@article {83,
	title = {Heterogeneous Reactivity of Nitric Acid with Nascent Sea Spray Aerosol: Large Differences Observed between and within Individual Particles.},
	journal = {Journal of Physical Chemistry Letters},
	volume = {5},
	year = {2014},
	note = {CAPLUS AN 2014:1085495(Journal; Online Computer File)},
	pages = {2493 - 2500},
	publisher = {American Chemical Society},
	abstract = {Current climate and atm. chem. models assume that all sea spray particles react as if they are pure NaCl.  However, recent studies of sea spray aerosol particles have shown that distinct particle types exist (including sea salt, org. C, and biol. particles) as well as mixts. of these and, within each particle type, there is a range of single-particle chem. compns.  Because of these differences, individual particles should display a range of reactivities with trace atm. gases.  We studied the compn. of individual sea spray aerosol particles after heterogeneous reaction with nitric acid.  As expected, a replacement reaction of chloride with nitrate is obsd.; however, there is a large range of reactivities spanning from no reaction to complete reaction between and within individual sea spray aerosol particles.  These data clearly support the need for lab. studies of individual, environmentally relevant particles to improve our fundamental understanding as to the properties that det. reactivity. [on SciFinder(R)]},
	keywords = {heterogeneous reactivity nitrate nascent sea spray aerosol},
	isbn = {1948-7185},
	author = {Ault, Andrew P. and Guasco, Timothy L. and Baltrusaitis, Jonas and Ryder, Olivia S. and Trueblood, Jonathan V. and Collins, Douglas B. and Ruppel, Matthew J. and Cuadra-Rodriguez, Luis A. and Prather, Kimberly A. and Grassian, Vicki H.}
}
@article {86,
	title = {Iron oxide nanoparticles induce Pseudomonas aeruginosa growth, induce biofilm formation, and inhibit antimicrobial peptide function.},
	journal = {Environmental Science: Nano},
	volume = {1},
	year = {2014},
	note = {CAPLUS AN 2014:465811(Journal; Online Computer File)},
	pages = {123 - 132},
	publisher = {Royal Society of Chemistry},
	abstract = {Given the increased use of iron-contg. nanoparticles in a no. of applications, it is important to understand any effects that iron-contg. nanoparticles can have on the environment and human health.  Since iron concns. are extremely low in body fluids, there is potential that iron-contg. nanoparticles may influence the ability of bacteria to scavenge iron for growth, affect virulence and inhibit antimicrobial peptide (AMP) function.  In this study, Pseudomonas aeruginosa (PA01) and AMPs were exposed to iron oxide nanoparticles, hematite (α-Fe2O3), of different sizes ranging from 2 to 540 nm (2 {\textpm} 1, 43 {\textpm} 6, 85 {\textpm} 25 and 540 {\textpm} 90 nm) in diam.  Here we show that the greatest effect on bacterial growth, biofilm formation, and AMP function impairment is found when exposed to the smallest particles.  These results are attributed in large part to enhanced dissoln. obsd. for the smallest particles and an increase in the amt. of bioavailable iron.  Furthermore, AMP function can be addnl. impaired by adsorption onto nanoparticle surfaces.  In particular, lysozyme readily adsorbs onto the nanoparticle surface which can lead to loss of peptide activity.  Thus, this current study shows that co-exposure of nanoparticles and known pathogens can impact host innate immunity.  Therefore, it is important that future studies be designed to further understand these types of impacts. [on SciFinder(R)]},
	keywords = {Pseudomonas iron oxide nanoparticle biofilm antimicrobial peptide},
	isbn = {2051-8161},
	author = {Borcherding, Jennifer and Baltrusaitis, Jonas and Chen, Haihan and Stebounova, Larissa and Wu, Chia-Ming and Rubasinghege, Gayan and Mudunkotuwa, Imali A. and Caraballo, Juan Carlos and Zabner, Joseph and Grassian, Vicki H. and Comellas, Alejandro P.}
}
@article {95,
	title = {Surface Photochemistry of Adsorbed Nitrate: The Role of Adsorbed Water in the Formation of Reduced Nitrogen Species on α-Fe2O3 Particle Surfaces.},
	journal = {Journal of Physical Chemistry A},
	volume = {118},
	year = {2014},
	note = {CAPLUS AN 2013:1898077(Journal; Online Computer File)},
	pages = {158 - 166},
	publisher = {American Chemical Society},
	abstract = {The surface photochem. of nitrate, formed from nitric acid adsorption, on hematite (α-Fe2O3) particle surfaces under different environmental conditions is investigated using XPS.  Following exposure of α-Fe2O3 particle surfaces to gas-phase nitric acid, a peak in the N1s region is seen at 407.4 eV; this binding energy is indicative of adsorbed nitrate.  Upon broadband irradn. with light (λ > 300 nm), the nitrate peak decreases in intensity as a result of a decrease in adsorbed nitrate on the surface.  Concomitant with this decrease in the nitrate coverage, there is the appearance of two lower binding energy peaks in the N1s region at 401.7 and 400.3 eV, due to reduced nitrogen species.  The formation as well as the stability of these reduced nitrogen species, identified as NO- and N-, are further investigated as a function of water vapor pressure.  Addnl., irradn. of adsorbed nitrate on α-Fe2O3 generates three nitrogen gas-phase products including NO2, NO, and N2O.  As shown here, different environmental conditions of water vapor pressure and the presence of mol. oxygen greatly influence the relative photoproduct distribution from nitrate surface photochem.  The atm. implications of these results are discussed. [on SciFinder(R)]},
	keywords = {surface photochem nitrate nitric acid adsorbate iron oxide particle},
	isbn = {1089-5639},
	author = {Nanayakkara, Charith E. and Jayaweera, Pradeep M. and Rubasinghege, Gayan and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {98,
	title = {Bringing the ocean into the laboratory to probe the chemical complexity of sea spray aerosol.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {110},
	year = {2013},
	note = {CAPLUS AN 2013:915844(Journal)},
	pages = {7550-7555, S7550/1-S7550/10},
	publisher = {National Academy of Sciences},
	abstract = {The prodn., size, and chem. compn. of sea spray aerosol (SSA) particles strongly depend on seawater chem., which is controlled by phys., chem., and biol. processes.  Despite decades of marine environment studies, a direct relationship has yet to be established between ocean biol. and physicochem. SSA properties.  The ability to establish such relationships is hindered because SSA measurements are typically dominated by overwhelming background aerosol concns., even in remote marine environments.  This work describes a newly developed approach to reproduce SSA chem. complexity a lab. setting, comprising a unique ocean/atm. facility equipped with actual breaking waves.  A mesocosm expt., performed with natural seawater using controlled phytoplankton and heterotrophic bacteria concns., showed SSA size and chem. mixing state are acutely sensitive to the aerosol prodn. mechanism and to the type of biol. species present.  The largest redn. in SSA hygroscopicity occurred as heterotrophic bacteria concns. increased, whereas phytoplankton and chlorophyll-a concns. decreased, directly corresponding to a change in mixing state in the smallest size range (60-180 nm).  Using this newly developed approach to generate realistic SSA, systematic studies can now be performed to advance the fundamental understanding of the effect of ocean biol. on SSA chem. mixing state, heterogeneous reactivity, and resulting climate-relevant properties. [on SciFinder(R)]},
	keywords = {air pollution sea spray aerosol, chem mixing state heterogeneous reactivity sea spray aerosol, controlled heterotrophic bacteria phytoplankton addn sea spray aerosol, sea spray aerosol prodn size chem compn assessment facility},
	isbn = {0027-8424},
	author = {Prather, Kimberly A. and Bertram, Timothy H. and Grassian, Vicki H. and Deane, Grant B. and Stokes, M. Dale and DeMott, Paul J. and Aluwihare, Lihini I. and Palenik, Brian P. and Azam, Farooq and Seinfeld, John H. and Moffet, Ryan C. and Molina, Mario J. and Cappa, Christopher D. and Geiger, Franz M. and Roberts, Gregory C. and Russell, Lynn M. and Ault, Andrew P. and Baltrusaitis, Jonas and Collins, Douglas B. and Corrigan, Craig E. and Cuadra-Rodriguez, Luis A. and Ebben, Carlena J. and Forestieri, Sara D. and Guasco, Timothy L. and Hersey, Scott P. and Kim, Michelle J. and Lambert, William F. and Modini, Robin L. and Mui, Wilton and Pedler, Byron E. and Ruppel, Matthew J. and Ryder, Olivia S. and Schoepp, Nathan G. and Sullivan, Ryan C. and Zhao, Defeng.}
