured simultaneously
role in processes that lead to boundary layer nucleation.
during the nucleation event periods. The Cluster-CIMS was
Therefore, knowledge of chemical composition, concentra-
employed to measure clusters containing both sulfuric acid
tions, thermodynamic properties, and evolution of neutral
and amines in summer 2010 at NCAR foothill laboratory.
molecular clusters is essential to better elucidate the nucle-
Correlation between these clusters and nanoparticles mea-
ation mechanism and to reduce the uncertainty in nucleation
sured by several particle counters will be presented.
rates used in global climate models.
Here we present field measurements from a recently Zhao, J., F. L. Eisele, M. Titcombe, C. Kuang and P. H. McMurry. 2010.
d eveloped chemical ionization mass spectrometer (the Chemical ionization mass spectrometric measurements of atmospheric
Cluster-CIMS) designed to measure atmospheric neutral neutral clusters using the Cluster CIMS. Journal of Geophysical
Research 115, D08205, doi:10.1029/2009JD012606.
clusters (Zhao et al., 2010). The sensitivity of the Cluster-
CIMS was significantly improved by using a unique conical
63
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64 APPENDIX B
IN SITU STUDIES OF EQUILIBRIUM AND
EXPLORING PARTICLES FROM THE NANO- TO
NON-EQUILIBRIUM SMALL-PARTICLE DYNAMICS
MICROSCALES ELECTRON MICROSCOPIC ANALYSES
OVER EXTENDED LENGTH AND TIME SCALES USING
ON ENGINEERED AND INCIDENTAL NANOPARTICLES
ULTRASMALL-ANGLE X-RAY SCATTERING/X-RAY
IN BIOSOLID PRODUCTS
PHOTON CORRELATION SPECTROSCOPY
B. Kim,1 C.-S. Park,2 M. Murayama,2,3 and M. F. Hochella,
(USAXS/XPCS)
Jr.1,3
J. Allen,1 F. Zhang,1 L. E. Levine,1 J. Ilavsky,2 A. R. Sandy,2
1The Center for NanoBioEarth, Department of Geosci -
and G. G. Long1,2
ences, Virginia Tech, Blacksburg, VA 24061
1Material Measurement Lab., NIST, Gaithersburg, MD.
2Department of Materials Science and Engineering, Vir-
Email: Andrew.allen@nist.gov
ginia Tech, Blacksburg, VA 24061
2 X-ray Science Div., APS, Argonne National Lab.,
3Institute for Critical Technology and Applied Science,
Argonne, IL. Email: ilavsky@aps.anl.gov
Virginia Tech, Blacksburg, VA 24061
Both scattering and imaging techniques successfully
With the dramatic growth of nanotechnology, the pro-
characterize the microstructures of advanced materials,
duction and use of engineered nanoparticles has been
including small particle systems and suspensions. Yet the
r apidly increasing for the past few years. Engineered
dynamics of these materials, especially responses to abrupt
nanoparticles that are produced and/or incorporated into
changes in environment, largely remain elusive. X-ray pho-
consumer products will enter the environment after and/or
ton correlation spectroscopy (XPCS) has emerged as a tech-
during the term of use, which in turn has raised concerns
nique offering unprecedented sensitivity to equilibrium and
about their potentially adverse impact on the environment.
nonequilibrium dynamics within material systems, including
However, there has been little success with identifying nano-
small particles. However, existing XPCS facilities are limited
sized engineered and incidental particles from complex het-
to microstructure length scales smaller than 50 nanometers,
erogeneous environmental samples, limiting our understand-
eliminating large classes of materials of technological impor-
ing of their environmental fate and influence. Lack of such
tance. Recently, we have developed combined ultrasmall-
studies is in part due to technical challenges in discovering
angle x-ray scattering/x-ray photon correlation spectroscopy
and monitoring the environmental occurrence of engineered
(USAXS/XPCS) to probe the slow equilibrium and nonequi-
and incidental nanoparticles present at trace levels. In order
librium dynamics of optically opaque materials with features
to overcome this problem, we looked at a “bottleneck” for
in a size range from 100 nm to several micrometers, i.e.,
engineered nanoparticles in the form of a large metropolitan
between those of dynamical light scattering and conven-
wastewater treatment facility. There, nanoparticles from con-
tional XPCS. Two examples illustrate the in situ capability
sumer products may concentrate especially at the end stage
of USAXS-XPCS: the equilibrium dynamics of colloidal
of treatment processes where biosolids (sludges) are gener-
particle dispersions at various volume concentrations as a
ated. We looked for the presence of nanosized particles in this
function of temperature; and the nonequilibrium dynamics
complex organic material using analytical high-resolution
of the small particle configuration within a polymer com-
transmission electron microscopy. We found nanoparticulate
posite, for which USAXS/XPCS reveals incipient dynamical
silver sulfides, presumably derived from silver nanoparticles
changes not observable by other techniques.
