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Increasing Production of Engineered Nanomaterials If you look at the consumer products that came out in the last 10 years, it’s not too difficult to see a dramatic increase in products that claim to contain nanoparticles. Nanotech becomes the “I wish” technology. I wish my tennis racquet to be stronger and lighter, my ipod would hold more # of songs…etc. The list is becoming longer and longer, among the current list of more than 500 consumer products that claim to include NPs, about 20% contain Ag-NPs. According to Christine…. After reading these #s, it won’t be too surprising to find nanoparticles in waters and wastewaters, which in fact, is the most probable human exposure route of Ag-NPs (10). Looking at this washer reminds me of Paul Westerhoff’s study on silver nanoparticles in socks Christine Hendren, Duke University

Egyptian Eye Makeup and Hair Dye (~ 2000 BC): Fabrication of quantum dots in your hair!! The composition and supramolecular organization of keratins can control PbS nanocrystal growth inside a hair Lead-based chemistry was initiated in ancient Egypt for cosmetic preparation more than 4000 years ago. Here, we study a hair-dyeing recipe using lead salts described in text since Greco-Roman times. We report direct evidence about the shape and distribution of PbS nanocrystals that form within the hair during blackening. It is remarkable that the composition and supramolecular organization of keratins can control PbS nanocrystal growth inside a hair. Nano Lett., 2006, 6 (10), pp 2215–2219 DOI: 10.1021/nl061493u Nano Lett., 2006, 6 (10), pp 2215–2219

Maya Blue Paint (2000 BC – AD 250): An hybrid organic-inorganic composite nanomaterial Resistance to acid and biocorrosion, color retention after centuries in the extreme conditions of the rain forest Science 273, 223 (1996)

The Lycurgus Cup (~ 4 AD): Most sophisticated glass objects before the modern era Most technically sophisticated glass objects produced before the modern era We started to hear the buzzword “nanotech” around the turn of the millennium, but the first use of nanoparticles can actually be dated all the way back to the 4th century AD. The Lycurgus Cup. In this silica-base glass, gold nanoparticles are dispersed throughout. When the cup is viewed in reflected light, it appears yellowish-green in color. When view with light coming through the glass (transmitted light), it appears ruby-red. In 1847, 162 yrs ago, Michael Faraday discovered that the optical properties of gold colloids differed from those of the corresponding bulk metal. In 1912, 97 yrs ago, The Braggs solved the first crystal structure In 1959, 50 yrs ago, Richard Feynman gave a speech to the American Physical Society entitled “There’s Plenty of Room at the Bottom”. His realization that “all things do not simply scale down in proportion” is now considered the hallmark of nanoscience NPs are silver-gold alloy, with a ratio of silver to gold of about 7:3, containing in addition about 10% copper. www.nanowerk.com/spotlight/

Nanotubes and nanowires in ancient Damascus blades (~900 AD) Multiwalled tubes, bent like a rope, with the characteristic layer distance d 0.34 nm Young’s modulus and tensile strength of CNT is about 10 and 20 times higher than that of steel Hard - It is claimed that a Damascus steel blade could cut a piece of silk in half as it fell to the ground Malleable – can be bent to 90 degree The smiths repeatedly heated and hammered (forging) the cake till it was stretched and flattened into a blade. During this process the wavy pattern was formed on the surface of the blade Nature 444, 286 (2006)

Nanoparticles are Ubiquitous in Water and Wastewater Source: Hochella et al., 2007 The Clark Fork River in Western Montana Hydrothermal Vent Mine Drainage Sediment Porewater

Drinking Water Distribution System Nanoparticles are Ubiquitous in Water and Wastewater Benn & Westerhoff, 2008 Environ. Sci. Technol., 2008, 42 (11), 4133–4139 Municipal Wastewater Kim et al., 2010 Environ. Sci. Technol. 44,19, 7509-7514 Sewage Sludge Hochella et al., 2007 J. Environ. Monit. 9, 1306-1316 Drinking Water Distribution System

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What do environmental researchers have to do with nano? Source Formation Stability Mobility Bioavailability Toxicity Receptor 1010

Physicochemical properties of nanoparticles that may influence biocompatibility.

Uncoated particles bind proteins and are taken up by the Reticuloendothelial System (RES) into the liver and spleen “PEGylated” particles bind very few proteins, avoid uptake by the RES, and are longer circulating in the blood The binding of certain apolipoproteins can be useful for distribution of particles across the blood brain barrier into the brain Source: Aggarwal et al., Advanced Drug Delivery Reviews, 61, 428-437, (2009)

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Levard et al., ES&T, 2012, 46 (13), pp 6900–6914