}
@article {99,
	title = {Coal fly ash impairs airway antimicrobial peptides and increases bacterial growth.},
	journal = {PLoS One},
	volume = {8},
	year = {2013},
	note = {CAPLUS AN 2013:396251(Journal; Online Computer File)},
	pages = {e57673},
	publisher = {Public Library of Science},
	abstract = {Air pollution is a risk factor for respiratory infections, and one of its main components is particulate matter (PM), which is comprised of a no. of particles that contain iron, such as coal fly ash (CFA).  Since free iron concns. are extremely low in airway surface liq. (ASL), we hypothesize that CFA impairs antimicrobial peptides (AMP) function and can be a source of iron to bacteria.  We tested this hypothesis in vivo by instilling mice with Pseudomonas aeruginosa (PA01) and CFA and det. the percentage of bacterial clearance.  In addn., we tested bacterial clearance in cell culture by exposing primary human airway epithelial cells to PA01 and CFA and detg. the AMP activity and bacterial growth in vitro.  We report that CFA is a bioavailable source of iron for bacteria.  We show that CFA interferes with bacterial clearance in vivo and in primary human airway epithelial cultures.  Also, we demonstrate that CFA inhibits AMP activity in vitro, which we propose as a mechanism of our cell culture and in vivo results.  Furthermore, PA01 uses CFA as an iron source with a direct correlation between CFA iron dissoln. and bacterial growth.  CFA concns. used are very relevant to human daily exposures, thus posing a potential public health risk for susceptible subjects.  Although CFA provides a source of bioavailable iron for bacteria, not all CFA particles have the same biol. effects, and their propensity for iron dissoln. is an important factor.  CFA impairs lung innate immune mechanisms of bacterial clearance, specifically AMP activity.  We expect that identifying the PM mechanisms of respiratory infections will translate into public health policies aimed at controlling, not only concn. of PM exposure, but physicochem. characteristics that will potentially cause respiratory infections in susceptible individuals and populations. [on SciFinder(R)]},
	isbn = {1932-6203},
	author = {Borcherding, Jennifer A. and Chen, Haihan and Caraballo, Juan C. and Baltrusaitis, Jonas and Pezzulo, Alejandro A. and Zabner, Joseph and Grassian, Vicki H. and Comellas, Alejandro P.}
}
@article {101,
	title = {Effects of Eyjafjallajokull volcanic ash on innate immune system responses and bacterial growth in vitro},
	journal = {Environmental health perspectives},
	volume = {121},
	year = {2013},
	note = {MEDLINE AN 2013450089(Journal; Article; (JOURNAL ARTICLE); (RESEARCH SUPPORT, N.I.H., EXTRAMURAL); (RESEARCH SUPPORT, U.S. GOV{\textquoteright}T, NON-P.H.S.))},
	pages = {691 - 8},
	abstract = {BACKGROUND:  On 20 March 2010, the Icelandic volcano Eyjafjallajokull erupted for the first time in 190 years.  Despite many epidemiological reports showing effects of volcanic ash on the respiratory system, there are limited data evaluating cellular mechanisms involved in the response to ash.  Epidemiological studies have observed an increase in respiratory infections in subjects and populations exposed to volcanic eruptions.  METHODS:  We physicochemically characterized volcanic ash, finding various sizes of particles, as well as the presence of several transition metals, including iron.  We examined the effect of Eyjafjallajokull ash on primary rat alveolar epithelial cells and human airway epithelial cells (20-100 μg/cm(2)), primary rat and human alveolar macrophages (5-20 μg/cm(2)), and Pseudomonas aeruginosa (PAO1) growth (3 μg/104 bacteria).  RESULTS:  Volcanic ash had minimal effect on alveolar and airway epithelial cell integrity.  In alveolar macrophages, volcanic ash disrupted pathogen-killing and inflammatory responses.  In in vitro bacterial growth models, volcanic ash increased bacterial replication and decreased bacterial killing by antimicrobial peptides.  CONCLUSIONS:  These results provide potential biological plausibility for epidemiological data that show an association between air pollution exposure and the development of respiratory infections.  These data suggest that volcanic ash exposure, while not seriously compromising lung cell function, may be able to impair innate immunity responses in exposed individuals.[on SciFinder (R)]},
	isbn = {1552-9924},
	author = {Monick, Martha M. and Baltrusaitis, Jonas and Powers, Linda S. and Borcherding, Jennifer A. and Caraballo, Juan C. and Mudunkotuwa, Imali and Peate, David W. and Walters, Katherine and Thompson, Jay M. and Grassian, Vicki H. and Gudmundsson, Gunnar and Comellas, Alejandro P.}
}
@article {105,
	title = {Heterogeneous Uptake and Adsorption of Gas-Phase Formic Acid on Oxide and Clay Particle Surfaces: The Roles of Surface Hydroxyl Groups and Adsorbed Water in Formic Acid Adsorption and the Impact of Formic Acid Adsorption on Water Uptake.},
	journal = {Journal of Physical Chemistry A},
	volume = {117},
	year = {2013},
	note = {CAPLUS AN 2013:1536458(Journal; Online Computer File)},
	pages = {11316 - 11327},
	publisher = {American Chemical Society},
	abstract = {Org. acids in the atm. are ubiquitous and are often correlated with mineral dust aerosol.  Heterogeneous chem. and the uptake of org. acids on mineral dust particles can potentially alter the properties of the particle.  In this study, heterogeneous uptake and reaction of formic acid, HCOOH, the most abundant carboxylic acid present in the atm., on oxide and clays of the most abundant elements, Si and Al, present in the Earth{\textquoteright}s crust are investigated under dry and humid conditions.  In particular, quant. adsorption measurements using a Quartz Crystal Microbalance (QCM) coupled with spectroscopic studies using Attenuated Total Reflection Fourier Transform IR (ATR-FTIR) spectroscopy are combined to allow for both quantification of the amt. of uptake and identification of distinct adsorbed species formed on silica, alumina, and kaolinite particle surfaces at 298 K.  These oxides and clay particles show significant differences in the extent and speciation of adsorbed HCOOH due to inherent differences in surface -OH group reactivity.  Adsorbed water, controlled by relative humidity, can increase the irreversible uptake of formic acid.  Interestingly, the resulting layer of adsorbed formate on the particle surface decreases the particle hydrophilicity thereby decreasing the amt. of water taken up by the surface as measured by QCM.  Atm. implications of this study are discussed. [on SciFinder(R)]},
	keywords = {heterogeneous uptake adsorption gas phase formic acid oxide clay},
	isbn = {1089-5639},
	author = {Rubasinghege, Gayan and Ogden, Saralyn and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {109,
	title = {Inside versus Outside: Ion Redistribution in Nitric Acid Reacted Sea Spray Aerosol Particles as Determined by Single Particle Analysis.},
	journal = {Journal of the American Chemical Society},
	volume = {135},
	year = {2013},
	note = {CAPLUS AN 2013:1428969(Journal; Online Computer File)},
	pages = {14528 - 14531},
	publisher = {American Chemical Society},
	abstract = {Single particle anal. of individual sea spray aerosol particles showed cations (Na+, K+, Mg2+, Ca2+) within individual particles undergo a spatial redistribution following heterogeneous reaction with HNO3, along with development of a more concd. layer of org. matter at the particle surface.  These data suggested specific ion and aerosol pH effects play an important role in aerosol particle structure in ways not previously recognized. [on SciFinder(R)]},
	keywords = {ion redistribution sea spray aerosol particle nitric acid reaction, single particle analysis monitoring ion redistribution sea spray aerosol},
	isbn = {0002-7863},
	author = {Ault, Andrew P. and Guasco, Timothy L. and Ryder, Olivia S. and Baltrusaitis, Jonas and Cuadra-Rodriguez, Luis A. and Collins, Douglas B. and Ruppel, Matthew J. and Bertram, Timothy H. and Prather, Kimberly A. and Grassian, Vicki H.}
}
@article {115,
	title = {Size-Dependent Changes in Sea Spray Aerosol Composition and Properties with Different Seawater Conditions.},
	journal = {Environmental Science \& Technology},
	volume = {47},
	year = {2013},
	note = {CAPLUS AN 2013:690844(Journal; Online Computer File)},
	pages = {5603 - 5612},
	publisher = {American Chemical Society},