and/or ionic Ag that were reacting with reduced S species in
the sedimentation processes during wastewater treatment, as
well as a variety of titanium oxide nanoparticles. For both
materials, their size, morphology, elemental compositions,
and degree of crystallinity and aggregation state were studied
in detail. The results of our work clearly show a great degree
of nanoparticle heterogeneity and complexity in biosolid
products. We believe that this study will help us evaluate fur-
ther risks when nanoparticle-bearing biosolid products enter
the soil environment through agricultural land applications.
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65
APPENDIX B
CHARACTERIZATION OF MICRO-PARTICLE ADHESION IMAGING SMALL PARTICLES IN CELLS USING SOFT
IN PHARMACEUTICAL ENGINEERING X-RAY TOMOGRAPHY
N. Zarate,1 D. Balachandran,1 J. Litster,1 and S. Beaudoin1 M. Uchida,1,3 E. Hanssen,2 C. Knoechel,1,3 G. McDermott,1,3
M. Le Gros,3,4 L. Tilley,5 and C. Larabell13,4
1School of Chemical Engineering, Purdue University,
1Department of Anatomy, University of California San
West Lafayette, IN 47906
Francisco, San Francisco, CA 94143, USA
2Electron Microscopy Unit Bio21, Molecular Science
The understanding of interaction forces that arise when
particles and surfaces come into close contact continues to and Biotechnology Institute, University of Melbourne, Mel-
be a significant focus of research. It can benefit many areas bourne, VIC 3010, Australia
3National Center for X-ray Tomography, Lawrence Berke-
of study particularly in the pharmaceutical, chemical, and
mineral industries involving solid processing. The work ley Laboratory, Berkeley, CA 94720, USA
4 Physical Biosciences Division, Lawrence Berkeley
presented investigates capillary condensation effect on adhe-
sion forces between particles and surfaces as it is exposed to National Laboratory, Berkeley, CA 94720, USA
5Department of Biochemistry and Center of Excellence
different levels of relative humidity. Direct force measure-
ments between molecularly smooth surfaces seem to match for Coherent X-ray Science, La Trobe University, Melbourne,
accurately with conventional models, but with real particles VIC 3086, Australia
and surfaces the forces display extreme discrepancies due
to their natural heterogeneity such as roughness and uneven Soft x-ray tomography (SXT) is a new tool for imaging
liquid condensate layers. whole, hydrated biological specimens up to 15 microns thick
The investigations on the microscale interactions are with a spatial resolution better than 50 nm. In SXT, cells
developed for nonideal surfaces to give more significant are imaged using photons between the K shell absorption
edges of carbon (284 eV, λ = 4.4 nm) and oxygen (543 eV,
insight on the macroscale than ideal surfaces. The results
λ = 2.3 nm). These photons readily penetrate the aqueous
have confirmed liquid condensation is present on the surface
area of tooling surface on the microscale through a phase environment while encountering significant absorption from
imaging technique. This was the first time it was applied carbon- and nitrogen-containing organic material. In this
in the context of pharmaceutical manufacturing, which energy range, referred to as the “water window,” organic
can facilitate the design of surfaces during processing. The material absorbs approximately an order of magnitude more
traditional approach for designing processing and particle strongly than water, producing quantitative, high-contrast
interactions heavily relied on the behavior of large amounts images of intact, fully hydrated cells without the need to
of particles and indirect measurements of the adhesion forces use contrast-enhancing agents. The high penetrating power,
of the surface. The understanding of the interactions between coupled with a near absence of reflection at the interface of
single particles and tooling surfaces can provide useful dissimilar materials, makes x-rays an ideal probe for study-
information through several characterization techniques ing cellular morphology. These unique imaging properties
such as atom force microscopy (AFM) and scanning electron also make x-ray a powerful tool for determining the precise
microscopy (SEM). position of small particles with respect to cellular structures.