Kaegi et al. Environ. Sci. Technol. 2011, 45, 3902–3908. 17

Capped-Sulfidized AgNPs Capped AgNPs “Pristine” NanoComposix, Inc. Capped-Sulfidized AgNPs “Transformed” Levard et al., 2011 Floc particle 18

pH 7 5mM NaNO3

pH 7 5mM NaNO3

Nanoparticles as an unintended by-product Bioreduction of hexavalent uranium, U(VI), to tetravalent uranium, U(IV), which precipitates as uraninite. Assumption: the formation of highly insoluble uraninite (UO2) will inhibit the mobilization of uranium. So, we might ask the question: Are nanoparticles good or bad? I once gave a talk near Hollywood, CA and I gave it a title: Environmental colloids, the good, the bad, and the ugly. As much as I like Cline Eastwood, the talk was not about cowboy movies but the different roles of nanoparticles in the environment. Sometimes they are good, such as the ones that are used to clean up our water. Sometimes they are bad, viruses for example, they are nano in size, they make us sick. And sometimes, it’s hard to tell, and I called those “the Ugly” because they have the potential to turn bad. Take a look at this TEM picture (top right), this sulfate reducing bacteria (point to the area) is used in bioremediation to convert hexavalent uranium to tetravalent uranium. The assumption is that… However, these uraninite are very small in size, 1.5–2.5 nm, and you can see (point the area) the bacteria precipitates uraninate on their surfaces. So, are we really immobilizing uranium? Another example is the use of ZVI in PRB. PRB becomes popular in the last 15 years as low-cost, in-situ (versus expensive pump-and-treat) treatment of groundwater contaminated with chlorinated compounds, heavy metal, and radionuclides. ZVI as strong reductant. Unintentional release of colloidal iron oxide. Nanoscale ZVI encapsulated in an emulsion droplet. Source: Suzuki et al., 2002, Nature Zero-valent iron (ZVI) Permeable Reactive Barrier (PRB) Δ in chemical & biological gradient Source: oceanworld.tamu.edu/.../Images/schematic.gif

Electrons Mineral Cluster Bacterial Cells Human being Distant Galaxies Red Sea Sun 10-26 10-9 10-6 100 106 109 1026 Meters Contact Information https://blogs.umass.edu/borislau E-mail: borislau@engin.umass.edu 22

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Source: Andrew Maynard, Woodrow Wilson Center, Project on Emerging Nanotechnologies

Core composition, size, and shape Hydrodynamic diameter Are these two particles the same? Core composition, size, and shape Hydrodynamic diameter Ligand composition Ligand packing density Would you expect them to have the same fate and transport behaviors in the environment?

Big impact due to small difference on NP surface! Only the structured NPs penetrated the plasma membrane without bilayer disruption Core particle size (4.3 to 4.9 nm) and shape Ratio of hydrophilic to hydrophobic ligands (2:1) Ligand-shell packing density (11 to 15%) 4 deg C Trapped in endosomes = do not reach cytosol OT: detected in cells as a diffuse pattern Think of it as NPs with “antifouling” properties  avoid non-specific adsorption of proteins  better drug carriers Verma et al., Nature Materials 7, 588 - 595 (2008)

Zhong et al., 2006  Adv. Mater., 18, 2426 Industrial, medical, and environmental application Engineered and natural iron oxide nanoparticles in both natural and engineered aquatic systems They are responsible for important environmental processes such as soil genesis (16), biogeochemical element cycling (17), and contaminant transport (10, 12). Iron oxide nanoparticle adsorption on surfaces is associated with numerous applications and implications range from the design of nanomedicine (6, 7, 20) to environmental health and safety (21, 22). Hochella et al., 2007 J. Environ. Monit. 9, 1306-1316 Wen et al. 2005, J. Phys. Chem. B, 109, 215 - 220. Park et al., 2004 Nat. Mater. 3, 891-895

Size-Dependent Reactivity of Hematite Nanoparticles Hematite’s catalytic efficiency (surface area normalized rates) in Mn-oxidation reactions increases by 1 to 2 orders of magnitude when going from 37nm to 7nm in size Good contaminant scavenger with a significant increased sorption affinity for aqueous Cu2+ The hematite we are using in this study have been shown to have size-dependent reactivity Increase in Mn Oxidation – This may be due to the distortion of hematite surface binding sites, which in turn affects the local bonding of the adsorbing aqueous Mn ions This results in the rapid formation of Mn oxides that could serve as heavy metal adsorbents in water. Madden and Hochella, 2005. Geochim. Cosmochim. Acta, 69, 389-398 Madden et al., 2006. Geochim. Cosmochim. Acta, 70, 4095-4104

pH 6 10mM NaNO3 When interacting with fulvic acid-coated silica substrate, “pristine” AgNPs deposited faster (~ an order of magnitude) and more (~4 times as much deposited mass) than “transformed” AgNPs. This suggests that sulfidized AgNPs might be less susceptible to removal by granular media filtration. pH = 6, 10mM NaNO3 Figure 7 shows observable differences in adsorption dynamics between “pristine” and “transformed” AgNPs. After 24 hours of sulfidation using procedures described by Levard et al.1, the 50 nm PVP-capped AgNPs exhibited reduced adsorption kinetics and extent. When interacting with fulvic acid-coated silica substrate, “pristine” AgNPs adsorbed faster (almost an order of magnitude) and more (~4 times as much adsorbed mass) than “transformed” AgNPs. This preliminary finding suggests that sulfidized AgNPs might be less susceptible to removal by granular media filtration. It also supports our hypotheses that these two types of AgNPs (capped versus capped-sulfidized) may interact differently with NOM (Hypothesis #1), resulting in differences in their immobilization by the substrate/collector surface (Hypotheses #2&3). The AgNPs were sulfidized using a 1mM sodium sulfide (Na2S) solution for 24 hours, the final solutions were centrifuged, washed, and resuspended 32

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