	abstract = {Much uncertainty exists regarding the chem. diversity of particles in sea spray aerosol (SSA) and the degree of mixing between inorg. and org. species in individual SSA particles.  Single particle anal. of SSA particles was performed, integrating transmission electron microscopy with energy dispersive x-ray anal. and scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy, focusing on quantifying the relative fractions of different particle types from 30 nm to 1 μm.  SSA particles were produced from seawater in a unique ocean/atm. facility equipped with breaking waves.  Changes to SSA compn. and properties after adding biol. (bacteria, phytoplankton) and org. material (ZoBell growth media) were probed.  Sub-micrometer SSA particles could be sepd. into 2 distinct populations: one with a characteristic sea-salt core composed primarily of NaCl and an org. C and Mg2+ coating (SS-OC); and a second type consisting of org. C (OC) species more homogeneously mixed with cations and anions, but not Cl-.  SS-OC particles exhibited a range of sizes, compns., morphologies, and element distributions within each particle.  Following addn. of biol. and org. material to seawater, a change occurred in particle morphol. and crystn. behavior assocd. with increasing org. content for SS-OC particles.  The fraction of OC-type particles, mainly present at <180 nm, was dramatically enhanced with increased biol. activity.  These changes with size and seawater compn. have important implications for atm. processes, e.g., cloud droplet activation and heterogeneous reactivity. [on SciFinder(R)]},
	keywords = {size dependent change sea spray aerosol compn},
	isbn = {0013-936X},
	author = {Ault, Andrew P. and Moffet, Ryan C. and Baltrusaitis, Jonas and Collins, Douglas B. and Ruppel, Matthew J. and Cuadra-Rodriguez, Luis A. and Zhao, Defeng and Guasco, Timothy L. and Ebben, Carlena J. and Geiger, Franz M. and Bertram, Timothy H. and Prather, Kimberly A. and Grassian, Vicki H.}
}
@article {128,
	title = {Atomic Force Microscopy and X-ray Photoelectron Spectroscopy Study of NO2 Reactions on CaCO3 (101̅4) Surfaces in Humid Environments.},
	journal = {Journal of Physical Chemistry A},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:1112006(Journal; Online Computer File)},
	pages = {9001 - 9009},
	publisher = {American Chemical Society},
	abstract = {A.c. (a.c.) mode at. force microscopy (AFM) combined with phase imaging and XPS were used to study the effect of nitrogen dioxide (NO2) adsorption on calcium carbonate (CaCO3) (101̅4) surfaces at 296 K in the presence of relative humidity (RH).  At 70\% RH, CaCO3 (101̅4) surfaces undergo rapid formation of a metastable amorphous calcium carbonate layer, which in turn serves as a substrate for recrystn. of a nonhydrated calcite phase, presumably vaterite.  The adsorption of nitrogen dioxide changes the surface properties of CaCO3 (101̅4) and the mechanism for formation of new phases.  In particular, the 1st calcite nucleation layer serves as a source of material for further island growth; when it is depleted, there is no change in total vol. of nitrocalcite, Ca(NO3)2, particles formed whereas the total no. of particles decreases.  These particles are mobile and coalesce.  Phase imaging combined with force curve measurements reveals areas of inhomogeneous energy dissipation during the process of water adsorption in relative humidity expts., as well as during nitrocalcite particle formation.  Potential origins of the different energy dissipation modes within the sample are discussed.  Finally, XPS anal. confirms that NO2 adsorbs on CaCO3 (101̅4) as nitrate (NO3-) regardless of environmental conditions or the pretreatment of the calcite surface at different relative humidity. [on SciFinder(R)]},
	keywords = {atomic force microscopy XPS nitrogen oxide adsorption calcium carbonate},
	isbn = {1089-5639},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {129,
	title = {Coal fly ash as iron source in atmospheric dust.},
	journal = {Environmental Science \& Technology},
	volume = {46},
	year = {2012},
	note = {CAPLUS AN 2012:79841(Journal; Online Computer File)},
	month = {2012///},
	pages = {2112 - 2120},
	publisher = {American Chemical Society},
	abstract = {Anthropogenic coal fly ash (FA) aerosol may represent a significant source of bioavailable iron in the open ocean.  Few measurements have been made that compare the soly. of atm. iron from anthropogenic aerosols and other sources.  We report here an investigation of iron dissoln. for three FA samples in acidic aq. solns. and compare the solubilities with that of Arizona test dust (AZTD), a ref. material for mineral dust.  The effects of pH, simulated cloud processing, and solar radiation on iron soly. have been explored.  Similar to previously reported results on mineral dust, iron in aluminosilicate phases provides the predominant component of dissolved iron.  Iron soly. of FA is substantially higher than of the cryst. minerals comprising AZTD.  Simulated atm. processing elevates iron soly. due to significant changes in the morphol. of aluminosilicate glass, a dominant material in FA particles.  Iron is continuously released into the aq. soln. as FA particles break up into smaller fragments.  These results suggest that the assessment of dissolved atm. iron deposition fluxes and their effect on the biogeochem. at the ocean surface should be constrained by the source, environmental pH, iron speciation, and solar radiation. [on SciFinder(R)]},
	keywords = {coal fly ash iron atm dust qual analysis aluminosilicate},
	isbn = {0013-936X},
	author = {Chen, Haihan and Laskin, Alexander and Baltrusaitis, Jonas and Gorski, Christopher A. and Scherer, Michelle M. and Grassian, Vicki H.}
}
@article {135,
	title = {Heterogeneous Atmospheric Chemistry of Lead Oxide Particles with Nitrogen Dioxide Increases Lead Solubility: Environmental and Health Implications.},
	journal = {Environmental Science \& Technology},
	volume = {46},
	year = {2012},
	note = {CAPLUS AN 2012:1499142(Journal; Online Computer File)},
	month = {2012///},
	pages = {12806 - 12813},
	publisher = {American Chemical Society},
	abstract = {The heterogeneous chem. of NO2 with Pb-contg. particles was examd. to better understand Pb metal mobilization in the environment.  In particular, PbO particles, a model Pb-contg. compd. due to its widespread presence as a Pb paint and as naturally-occurring mineral (massicot, and litharge) component, were exposed to NO2 at different relative humidities.  XPS showed that upon exposure to NO2, the PbO particle surface reacts forming adsorbed NO3- and Pb(NO3)2 thin films; the extent of NO3- formation was relatively humidity dependent.  NO2-exposed PbO particles had an increased amt. of Pb which dissolved in aq. suspensions at circumneutral pH vs. unexposed particles.  Results identified the potential importance and impact that heterogeneous chem. with trace atm. gases can have on increasing soly. and hence the mobilization of heavy metals such as Pb in the environment.  Results also showed that surface intermediates which form, such as adsorbed Pb(NO3)2, can yield higher Pb concns. in water, including drinking, estuary, and lake water, and groundwater. [on SciFinder(R)]},
	keywords = {air water soil pollution lead following nitrogen dioxide reaction, environmental health implication lead oxide reaction nitrogen dioxide, lead oxide particle heterogeneous atm chem, nitrogen dioxide reaction lead oxide particle increased lead soly},
	isbn = {0013-936X},
	author = {Baltrusaitis, Jonas and Chen, Haihan and Rubasinghege, Gayan and Grassian, Vicki H.}
}
@article {141,
	title = {Preservation of York Minster historic limestone by hydrophobic surface coatings.},
	journal = {Scientific Reports},
	volume = {2},
	year = {2012},
	note = {CAPLUS AN 2013:60154(Journal; Online Computer File)},
	month = {2012///},
	pages = {srep00880, 5 pp.},
	publisher = {Nature Publishing Group},
	abstract = {Magnesian limestone is a key construction component of many historic buildings that is under const. attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO2 emissions.  Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from {\textquoteright}breathing{\textquoteright} and promoting mold growth and salt efflorescence.  Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite.  We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation and thus retarding gypsum formation under SO2/H2O and model acid rain environments.  SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation. [on SciFinder(R)]},
	keywords = {archaeol limestone preservation surface coating},
	isbn = {2045-2322},