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66 APPENDIX B
CHARACTERIZING MOLECULAR CONJUGATION AND CHEMICAL IMAGING ACTIVITIES ASSOCIATED WITH
AGGREGATION OF NANOSCALE PARTICLES USING NANOPARTICLES AT PACIFIC NORTHWEST NATIONAL
COMPLEMENTARY PHYSICAL MEASUREMENT LABORATORY
METHODS
S. Thevuthasan,1 L. Terminello,1 and E Hui1
Tsai,1 Cho,1 DelRio,1 MacCuspie,1 1Pacific Northwest National Laboratory, Richland, WA
D.-H. T.-J. F. R. I. M. R.
Zachariah,1,2 and V. A. Hackley1 99354, Theva@pnl.gov
1Materials Measurement Laboratory, National Institute of
Chemical analysis and identification through direct imag-
Standards and Technology, Gaithersburg, MD 20899
2Departments of Mechanical Engineering & Chemistry, ing is a powerful means to develop an atomistic understand-
ing of scientific issues associated with knowledge gaps and
University of Maryland, College Park, MD 20742
problems in energy, environment, and national security.
We present results based on complementary physical For example, identification of mechanisms associated with
c haracterization methods performed under both fluid- transformations requires the direct observation of the reac-
based and aerosolized conditions in order to interrogate the tions to develop the atom-by-atom model of the structural
molecular conjugation and colloidal stability of nanoscale and chemical changes. Recently we introduced a laboratory-
particles. From the change in hydrodynamic and aerosol par- wide chemical imaging initiative to develop the suite of tools
ticle size, we can probe the formation of molecular coatings needed for such a transformation. Central to this initiative
and particle aggregates. For the purpose of characterizing will be development of an in situ tool suite with nanometer
nanoscale gold-based platforms for cancer therapeutics, resolution and element specificity that will allow researchers
citrate-stabilized gold nanoparticles (Au-NPs) conjugated by to couple the molecular-level chemical and structural infor-
thiolated polyethylene glycol (SH-PEG) are used as a model mation to large-scale scientific challenges. In particular, we
system. Dynamic light scattering and asymmetric-flow field will develop (a) synchrotron light-source-based capabilities
flow fractionation are used to characterize particle popula- coupled with laboratory-based imaging capabilities for three-
tions under relevant fluid conditions. For comparison, atomic dimensional tomographic, structural, and element-specific
force microscopy and electrospray differential mobility interrogation at the molecular level, (b) coupled optical,
analysis offer static imaging and dry aerosol characteriza- electron, ion, mass, and scanning probe microscopies to
tion, respectively. Combining information derived from these understand chemical, material, and biological transforma-
physical-based methods, we can then analyze the molecular tions and mechanisms, and (c) integrative hardware and soft-
conformation of SH-PEG on the Au-NP surface, calculate ware applications for real-time image reconstruction, feature
the surface coverage of SH-PEG, and estimate the degree extraction, and information integration. Brief descriptions
of aggregation and shelf life of Au-NP based products in of these activities will be presented along with the detailed
dispersed form. descriptions of two to three projects related to nanoparticle
characterization.
