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CEINT Research Projects

CEINT_Nanomaterial_Transport

Transport of Coated Nanomaterials
(PDF with full project description and images)

Lead Investigator: E.M. Hotze
Collaborators: Shihong Lin, Soryong Chae, and Mark Wiesner
PI: Greg Lowry
Carnegie Mellon University and Duke University

Reason for Research
Nanomaterials released in the environment, even if they are released in bare form, will rapidly be coated by macromolecules in the surrounding environment. Understanding if the effect of coatings on transport varies only based on coating type (i.e., coatings control transport) or varies depending on the coating and the underlying particle is key to anticipating their transport in the environment.

Effects of Polymer and NOM Coatings on Bactericidal Properties of NZVI
(PDF with full project description and images)

Lead Investigator: Zhiqiang (Eric) Li
Collaborators: N/A
PI: Kelvin Gregory and Greg Lowry
Carnegie Mellon University

Reason for Research
Nanoscale zero-valent iron (NZVI) particles that are used in aquifer remediation may come in contact with subsurface bacteria, and may adversely affect subsurface bacteria. Studies showed that Nanoscale zero-valent iron (NZVI), used in aquifer remediation, is toxic toward E. coli at concentrations as low as a few mg/L. However, NZVI particles used in remediation are coated with polymers or natural organic matter (NOM). It is important to understand how these surface coatings may affect the bactericidal properties of NZVI.

Transformation of Nanoparticles in the Atmosphere
(PDF with full project description and images)

Lead Investigator: Erica R. Trump
Collaborators: N/A
PI: Neil Donahue
Carnegie Mellon University

Reason for Research
To understand how the atmosphere modifies nanoparticle properties and how atmospheric processes control the deposition of nanoparticles to ecosystems.

Redox Transformations of Ag NPs in the Environment
(PDF with full project description and images)

Lead Investigator: Rui Ma
Collaborators: Brian Reinsch, Eric Li
PI: Greg Lowry
Carnegie Mellon University

Reason for Research
My research focuses on transformation and reactivity of nanoparticles. One project of mine is to investigate oxidative dissolution of silver nanoparticles. Silver nanoparticles (Ag NPs) are wildly used in consumer products because their bactericidal effects. Inevitably, the Ag NPs enter environment and pose a potential risk on human and other species. This research will help us to understand fate and transformation of nanoparticles (Theme 1) and will also provide useful information for Theme 2 and 3.

Macromolecule Adsorption to Silver Nanoparticles
(PDF with full project description and images)

Lead Investigator: Caitlin M. Trombly
Collaborators: N/A
PI: Robert D. Tilton
Carnegie Mellon University

Reason for Research
Nanomaterials released into the environment will ultimately interact with a variety of organic macromolecules, which may adsorb to the surface of the particles. This surface coating will impart new properties to the nanoparticles that may significantly impact their stability, bioavailability, mobility, and persistence. Thus, a thorough understanding of the chemical and biological transformations that the nanoparticles will undergo in the environment is necessary in order to predict their behavior within ecosystems.

Developing an Empirical Model for Estimating Attachment of Nano- and Submicron-particles Coated with Organic Macromolecules in Porous Media
(PDF with full project description and images)

Lead Investigator: Tanapon Phenrat
Collaborators: Jee Eun Song, Charlotte M. Cisneros, Daniel P. Schoenfelder, and Robert D. Tilton
PI: Greg Lowry
Carnegie Mellon University

Reason for Research
The fate and transport of manufactured nanoparticles (NPs) released into the environment is of great interest due to their increasing use in consumer products and their potential risks to the environment and human health. Most NPs are manufactured with a surface coating such as polymers or polyelectrolytes to provide specific functionality. Nanoparticles can also acquire a natural coating once released into the environment due to adsorption of natural organic matter (NOM) including humic and fulvic acids. Several recent studies indicate the need for mechanistic understanding of the effect of adsorbed engineered and natural macromolecules on nanoparticle transport (i.e. attachment efficiency, a) in porous media. It is unsure if existing empirical models capable of predicting a of electrostatically stabilized (bare) particles can predict a of NPs coated with organic macromolecules.

Heteroaggregation of Nanoparticles
(PDF with full project description and images)

Lead Investigator: Bundhit Chucherdwatanasak
Collaborators: N/A
PI: Greg Lowry
Carnegie Mellon University

Reason for Research
At present, nanoparticles have been used in many commercial products. However, once nanoparticles are released to the environment, i.e. groundwater, or sediment, no any estimation could be done to quantify the amount of nanoparticles on each phase: water, mineral surfaces, and organic matters. Understanding the influence of environmental conditions; pH, and ionic strength, surface chemistry of nanoparticles on heteroaggregation of nanoparticles could lead to the prediction the fate and transportation of nanoparticles in the complex system.

Impact of Morphology on Coated Nanoparticle Transport
(PDF with full project description and images)

Lead Investigator: Stacey Louie
Collaborators: N/A
PI: Greg Lowry
Carnegie Mellon University

Reason for Research
Engineered nanomaterials are often coated with macromolecules for various properties such as stability. Nanomaterials may also be coated with natural organic matter when released into the environment. Depending on the properties of the nanoparticle and coating, various morphologies can be produced. Understanding the effect of these morphologies on nanoparticle deposition is necessary to predict the transport of nanoparticles in the environment, and hence their distribution, exposure risk, and bioavailability.

Interactions between Silver Nanoparticles and Bacterial Biofilms
(PDF with full project description and images)

Lead Investigator: Stacy M. Pustulka
Collaborators: N/A
PI: Robert Tilton
Carnegie Mellon University

Reason for Research
Biofilms - adherent communities of bacteria surrounded by a matrix of extracellular polymeric substance (EPS) - are the prevailing microbial lifestyle in the environment. Nanoparticles, including antimicrobial silver nanoparticles, released into the environment will likely encounter biofilms. Interactions between the nanoparticles and biofilms will likely affect surface properties and transport of the nanoparticles, as well as biofilm viability.