	author = {Walker, Rachel A. and Wilson, Karen and Lee, Adam F. and Woodford, Julia and Grassian, Vicki H. and Baltrusaitis, Jonas and Rubasinghege, Gayan and Cibin, Giannantonio and Dent, Andrew.}
}
@article {144,
	title = {Surface Chemistry of α-FeOOH Nanorods and Microrods with Gas-Phase Nitric Acid and Water Vapor: Insights into the Role of Particle Size, Surface Structure, and Surface Hydroxyl Groups in the Adsorption and Reactivity of α-FeOOH with Atmospheric Gases.},
	journal = {Journal of Physical Chemistry C},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:668168(Journal; Online Computer File)},
	month = {2012///},
	pages = {12566 - 12577},
	publisher = {American Chemical Society},
	abstract = {Heterogeneous interactions of H2O and HNO3 on goethite, α-FeOOH, a component of mineral dust aerosol, are studied with simultaneous QCM measurements and ATR-FTIR spectroscopy.  Lab. synthesized α-FeOOH of varying sizes (microrods and nanorods) when exposed to gas phase H2O and HNO3 results in the uptake of these gases.  This combined approach of QCM measurements and ATR-FTIR spectroscopy allows for both quantification of the amt. of uptake and spectroscopic data that provides information on speciation of adsorbed products.  In the case of H2O, both microrods and nanorods take up H2O and that the total amts. of H2O, when normalized to surface area, are similar.  However, for HNO3 uptake, the satn. coverage of total and irreversibly bound HNO3 on microrods is higher than that on nanorods, a size effect which is attributed to surface structural changes that occur as a function of particle size.  Also, a study of the behavior of HNO3 reacted with α-FeOOH in aq. media was carried out such as to better understand the effects of atm. processing upon dispersal within the hydrosphere. [on SciFinder(R)]},
	keywords = {iron hydroxide oxide nanorod microrod nitric acid water adsorption},
	isbn = {1932-7447},
	author = {Wijenayaka, Lahiru A. and Rubasinghege, Gayan and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {149,
	title = {Carbon dioxide adsorption on oxide nanoparticle surfaces.},
	journal = {Chemical Engineering Journal (Amsterdam, Netherlands)},
	volume = {170},
	year = {2011},
	note = {CAPLUS AN 2011:672234(Journal; Online Computer File)},
	month = {2011///},
	pages = {471 - 481},
	publisher = {Elsevier B.V.},
	abstract = {In this paper, focused on environmental nanotechnol., we review some recent results for carbon dioxide (CO2) adsorption on hydroxylated Fe2O3, γ-Al2O3, and TiO2 nanoparticle surfaces at 296 K as followed by transmission FTIR spectroscopy.  In the absence of water vapor (<1\% relative humidity, RH), following exposure to CO2 different species formed on the oxide surface due to the presence of adsorption sites with different basicities.  While the majority surface species on Fe2O3, γ-Al2O3 is detd. to be adsorbed bicarbonate, on TiO2 nanoparticles bidentate carbonate was more prevalent.  A carboxylate species was obsd. on TiO2 nanoparticles under dry conditions as well.  When water is present at 40\% RH, the nature of the adsorbed CO2 species changed to that of solvated carbonate formation in the adsorbed water layer.  Obsd. initial adsorption rates were calcd. from time-course expts. under dry conditions and in the presence of 40\% RH.  When initial adsorption rates were compared between dry and wet expts., a larger value was found for dry expts. suggesting that CO2 mols. have to compete for adsorption sites with water on these nanoparticle surfaces.  As discussed here, quantum chem. calcns. provide some addnl. insights into CO2 adsorption on hydroxylated metal oxide surfaces in the presence and absence of molecularly adsorbed water. [on SciFinder(R)]},
	keywords = {carbon dioxide adsorption oxide nanoparticle surface relative humidity water},
	isbn = {1385-8947},
	author = {Baltrusaitis, Jonas and Schuttlefield, Jennifer and Zeitler, Elizabeth and Grassian, Vicki H.}
}
@article {152,
	title = {Formation of paratacamite nanomaterials via the conversion of aged and oxidized copper nanoparticles in hydrochloric acidic media.},
	journal = {Journal of Materials Chemistry},
	volume = {21},
	year = {2011},
	note = {CAPLUS AN 2011:194197(Journal)},
	month = {2011///},
	pages = {3162 - 3169},
	publisher = {Royal Society of Chemistry},
	abstract = {Nanoparticles and nanostructured aggregates of paratacamite are prepd. in acidic solns. through the conversion of copper-based nanoparticles.  Aged and oxidized copper nanoparticles with an av. primary particle size of \~{}15 nm, when combined with hydrochloric acid solns. in the range of 0.025 to 0.1 M, show interesting behavior yielding both a change in nanoparticle primary size, as measured by an electrospray scanning mobility particle sizer, and in chem. compn. to produce a copper chloride hydroxide mineral identified as paratacamite (γ-Cu2(OH)3Cl) by powder X-ray diffraction of the dehydrated solid sample.  Taken together, these data suggest that paratacamite nanoparticles in soln. can aggregate to yield microporous paratacamite materials.  Microporous paratacamite was characterized by several techniques including X-ray diffraction, transmission electron microscopy, energy dispersive X-ray anal., electron energy loss spectroscopy, XPS and surface area measurements.  Oxidn. of these copper-based nanoparticles with mol. oxygen and the role of the oxidized layer in the formation of paratacamite have been investigated.  Comparison to microscale copper particles showed there is unique oxidn. behavior of nanoscale copper particles that results in unique reaction chem. of oxidized nanoscale copper particles with hydrochloric acid solns. to form paratacamite.  This study provides a new route for the formation of paratacamite nanomaterials that can be used in a wide range of chem. interesting applications including hydrogen storage materials and as a heterogeneous catalyst for the synthesis of green solvents such as di-Me and di-Et carbonates.  Addnl., this study suggests a potentially new pathway for the degrdn. of art objects and ancient artifacts as well as other cultural heritage materials contg. small copper particles that has not been previously considered. [on SciFinder(R)]},
	keywords = {conversion aged oxidized copper nanoparticle hydrochloric acidic medium, formation paratacamite nanomaterial},
	isbn = {0959-9428},
	author = {Elzey, Sherrie and Baltrusaitis, Jonas and Bian, Shaowei and Grassian, Vicki H.}
}
@article {153,
	title = {Induction of Inflammasome-dependent Pyroptosis by Carbon Black Nanoparticles.},
	journal = {Journal of Biological Chemistry},
	volume = {286},
	year = {2011},
	note = {CAPLUS AN 2011:737835(Journal)},
	month = {2011///},
	pages = {21844 - 21852},
	publisher = {American Society for Biochemistry and Molecular Biology},
	abstract = {Inhalation of nanoparticles has been implicated in respiratory morbidity and mortality.  In particular, carbon black nanoparticles are found in many different environmental exposures.  Macrophages take up inhaled nanoparticles and respond via release of inflammatory mediators and in some cases cell death.  Based on new data, we propose that exposure of macrophages (both a macrophage cell line and primary human alveolar macrophages) to carbon black nanoparticles induces pyroptosis, an inflammasome-dependent form of cell death.  Exposure of macrophages to carbon black nanoparticles resulted in inflammasome activation as defined by cleavage of caspase 1 to its active form and downstream IL-1β release.  The cell death that occurred with carbon black nanoparticle exposure was identified as pyroptosis by the protective effect of a caspase 1 inhibitor and a pyroptosis inhibitor.  These data demonstrate that carbon black nanoparticle exposure activates caspase 1, increases IL-1β release after LPS priming, and induces the proinflammatory cell death, pyroptosis.  The identification of pyroptosis as a cellular response to carbon nanoparticle exposure is novel and relates to environmental and health impacts of carbon-based particulates. [on SciFinder(R)]},
	keywords = {carbon black nanoparticle immunotoxicity inflammasome pyroptosis},
	isbn = {0021-9258},
	author = {Reisetter, Anna C. and Stebounova, Larissa V. and Baltrusaitis, Jonas and Powers, Linda and Gupta, Amit and Grassian, Vicki H. and Monick, Martha M.}
}
@article {159,
	title = {Sulfur Dioxide Adsorption on TiO2 Nanoparticles: Influence of Particle Size, Coadsorbates, Sample Pretreatment, and Light on Surface Speciation and Surface Coverage.},
	journal = {Journal of Physical Chemistry C},
	volume = {115},
	year = {2011},
	note = {CAPLUS AN 2010:1546849(Journal; Online Computer File)},