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67
APPENDIX B
IMPORTANCE OF SYNERGISM IN ATMOSPHERIC HARD SHELL GAS-FILLED CONTRAST
SECONDARY ORGANIC AEROSOL FORMATION: ENHANCEMENT PARTICLES FOR COLOR DOPPLER
CASE STUDY OF a-PINENE OXIDATION BY NO3 ULTRASOUND IMAGING OF TUMORS
RADICALS
H. P. Martinez,1 Y. Kono,2 S. L. Blair,3 R. F. Mattrey,2 A. C.
Perraud,1 Bruns,1 Ezell,1 Johnson,1 Kummel,1 and W. C. Trogler1
V. E. A. M. J. S. N.
Y. Yu,2 M. L. Alexander,3 A. Zelenyuk,3 D. Imre,4 and B. J. 1University of California San Diego, 9500 Gilman Dr.,
Finlayson-Pitts1 La Jolla, CA 92093-0358; martinez@ucsd.edu,wtrogler@
1Department of Chemistry, University of California, ucsd.edu
2University of California San Diego, Medical Center,
Irvine, CA 92697
2Currently at California Air Resources Board, 9528 Tel- Dickson St., San Diego, CA 92103
3University of California San Diego, Moores Cancer
star Avenue, El Monte, CA 91731
3Pacific Northwest National Laboratory, P.O. Box 999, Center, 3855 Health Sciences Dr., La Jolla, CA 92093
Richland, WA 99352
4Irme Consulting, 181 McIntosh Ct., Richland, WA 99352 Hollow hard shell particles of 200 nm and 2 micron
diameter with a 10-nm-thick porous silica shell have been
Secondary organic aerosols (SOAs) formed from the gas- synthesized using polystyrene templates and a sol-gel pro-
phase oxidation of volatile organic compounds (VOCs) are a cess. The template insures than the hollow particles are
major component of atmospheric particles. Biogenic VOCs monodispersed, while the charged silica surface insures that
have been long known as SOA sources via oxidation by O3, they remain suspended in solution for weeks. When filled
OH radicals, and NO3 radicals. While these reactions are with perfluorocarbon gas, the particles behave as an effi-
usually studied separately in laboratory controlled experi- cient contrast agent for color Doppler ultrasound imaging in
ments, in the atmosphere, reaction of VOC with one specific human breast tissue. The silica shell provides unique proper-
oxidant rarely occur in isolation. We report here the oxidation ties compared to conventional soft shell particles employed
of a-pinene, a well-documented biogenic emission, by NO3 as ultrasound contrast agents: uniform size control, strong
radicals with varying contributions from the O3 reaction, adsorption to tissue and cells immobilizing particles at the
where the O3 + NO2 reaction is the source of NO3 radicals. tissue injection site, a long imaging lifetime, and a silica
Experiments were carried out in air using a newly developed surface that can be easily modified with biotargeting ligands
large stainless steel flow tube. Particle concentration and or small molecules to adjust the surface charge and polarity.
chemical composition were measured simultaneously using
scanning mobility and aerodynamic particle sizers, two
aerosol mass spectrometers, and two integrative sampling
techniques (impaction on either ZnSe discs with subsequent
analysis by Fourier transform infrared spectroscopy or on
quartz-fiber filters followed by liquid chromatography with
UV-vis detection). Even small contributions by the ozone
chemistry had significant impacts on particle formation and
growth, as well as on composition. The synergism between
O3 and NO3 chemistry is discussed.