	month = {2011///},
	pages = {492 - 500},
	publisher = {American Chemical Society},
	abstract = {The adsorption of sulfur dioxide (SO2) on titanium dioxide (TiO2) nanoparticle surfaces at 296 K under a wide range of conditions has been investigated.  XPS is used to investigate the surface speciation and surface coverage of sulfur-contg. products on ca. 4 nm TiO2 anatase particles that remain on the surface following adsorption of SO2.  The effects of various environmental conditions of relative humidity, mol. oxygen, and broadband UV/vis irradn. as well as sample pretreatment were found to impact the speciation of adsorbed SO2 as well as the satn. coverage.  In particular, in the absence of light, the majority surface species upon SO2 adsorption is found to be adsorbed sulfite.  Broadband UV/vis irradn. during sulfur dioxide adsorption leads to an increase (nearly 2-fold) in the amt. of adsorbed sulfur species, as compared to expts. with no light, and results in the formation of adsorbed sulfate.  The formation of sulfate was quant. in the presence of mol. oxygen.  New surface species including chemisorbed mol. SO2 were obsd. on samples that have been reduced in vacuum through argon ion sputtering.  The total amt. of adsorbed sulfur was impacted by surface hydroxyl group coverage and molecularly adsorbed water layer.  Addnl., comparison of sulfur dioxide adsorption on 4 vs. 32 nm sized anatase nanoparticles showed that surface satn. coverages of adsorbed sulfite on the 4 nm particles was almost twice that of 32 nm particles as measured by the S2p:Ti2p peak area ratios, thus showing an increase in the inherent adsorption capacity of the smaller particles.  Proposed adsorption sites and mechanisms to account for the obsd. exptl. data are discussed. [on SciFinder(R)]},
	keywords = {adsorption sulfur dioxide titania nanoparticle surface speciation irradn},
	isbn = {1932-7447},
	author = {Baltrusaitis, Jonas and Jayaweera, Pradeep M. and Grassian, Vicki H.}
}
@article {160,
	title = {Sulfur Dioxide Adsorption on ZnO Nanoparticles and Nanorods.},
	journal = {Journal of Physical Chemistry C},
	volume = {115},
	year = {2011},
	note = {CAPLUS AN 2011:546775(Journal; Online Computer File)},
	month = {2011///},
	pages = {10164 - 10172},
	publisher = {American Chemical Society},
	abstract = {ZnO nanomaterials, nanoparticles, and nanorods, were synthesized over a wide range of sizes with relatively high yield (\~{}90-95\%).  The synthesis method allows for size control by varying the amt. of water used and morphol. control by varying the zinc precursor (zinc acetate for nanoparticles or zinc acetylacetonate for nanorods).  These nanomaterials were analyzed with powder x-ray diffraction and attenuated total reflection FTIR spectroscopy.  Sulfur dioxide adsorption on nanoparticles and nanorods of different size was then studied using volumetric measurements, transmission FTIR spectroscopy, and XPS.  Nanoparticles and nanorods of several different sizes were heated to 550{\textdegree} to remove surface-adsorbed org. ligands that remained after the synthesis prior to exposure to SO2.  Spectroscopic anal. revealed the formation of several surface species, including sulfate, sulfite, sulfide, and weakly bound SO2.  Quantifying surface speciation as well as the total amt. of adsorbed sulfur from XPS and volumetric data reveals that sulfur speciation as well as the total amt. of adsorbed sulfur is a function of particle size and morphol. [on SciFinder(R)]},
	keywords = {sulfur dioxide adsorption zinc oxide nanoparticle nanorod},
	isbn = {1932-7447},
	author = {Wu, Chia-Ming and Baltrusaitis, Jonas and Gillan, Edward G. and Grassian, Vicki H.}
}
@article {164,
	title = {Carbonic Acid Formation from Reaction of Carbon Dioxide and Water Coordinated to Al(OH)3: A Quantum Chemical Study.},
	journal = {Journal of Physical Chemistry A},
	volume = {114},
	year = {2010},
	note = {CAPLUS AN 2010:112419(Journal)},
	month = {2010///},
	pages = {2350 - 2356},
	publisher = {American Chemical Society},
	abstract = {D. functional and ab initio calcns. have been performed on CO2-nH2O and Al(OH)3-CO2-nH2O (where n = 1, 2, 3) cluster models to elucidate the catalytic effect of a hydroxylated metal center on the formation of carbonic acid (H2CO3).  B3LYP/6-311++G(d,p)-calcd. geometries and RI-SCS-MP2/aug-cc-pVTZ//B3LYP/6-311++G(d,p)-calcd. energies with respect to isolated gas-phase mols. and various H2O, CO2, and H2CO3-Al(OH)3 complexes are presented.  It is shown here that H2CO3 formation proceeds via direct CO2 and nH2O reaction with very high activation barriers in the gas phase, 51.40, 29.64, and 19.84 kcal/mol for CO2-H2O, CO2-2H2O, and CO2-3H2O clusters, resp., decreasing in magnitude with an increase in the no. of H2O mols.  The energetics as well as the reaction mechanism and energy landscape change significantly when carbonic acid is formed from CO2 and nH2O in the presence of Al(OH)3, a hydroxylated metal center.  Results presented here show important details of the influence of the coordinating metal center in the formation of H2CO3. [on SciFinder(R)]},
	keywords = {carbonic acid formation quantum chem, reaction carbon dioxide water coordinated aluminum hydroxide quantum chem},
	isbn = {1089-5639},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {170,
	title = {Reactions on Atmospheric Dust Particles: Surface Photochemistry and Size-Dependent Nanoscale Redox Chemistry.},
	journal = {Journal of Physical Chemistry Letters},
	volume = {1},
	year = {2010},
	note = {CAPLUS AN 2010:616561(Journal; General Review; Online Computer File)},
	month = {2010///},
	pages = {1729 - 1737},
	publisher = {American Chemical Society},
	abstract = {A review concerning new mechanisms and reaction pathways identified in lab. studies of atm. mineral dust and nano-dust (potential new source of metal-contg. dust from engineered nano-materials) components, particularly surface photochem. and size-dependent, nano-scale redox chem. is given. [on SciFinder(R)]},
	keywords = {review airborne dust nanodust reaction, size depended nanoscale redox chem airborne dust review, surface photochem airborne dust nanodust review},
	isbn = {1948-7185},
	url = {http://pubs.acs.org/doi/pdfplus/10.1021/jz100371d},
	author = {Rubasinghege, Gayan and Elzey, Sherrie and Baltrusaitis, Jonas and Jayaweera, Pradeep M. and Grassian, Vicki H.}
}
@article {163,
	title = {A template-free, thermal decomposition method to synthesize mesoporous MgO with a nanocrystalline framework and its application in carbon dioxide adsorption.},
	journal = {Journal of Materials Chemistry},
	volume = {20},
	year = {2010},
	note = {CAPLUS AN 2010:1212416(Journal)},
	month = {2010///},
	pages = {8705 - 8710},
	publisher = {Royal Society of Chemistry},
	abstract = {Alk. earth-based oxides are important materials for CO2 storage.  A template-free method to synthesize meso-porous MgO by thermal decompn. of anhyd. magnesium acetate is presented.  Characterization of cryst. phase, particle and pore sizes, and surface area for mesoporous MgO was done using a variety of techniques: SEM, high resoln. transmission electron microscopy, powder x-ray diffraction, and N2 adsorption anal.  Results showed meso-porous MgO synthesized from anhyd. magnesium acetate had a high surface area (120-136 m2/g) and a narrow pore size distribution (3-4 nm).  The pore was comprised of small, primary MgO nano-particle aggregates with inter-particle connections.  In-situ transmission Fourier transform IR spectroscopy assessed CO2 adsorption by meso-porous MgO.  This spectroscopic assessment showed meso-porous MgO exhibited enhanced CO2 adsorption capacity vs. com. available MgO nano-particles.  This difference was mainly attributed to increased surface area.  Differences in surface carbonate/bicarbonate speciation, obsd. between meso-porous and com. MgO, were related to structural differences of the smaller nano-particles. [on SciFinder(R)]},
	keywords = {air purifn carbon dioxide adsorption mesoporous magnesia, template free thermal decompn synthesis magnesia sorbent},
	isbn = {0959-9428},
	author = {Bian, Shao-Wei and Baltrusaitis, Jonas and Galhotra, Pragati and Grassian, Vicki H.}
}
@article {173,
	title = {Calcite ( 1 0 1 4 ) surface in humid environments.},
	journal = {Surface Science},
	volume = {603},
	year = {2009},
	note = {CAPLUS AN 2009:1033091(Journal)},
	month = {2009///},
	pages = {L99-L104},
	publisher = {Elsevier B.V.},
	abstract = {A.c. mode At. Force Microscopy (AFM) height images combined with force measurements and phase imaging were used to investigate the surface reconstruction and chem. of the lowest energy surface, ( 1 0 1 4 ) plane, of calcite, a stable form of calcium carbonate (CaCO3), in the presence of relative humidity at different temps.  At 296 K and 70\% RH, calcite ( 1 0 1 4 ) undergoes rapid restructuring during hydration forming regions on the surface that are most likely characterized as an amorphous hydrate layer similar to what forms in soln. under high [Ca2+] supersatn. conditions.  This hydrate layer in turn serves as a substrate for the crystn. of another layer that possesses structural properties which differ from hydrate layer.  Phase imaging reveals that these different layer structures formed in the process of water adsorption and surface reconstruction have very different energy dissipation modes.  The origin of the different dissipation modes are likely due to differences in water content and hydrophobicity of these regions.  The newly formed layer on top of the hydration layer is proposed to be vaterite, another polymorph of CaCO3.  At 278 K the formation mechanism of the vaterite layer changes due to nucleation of a more cryst. hydrate layer, similar to CaCO3 hexahydrate, instead of the amorphous hydrate layer that forms at 296 K.  Force measurements corroborate the assignment of the speciation of different regions on the surface.  Importantly, the AFM data show that the surface of calcite is highly inhomogeneous with regions that vary in water content.  The reactivity of calcite in humid environments will be highly spatially dependent. [on SciFinder(R)]},
	keywords = {calcite surface humidity hydration vaterite nucleation},
	isbn = {0039-6028},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {176,
	title = {XPS study of nitrogen dioxide adsorption on metal oxide particle surfaces under different environmental conditions.},
	journal = {Physical Chemistry Chemical Physics},
	volume = {11},
	year = {2009},
	note = {CAPLUS AN 2009:1128237(Journal)},
	month = {2009///},
	pages = {8295 - 8305},
	publisher = {Royal Society of Chemistry},
	abstract = {The adsorption of nitrogen dioxide on gamma aluminum oxide (γ-Al2O3) and alpha iron oxide (α-Fe2O3) particle surfaces under various conditions of relative humidity, presence of mol. oxygen and UV light has been investigated.  XPS is used to monitor the different surface species that form under these environmental conditions.  Adsorption of NO2 on aluminum oxide particle surfaces results primarily in the formation of surface nitrate, NO3- with an oxidn. state of +5, as indicated by a peak with binding energy of 407.3 eV in the N1s region.  An addnl. minority species, sensitive to the presence of relative humidity and mol. oxygen, is also obsd. in the N1s region with lower binding energy of 405.9 eV.  This peak is assigned to a surface species in the +4 oxidn. state.  When irradiated with UV light, other species form on the surface.  These surface-bound photochem. products all have lower binding energy, between 400 and 402 eV, indicating reduced nitrogen species in the range of N oxidns. states spanning +1 to -1.  Co-adsorbed water decreases the amt. of these reduced surface-bound products while the presence of mol. oxygen completely suppresses the formation of all reduced nitrogen species on aluminum oxide particle surfaces.  For NO2 on iron oxide particle surfaces, photoredn. is enhanced relative to γ-Al2O3 and surface bound photoreduced species are obsd. under all environmental conditions.  Complementing the exptl. data, N1s core electron binding energies (CEBEs) were calcd. using DFT for a no. of nitrogen-contg. species in the gas phase and adsorbed on an Al8O12 cluster.  A range of CEBEs is calcd. for various nitrogen species in different adsorption modes and oxidn. states.  These calcd. values are discussed in light of the peaks obsd. in the XPS N1s region and the possible species that form following NO2 adsorption and photoreaction on metal oxide particle surfaces under different conditions of relative humidity, presence of mol. oxygen and UV light. [on SciFinder(R)]},
	keywords = {nitrogen dioxide adsorbed metal oxide surface species XPS, oxygen nitrogen dioxide adsorbed metal oxide surface species XPS, UV nitrogen dioxide adsorbed metal oxide surface species XPS, water nitrogen dioxide adsorbed metal oxide surface species XPS},
	isbn = {1463-9076},
	author = {Baltrusaitis, Jonas and Jayaweera, Pradeep M. and Grassian, Vicki H.}
}
@article {180,
	title = {Characterization and acid-mobilization study of iron-containing mineral dust source materials.},
	journal = {Journal of Geophysical Research, [Atmospheres]},
	volume = {113},
	year = {2008},
	note = {CAPLUS AN 2008:617952(Journal)},
	month = {2008///},
	pages = {D05202/1-D05202/18},
	publisher = {American Geophysical Union},
	abstract = {Processes that solubilize iron in mineral dust aerosol may increase the amt. of iron supplied to ocean surface waters, and thereby stimulate phytoplankton productivity.  In particular, the uptake of acids such as H2SO4 and HNO3 on mineral dust surfaces can produce extremely acidic environments that promote iron dissoln.  Here, four samples that represent source materials for mineral dust (Saudi Beach sand (SB), Inland Saudi sand (IS), Saharan Sand (SS) and China Loess (CL)) and one com. ref. material (Arizona Test Dust (AZTD)) were characterized, and examd. in dissoln. studies in solns. of sulfuric, nitric and hydrochloric acid ranging from pH 1 to 3.  Mossbauer spectroscopy revealed Fe(III) in all samples, whereas SB, CL and AZTD also contained appreciable Fe(II).  Spectra suggest that both Fe(II) and Fe(III) were substituted into aluminosilicates, although CL, AZTD and IS also contained Fe(III) oxide phases.  Total iron soly. measured after 24 h ranged between 4-16\% of the initial iron content for each material, but did not scale with either the sp. surface area or the total iron content of the samples.  Instead, we show that Fe(II)-contg. solid phases such as Fe(II)-substituted aluminosilicates represent a significant, and sometimes dominant, source of sol. Fe in acidic environments.  Results of dissoln. studies also show that the nature of the acid influences iron solubilization, as elevated concns. of nitrate encountered from nitric acid at pH 1 suppressed Fe(II) formation.  We propose a surface-mediated, non-photochem. redox reaction between nitrate and Fe(II), which may contribute to Fe(II)/Fe(III) cycling in the atm. [on SciFinder(R)]},
	keywords = {iron mineral dust source material acid mobilization},
	author = {Cwiertny, David M. and Baltrusaitis, Jonas and Hunter, Gordon J. and Laskin, Alexander and Scherer, Michelle M. and Grassian, Vicki H.}
}
@article {182,
	title = {Adsorption of sulfur dioxide on hematite and goethite particle surfaces.},
	journal = {Physical Chemistry Chemical Physics},
	volume = {9},
	year = {2007},
	note = {CAPLUS AN 2007:1196084(Journal)},
	month = {2007///},
	pages = {5542 - 5554},
	publisher = {Royal Society of Chemistry},
	abstract = {The adsorption of sulfur dioxide (SO2) on iron oxide particle surfaces at 296 K has been investigated using XPS.  A custom-designed XPS ultra-high vacuum chamber was coupled to an environmental reaction chamber so that the effects of adsorbed water and mol. oxygen on the reaction of SO2 with iron oxide surfaces could be followed at atmospherically relevant pressures.  In the absence of H2O and O2, exposure of hematite (α-Fe2O3) and goethite (α-FeOOH) to SO2 resulted predominantly in the formation of adsorbed sulfite (SO32-), although evidence for adsorbed sulfate (SO42-) was also found.  At satn., the coverage of adsorbed sulfur species was the same on both α-Fe2O3 and α-FeOOH as detd. from the S2p:Fe2p ratio.  Equivalent satn. coverages and product ratios of sulfite to sulfate were obsd. on these oxide surfaces in the presence of water vapor at pressures between 6 and 18 Torr, corresponding to 28 to 85\% relative humidity (RH), suggesting that water had no effect on the adsorption of SO2.  In contrast, mol. oxygen substantially influenced the interactions of SO2 with iron oxide surfaces, albeit to a much larger extent on α-Fe2O3 relative to α-FeOOH.  For α-Fe2O3, adsorption of SO2 in the presence of mol. oxygen resulted in the quant. formation of SO42- with no detectable SO32-.  Furthermore, mol. oxygen significantly enhanced the extent of SO2 uptake on α-Fe2O3, as indicated by the greater than two-fold increase in the S2p:Fe2p ratio.  Although SO2 uptake is still enhanced on α-Fe2O3 in the presence of mol. oxygen and water, the enhancement factor decreases with increasing RH.  In the case of α-FeOOH, there is an increase in the amt. of SO42- in the presence of mol. oxygen, however, the predominant surface species remained SO32- and there is no enhancement in SO2 uptake as measured by the S2p:Fe2p ratio.  A mechanism involving mol. oxygen activation on oxygen vacancy sites is proposed as a possible explanation for the non-photochem. oxidn. of sulfur dioxide on iron oxide surfaces.  The concn. of these sites depends on the exact environmental conditions of RH. [on SciFinder(R)]},