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68 APPENDIX B
CARDIOVASCULAR HEALTH EFFECTS OF PM2.5 AND EFFICIENT CHARACTERIZATION OF NANOPARTICLES
NICKEL NANOPARTICLE THROUGH AN INTELLIGENT COMBINATION OF
ANALYTICAL TECHNIQUES
E. N. Liberda,1 A. J. Madrid,1 Q. Qu,1 and L. C. Chen1
S. V. N. T. Kuchibhatla,1 S. Thevuthasan,1 A. S. Karakoti1,2
1New York University, Department of Environmental
P. Adusumilli,2 T. Prosa,3 R. Ulfig,3 V. Shutthanandan,1
Medicine, School of Medicine; eric.liberda@nyumc.org
C. M. Wang,1 P. Yang,1 and S. Seal4
1EMSL, Pacific Northwest National Laboratory, Richland,
It is well documented that exposure to ambient fine
p articulate matter (PM2.5) creates increased risks for WA 99354
2Northwestern University, Evanston, IL 60208
cardiovascular disorders (CVD) in humans. However, the
3Cameca Instruments Inc., Madison, WI 53711
mechanism(s) and component(s) responsible for PM2.5-
4 NSTC and AMPAC, University of Central Florida,
associated CVD are not known. Our recent animal studies
suggest that nickel (Ni) plays critical roles in PM2.5- Orlando, FL 32826; Satya@pnl.gov
associated CVD. To test this hypothesis, we identified two
areas, Jinchange and Zhangye, in China with comparable “There is plenty of room at the bottom”—the visionary
PM2.5 but different Ni exposures for which to investigate a statement of the legendary Feynman has been realized within
variety of cardiovascular markers including reparative endo- a decade by the researchers across the globe. The advent
thelial progenitor cells (EPCs). Ambient PM2.5 with high Ni of “nanoparticles” and the realization of their potential
content induced elevated systemic inflammatory markers and applications in defense, energy, environment and health
reduced EPCs. Additionally, we have shown that both low made the need for their synthesis and characterization quite
and high concentrations of inhaled Ni nanoparticles cause essential. However, the inherently complex nature of vari-
reduced numbers of bone marrow EPCs of mice as well as ous nanoparticles made their detailed characterization sig-
reduced functions of these cells and may be a mechanism by nificantly intricate. Here we present two specific examples:
which CVDs occur. Taken together, the results of the mouse (1) nanoparticles embedded in a matrix and (2) functional-
exposure bolster the findings from the human study and point ized nanoparticles. The efforts by the team of scientists from
toward a common cardiovascular maintenance cell popula- EMSL, to utilize the combination of high-resolution analyti-
tion that may be adversely affected by Ni on or in PM2.5. cal electron microscopy and laser-assisted 3D-atom probe
tomography for the three-dimensional chemical imaging of
embedded Au-nanoparticles in MgO single crystal, will be
presented. Also, in order to understand the functionalized
cerium oxide (ceria) nanoparticles, we are using a com-
bination of experimental, surface analysis using electron
and optical spectroscopies, and theoretical analysis of the
materials system. Nonlinear optical spectroscopy techniques
such as SHG, SFG along with XPS, TEM, UV-Vis, and
atomistic modeling are being utilized to obtain a molecular-
scale visualization of the functional group conformation
on the nanoparticles, surface chemistry, and its influence on
the functionality of the nanoparticles.
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69
APPENDIX B
SIZE DISTRIBUTION MEASUREMENTS OF NEWLY NEW PARTICLE FORMATION FROM
FORMED 1-6 NANOMETER ATMOSPHERIC METHANESULFONIC ACID IN AIR
AEROSOLS
M. L. Dawson,1 V. Perraud,1 M. J. Ezell,1 L. M. Wingen,1
Kuang,1 McMurry,2 Wang3 and B. J. Finlayson-Pitts1
C. P. and J.
1Atmospheric 1Department of Chemistry, University of California,
Science Division, Brookhaven National
Laboratory, Building 815E, Upton, NY 11973; ckuang@ Irvine, CA 92697-2025
bnl.gov
2Department of Mechanical Engineering, University of Identifying precursors and determining rates of formation
for new particles in the atmosphere is an essential step in
Minnesota, 111 Church St. SE, Minneapolis, MN 55455;
quantifying the effects of particulate matter on human health
mcmurry@me.umn.edu
3Atmospheric Science Division, Brookhaven National and climate change. Sulfuric acid is well known to play an
important role in new particle formation, and much work has
Laboratory, Building 815E, Upton, NY 11973; jian@bnl.gov
been done to characterize its role as a particle precursor, with
Atmospheric aerosols influence climate and climate recent studies suggesting the involvement of both ammonia
change on local to global scales by affecting the atmospheric and organic amines. Methanesulfonic acid (MSA) is wide-
radiation balance directly by scattering and absorbing incom- spread in the atmosphere as is formed alongside sulfuric acid
ing solar radiation and indirectly as cloud condensation in the oxidation of organosulfur compounds such as dimethyl
nuclei. New particle formation (NPF) by photochemical sulfide and methyl mercaptan. However much less is known
reactions of gas-phase precursors greatly increases the num- about its impact on new particle formation. We report here
ber concentrations of atmospheric aerosols, and therefore preliminary results from laboratory studies of new particle
their impact on climate. Although methods for measuring formation and growth from the gas phase reaction of MSA
sizes and concentrations N of newly formed particles of with organic amines. These studies are performed using a
diameter greater than 3 nm are well established, measure- unique flow tube system equipped with an electrical aerosol
ments of nanoparticles and neutral molecular clusters smaller analyzer and an scanning mobility particle sizer (SMPS),
than this are needed to constrain nucleation rates and to better which are used to measure particle size distributions as a
understand nucleation mechanisms. A new instrument for function of time and reactant concentration at 295 K in 1 atm
“bridging the gap” in measurements from neutral molecu- of air. The implications for the role of MSA in new particle
lar clusters to nanoparticles has been developed and was formation and growth will be discussed.
continuously deployed in an intensive measurement cam-
paign at Boulder, CO, in September 2010. Size distribution
measurements down to 1 nm are achieved with an electrical
mobility spectrometer using diethylene glycol as working
fluid (50% activation efficiency at 1.2 nm). Under conditions
of rapid NPF, N (Dp 5 nm) by
more than 100 fold, greatly influencing the dynamics of the
evolving aerosol.
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70 APPENDIX B
INHALED NICKEL NANOPARTICLES ENHANCES PHYSICOCHEMICAL PROPERTY MEASUREMENTS:
PROGRESSION OF ATHEROSCLEROSIS, REDUCES KEY TO ENABLING RISK AND FATE ASSESSMENT
VASCULAR REACTIVITY, AND ALTERS GENE FOR ENGINEERED NANOMATERIALS
ACTIVITY IN BRAIN IN A MURINE MODEL
T.-J. Cho,1 J. S. Taurozzi,1 D.-H. Tsai,1 R. I. McCuspie,1 A. J.
Cuevas,1 Liberda,1 Gillespie,1 Kang,1 Allen,1 and V. A. Hackley1
A. K. E. N. P. A. G.
and L.-C. Chen1 1National Institute of Standards and Technology, Nano-
1Department of Environmental Medicine, New York Uni- particle Measurements and Standards Project, Gaithersburg,
versity School of Medicine, 57 Old Forge Road, Tuxedo, MD 20899
NY 10987; amj316@nyu.edu, eric.liberda@nyumc.edu,
The National Institute of Standards and Technology is
gillespie.patricia@gmail.com, gsk227@nyu.edu, lung-chi.
actively working to address the need for physicochemical
chen@nyumc.org
property measurements applicable to engineered nano-
There is evidence that once deposition of inhaled nano- materials (ENMs) by developing, standardizing, and vali-
particles (NPs) occurs, the particles can bypass clearance dating transferable measurement methods, protocols, and
mechanisms and target secondary organs, such as, the cardio- certified reference materials. Another important component
vascular system and the brain. Utilizing a whole-body expo- of this effort is the interrogation of structure-property rela-
sure system, ApoE-/- or C57BL/6 male mice were exposed to tionships derived from critically evaluated experimental
either nickel hydroxide NPs (NHNP; 100, 150, or 900 µg/m3) results. Research activities include the following: develop-
or filtered air (FA) for time periods ranging from 1 d to 5 m (5 ment of nanoscale reference materials for instrument and
h/d; 5 d/w). At 24-hr post exposure, tension studies were con- method validation, laboratory qualification, and benchmark-
ducted to evaluate vascular function in response to a vasocon- ing, and to support interlaboratory comparisons; studies
strictors and -dilators in the carotid artery. Results indicated to develop standardized dispersion protocols for ENMs in
that arteries from NHNP mice showed statistically significant biological and environmental test media, and to evaluate
differences in contractile and relaxation responses compared current practices; research to assess the physicochemical
to those from FA mice. Oxidative stress and inflammation in stability of nanoscale Ag and Au in biological and environ-
the pulmonary and extrapulmonary system indicated dam- mental matrices; measurements to characterize and quantify
age, and the degree of plaque formation was determined in the amount, conformation, and distribution of surface-bound
the ascending aorta. In addition, three brain regions were molecular species; evaluation of methods for detection and
collected (olfactory bulb, midbrain, and cerebellum) for characterization of aggregates formed in ENM dispersions;
gene expression analyses. These results suggest that both and application of synchrotron X-ray and neutron scatter-
short- and long-term exposure to inhaled NHNPs can induce ing methods to study ENM formation, interactions, and
oxidative stress and inflammation in both pulmonary and functionalization.