	keywords = {adsorption sulfur dioxide hematite goethite particle surface},
	isbn = {1463-9076},
	author = {Baltrusaitis, Jonas and Cwiertny, David M. and Grassian, Vicki H.}
}
@conference {183,
	title = {Chemical properties of oxide nanoparticles: surface adsorption studies from gas- and liquid-phase environments.},
	booktitle = {Synthesis, Properties, Applications of Oxide Nanomaterials},
	year = {2007},
	note = {CAPLUS AN 2007:1408672(Conference; General Review)},
	month = {2007///},
	pages = {335 - 351},
	publisher = {John Wiley \& Sons, Inc.},
	organization = {John Wiley \& Sons, Inc.},
	abstract = {A review.  This article is to describe the potential use of ATR-FTIR spectroscopy, which is somewhat unique in that surface adsorption can be investigated at both the nanoparticle oxide/gas and nanoparticle oxide/liq. interfaces.  The mol. nature of oxide nanoparticle surfaces will most likely be different in these two phases.  The quantification of surface adsorption as a function of size could be done with this technique under these different conditions.  The results should be revealing and may provide addnl. insight into the chem. properties of oxide nanoparticles. [on SciFinder(R)]},
	keywords = {review oxide nanoparticle surface adsorption ATR FTIR spectroscopy interface},
	author = {Pettibone, John M. and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {184,
	title = {FTIR spectroscopy combined with quantum chemical calculations to investigate adsorbed nitrate on aluminum oxide surfaces in the presence and absence of co-adsorbed water.},
	journal = {Physical Chemistry Chemical Physics},
	volume = {9},
	year = {2007},
	note = {CAPLUS AN 2007:1019734(Journal)},
	month = {2007///},
	pages = {4970 - 4980},
	publisher = {Royal Society of Chemistry},
	abstract = {Surface reactions of nitrogen oxides with aluminum oxide particles result in the formation of adsorbed nitrate.  Specifically, when α-Al2O3 and γ-Al2O3 particles are exposed to gas-phase NO2 and HNO3 adsorbed nitrate forms on the surface.  In this study, Fourier transform IR (FTIR) spectroscopy is combined with quantum chem. calcns. to further our understanding of the adsorbed nitrate product on aluminum oxide particle surfaces in the presence and absence of co-adsorbed water at 296 K.  FTIR spectra of adsorbed nitrate on α-Al2O3 and γ-Al2O3 particles are interpreted using calcd. vibrational frequencies of nitrate coordinated to binuclear Al oxide cluster models.  Comparison of the calcd. and exptl. vibrational frequencies of adsorbed nitrate establishes different modes of coordination (monodentate, bidentate and bridging) of the nitrate ion to the surface in the absence of adsorbed water.  In the presence of co-adsorbed water, the nitrate ion becomes fully solvated, as shown by a comparison of the exptl. nitrate IR spectra as a function of relative humidity with the calcd. nitrate vibrational frequencies for binuclear Al cluster compds. which contain both coordinated nitrate ions and water mols.  These calcns. also suggest that adsorbed water can displace nitrate from direct coordination to the surface, leading to an outer-sphere nitrate adsorption complex as well as an inner-sphere complex.  Furthermore, the relative humidity dependence of the spectra suggest that water does not evenly wet the surface even at high relative humidity, as there are open or bare surface sites where nitrate ions are not solvated.  Besides adsorbed monodendate, bidendate, bridging and solvated nitrate, the presence of ion bound nitrate ion, partially solvated nitrate, mol. nitric acid, hydronium ion and H3O+:NO3- ion pairs on the oxide surface are also discussed. [on SciFinder(R)]},
	keywords = {adsorption surface reaction nitrate alumina water coadsorption},
	isbn = {1463-9076},
	author = {Baltrusaitis, Jonas and Schuttlefield, Jennifer and Jensen, Jan H. and Grassian, Vicki H.}
}
@article {185,
	title = {Reactions of sulfur dioxide on calcium carbonate single crystal and particle surfaces at the adsorbed water carbonate interface.},
	journal = {Phys. Chem. Chem. Phys.Physical Chemistry Chemical Physics},
	volume = {9},
	year = {2007},
	note = {CAPLUS AN 2007:608637(Journal)},
	month = {2007///},
	pages = {3011 - 3024},
	publisher = {Royal Society of Chemistry},
	abstract = {Sulfur dioxide reactions with calcium carbonate interfaces at 296 K in the presence and absence of adsorbed water result in the formation of adsorbed sulfite and sulfate.  The extent of reaction is significantly enhanced, approx. five- to ten-fold for particulate and single crystal CaCO3 (calcite), resp., in the presence of adsorbed water between 30 and 85\% RH.  At. force microscopy following the reaction shows that adsorbed water facilitates surface reactivity by enhancing the mobility of surface ions, giving rise to the formation of nanometer sized product crystallites approx. 1 nm in height.  Simultaneous with the formation of these crystallites is pitting and etching of the underlying substrate, which occurs preferentially in the vicinity of monoat. surface steps.  In the absence of water, there is little pitting and no evidence for the formation of crystallites.  X-Ray photoelectron core and valence band spectra confirm the presence of two sulfur adsorbed species, SO2-3 and SO2-4, with nearly equal amts. of SO2-3 and SO2-4 in the absence of adsorbed water and approx. five times more SO2-3 relative to SO2-4 in the presence of adsorbed water.  From these data, it is proposed that the nanometer-sized crystallites are composed primarily of CaSO3. [on SciFinder(R)]},
	keywords = {reaction sulfur dioxide calcium carbonate single crystal adsorbed water},
	isbn = {1463-9076},
	author = {Baltrusaitis, Jonas and Usher, Courtney R. and Grassian, Vicki H.}
}
@article {187,
	title = {Spatially Resolved Product Formation in the Reaction of Formic Acid with Calcium Carbonate (101̅4): The Role of Step Density and Adsorbed Water-Assisted Ion Mobility.},
	journal = {Langmuir},
	volume = {23},
	year = {2007},
	note = {CAPLUS AN 2007:521222(Journal)},
	month = {2007},
	pages = {7039 - 7045},
	publisher = {American Chemical Society},
	abstract = {The reaction of calcium carbonate (101̅4) single-crystal surfaces with formic acid (HCOOH) vapor was investigated using at. force microscopy (AFM) and XPS.  AFM images indicate the reaction produces rather well-defined crystallites, preferentially at step edges and at distinct angles to one another and mirroring the rhombohedral structure of the calcite surface, while exposing unreacted carbonate surface.  The size and surface d. of the crystallites depend upon substrate step d., exposure time, and relative humidity.  XPS data confirmed the crystallite compn. as the expected calcium formate product.  The AFM images show erosion and pit formation of the calcite surface in the vicinity of the product crystallites, clearly providing the spatially resolved characterization of the source of Ca ions.  AFM expts. exploring the effects of water vapor on the reacted surface show that the calcium formate crystallites are mobile under conditions of high relative humidity, combining to form larger crystallites and nanometer-sized crystals with an orthorhombohedral habit consistent with the α form, as confirmed by X-ray diffraction.  The implications for the reactions described here are discussed. [on SciFinder(R)]},
	keywords = {step density ion mobility reaction formic acid calcium carbonate},
	isbn = {0743-7463},
	author = {Usher, Courtney R. and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {181,
	title = {A Spectroscopic Study of Atmospherically Relevant Concentrated Aqueous Nitrate Solutions.},
	journal = {J. Phys. Chem. AJournal of Physical Chemistry A},
	volume = {111},
	year = {2007},
	note = {CAPLUS AN 2007:8813(Journal)},
	month = {2007///},
	pages = {544 - 548},
	publisher = {American Chemical Society},