extrapulmonary organs that can accelerate atherosclerosis
in ApoE-/- mice as well as alter vascular function and brain
gene expression in C57BL/6 mice.
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71
APPENDIX B
USING MASS SPECTROMETRY TO CHARACTERIZE CHARACTERIZATION OF HIDDEN NANOPARTICLES-
AIRBORNE PARTICLES POLYMER INTERFACE IN COMPOSITES
E. A. Bruns,1 V. Perraud,1 M. L. Alexander,2 A. Zelenyuk,2 M. Zhao,1 B. Ming,1 A. E. Vladar,1 X. Gu,1 and T. Nguyen1
M. J. Ezell,1 S. N. Johnson,1 J. Greaves,1 D. Imre,3 and B. J. 1National Institute of Standards and Technology, Gaith -
Finlayson-Pitts1 ersburg, MD 20899, mzhao@nist.gov
1Department of Chemistry, University of California,
The interface of nanoparticles-polymer plays an important
Irvine, CA 92697-2025
2Environmental Molecular Sciences Laboratory, Pacific role in properties and applications of nanocomposites. How-
ever, few analytical techniques are suitable for characterizing
Northwest National Laboratory, Richland, WA 99352
3Imre Consulting, Richland, WA 99352 this interface due to its small length scale and hidden natures.
In this work, the hidden nanoparticles-polymer interface in
Airborne particles affect health, reduce visibility, and composites is studied by scanning probe microscopy (SPM)
impact climate by scattering light and altering cloud proper- and scanning electron microscopy (SEM). Specifically, elec-
ties, and complete particle characterization is essential to tric force microscopy (EFM), a special type of SPM based
understand these impacts. Secondary organic aerosols (SOAs) on long-range electrostatic interactions, and poly-transparent
are a significant constituent of atmospheric particles and are SEM (PT-SEM), a newly developed SEM technique for
formed from the condensation of semi-volatile oxidation subsurface imaging, were applied in this study. The high-
products. The partitioning of these semi-volatile compounds resolution imaging of nanoparticles-polymer interface such
between the gas phase and particles makes characterization as zinc oxide-polyurethane, titanium oxide-epoxy, carbon
particularly challenging. Traditional analysis techniques nanotube-epoxy, and carbon nanotube-polyimide was dem-
involve filter-based sampling and extraction, which can onstrated. The effect of experimental parameters of EFM
introduce artifacts. In the past decade, real-time particle and PT-SEM on interface imaging was also discussed. In
mass spectrometry has emerged as a powerful technique that particular, EFM and PT-SEM are nondestructive techniques
overcomes these artifacts. However, their response to organic for the nanoscale characterization of hidden interface in both
nitrates, which are present in SOAs, is unknown. Ambient thin film and bulk samples without any sample prepara-
ionization mass spectrometry has also emerged as a promising tions. Hence, EFM and PT-SEM will be powerful tools not
technique for particulate analysis because little or no sample only for the characterization of hidden interface in nano-
preparation is needed and Fourier transform infrared (FTIR) composites, but also for a broad range of other nanotech-
spectra of the same sample can be obtained. We report here nology applications.
results from the analysis of laboratory-generated SOAs from
the oxidation of several terpenes, including a-pinene, using
high-resolution time-of-flight aerosol mass spectrometry
(HR-ToF-AMS), atmospheric solids analysis probe mass
spectrometry (ASAP-MS), and FTIR. The ability of HR-
ToF-AMS, a real-time technique, to analyze organic nitrates
will be explored, as will the applicability of ASAP-MS, an
ambient ionization technique, to particulate analysis.
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