	abstract = {Concd. aq. NO3- aerosols are present in the earth atm. due to heterogeneous reactions of sea salt and mineral dust aerosol with NOx (e.g., NO2, NO3, HNO3, N2O5).  Since the water content of these aerosols depends on relative humidity (RH), the compn. and NO3- concn. also depends on RH.  Unlike the original aerosols, aq. NO3- aerosols are photochem. active at solar wavelengths.  To better understand the NO3- chromophore in concd. aq. NO3- aerosols, the attenuated total reflection-Fourier transform IR spectroscopic (ATR-FTIR) and UV/VIS spectra of concd. NO3- solns. were measured over a large concn. range.  Both ATR-FTIR and UV/VIS spectroscopy showed changes in NO3- spectra with increasing concn.  Ab-initio calcns. were used to aid in assigning and interpreting these spectra.  From these data, it was predicted that aq. NO3- aerosols photoreactivity will strongly depend on RH since the mol. and electronic structure of NO3- becomes increasingly perturbed from that of the isolated ion in highly concd. atmospherically-relevant solns. [on SciFinder(R)]},
	keywords = {attenuated total reflectance Fourier transform IR spectroscopy analysis, particulate air pollution nitrate aerosol spectroscopic assessment, sea salt mineral dust atm reaction nitrate aerosol formation, spectroscopic assessment atm relevant concd aq nitrate soln, UV visible spectroscopy atm nitrate aerosol analysis},
	isbn = {1089-5639},
	author = {Hudson, Paula K. and Schwarz, Jaclyn and Baltrusaitis, Jonas and Gibson, Elizabeth R. and Grassian, Vicki H.}
}
@article {188,
	title = {Surface Reactions of Carbon Dioxide at the Adsorbed Water-Oxide Interface.},
	journal = {J. Phys. Chem. CJournal of Physical Chemistry C},
	volume = {111},
	year = {2007},
	note = {CAPLUS AN 2007:1033025(Journal)},
	month = {2007///},
	pages = {14870 - 14880},
	publisher = {American Chemical Society},
	abstract = {In this study, FTIR spectroscopy is used to investigate surface reactions of carbon dioxide at the adsorbed water-oxide interface.  In particular, FTIR spectra following CO2 adsorption in the presence and absence of coadsorbed water on hydroxylated nanoparticulate Fe2O3 and γ-Al2O3 at 296 K are reported.  In the absence of coadsorbed water, CO2 reacts with surface O-H groups to form adsorbed bicarbonate on the surface.  In the presence of coadsorbed water, this reaction is blocked as water hydrogen bonds to the reactive M-OH sites.  Instead, CO2 reacts with adsorbed water to yield adsorbed carbonate and protonated surface hydroxyl groups, M-OH2+, through a proposed carbonic acid intermediate.  The carbonate spectra recorded between 10 and 90\% RH are nearly identical to that of carbonate adsorbed on these surfaces in the presence of the liq. water.  FTIR isotope studies show that there is extensive exchange between oxygen in adsorbed water and oxygen atoms in both adsorbed carbonate and gas-phase carbon dioxide.  On the basis of these exptl. results along with quantum chem. calcns., a mechanism is proposed for surface reactions of carbon dioxide at the adsorbed water-oxide interface. [on SciFinder(R)]},
	keywords = {surface reaction carbon dioxide adsorbed water oxide interface},
	isbn = {1932-7447},
	author = {Baltrusaitis, Jonas and Schuttlefield, Jennifer D. and Zeitler, Elizabeth and Jensen, Jan H. and Grassian, Vicki H.}
}
@article {189,
	title = {FTIR Spectroscopy Combined with Isotope Labeling and Quantum Chemical Calculations to Investigate Adsorbed Bicarbonate Formation Following Reaction of Carbon Dioxide with Surface Hydroxyl Groups on Fe2O3 and Al2O3.},
	journal = {Journal of Physical Chemistry B},
	volume = {110},
	year = {2006},
	note = {CAPLUS AN 2006:504389(Journal)},
	month = {2006///},
	pages = {12005 - 12016},
	publisher = {American Chemical Society},
	abstract = {FTIR spectroscopy combined with isotope labeling expts. and quantum chem. calcns. is used to investigate the adsorption of carbon dioxide on hydroxylated metal oxide surfaces.  In particular, transmission FTIR spectra following CO2 adsorption on hydroxylated nanoparticulate Fe2O3, α-Al2O3, and γ-Al2O3 particles at 296 K are reported.  As expected, reaction of CO2 with these surfaces results in the formation of adsorbed bicarbonate and carbonate.  In this study, the vibrational spectrum of the bicarbonate product is analyzed in detail through the use of isotope labeling expts. and quantum chem. calcns.  The exptl. and calcd. vibrational frequencies of adsorbed HC16O3-, DC16O3-, HC18O3-, HC16O18O2-, and HC18O16O2- indicate that bicarbonate bonds to the surface in a bridged structure.  There is some evidence from the mixed isotope expts. that following initial nucleophilic attack of OH, the formation of the final bicarbonate structure involves a proton transfer.  On the basis of energetic considerations, the proton transfer mechanism most likely occurs through an intermol. process involving either coadsorbed hydroxyl groups and/or carbonate. [on SciFinder(R)]},
	keywords = {adsorption carbon dioxide hydroxylated metal oxide surface chemisorption},
	isbn = {1520-6106},
	author = {Baltrusaitis, Jonas and Jensen, Jan H. and Grassian, Vicki H.}
}
@article {191,
	title = {Heterogeneous uptake and reactivity of formic acid on calcium carbonate particles: a Knudsen cell reactor, FTIR and SEM study.},
	journal = {Physical Chemistry Chemical Physics},
	volume = {7},
	year = {2005},
	note = {CAPLUS AN 2005:1066074(Journal)},
	month = {2005///},
	pages = {3587 - 3595},
	publisher = {Royal Society of Chemistry},
	abstract = {The heterogeneous uptake and reactivity of formic acid (HCOOH), a common gas-phase org. acid found in the environment, on calcium carbonate (CaCO3) particles have been investigated using a Knudsen cell reactor, Fourier transform IR (FTIR) spectroscopy and SEM.  FTIR measurements show that the adsorption of formic acid on the surface of calcium carbonate results in the formation of calcium formate.  Besides calcium formate, carbonic acid is also a reaction product under dry conditions (<1\% RH).  Under dry conditions and at low pressures, the initial uptake coeff. of formic acid on CaCO3 particles is measured to be 3 {\textpm} 1 {\texttimes} 10-3 and decreases as the surface sats. with adsorbed products.  The max. surface coverage of formic acid under dry conditions is detd. to be (3 {\textpm} 1) {\texttimes} 1014 mols. cm-2.  Under humidified conditions (RH >10\%), adsorbed water on the surface of the carbonate particles participates in the surface reactivity of these particles, which results in the enhanced uptake kinetics and extent of reaction of this org. acid on CaCO3 as well as opens up several new reaction pathways.  These reaction pathways include: (i) the water-assisted dissocn. of carbonic acid to CO2 and H2O and (ii) the formation of calcium formate islands and crystallites, as evident by SEM images.  The results presented here show that adsorbed water plays a potentially important role in the surface chem. of gas-phase org. acids on calcium carbonate particles. [on SciFinder(R)]},
	keywords = {adsorption chemisorption formic acid calcium carbonate particle},
	isbn = {1463-9076},
	author = {Al-Hosney, Hashim A. and Carlos-Cuellar, Sofia and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {192,
	title = {Surface reactions of carbon dioxide at the adsorbed water-iron oxide interface.},
	journal = {Journal of Physical Chemistry B},
	volume = {109},
	year = {2005},
	note = {CAPLUS AN 2005:466038(Journal)},
	month = {2005///},
	pages = {12227 - 12230},
	publisher = {American Chemical Society},
	abstract = {Despite the fact that CO2 is an abundant atm. gas with profound environmental implications, there is little information on the reaction of CO2 at the adsorbed water-oxide interface.  In this study, the chem. of CO2 at the adsorbed water-iron oxide interface was investigated with FTIR spectroscopy.  As shown here, the thin water layer on the iron oxide surface plays an important role in the surface chem. of CO2.  In particular, adsorbed water enhances CO2 uptake, undergoes isotope exchange with CO2 in O(18)-labeled expts., and influences the chem. nature of the predominant adsorbed product on the surface from bicarbonate to carbonate.  The resultant thin water film is acidic in nature from the reaction of CO2.  The IR spectrum recorded of adsorbed carbonate at the adsorbed water-iron oxide interface is remarkably similar to that at the bulk liq. water-iron oxide interface.  Since reactions in thin water films estd. to be ≈2 layers will play a role in a no. of environmental processes, it is essential to understand the chem. of these "wet" interfaces with atm. gases. [on SciFinder(R)]},
	keywords = {carbon dioxide surface reaction water adsorbate iron oxide},
	isbn = {1520-6106},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
