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Qilin's Research Group
Civil and Environmental Engineering
Rice University
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Research

 
Environmental Fate, Transport and Toxicity of Engineered Nano-materials

Projects:

1. The Environmental Chemistry of Nanoscale Carbon

  • The objective of this project is to investigate the potential chemical transformation of carbon based nanomaterials (fullerene and carbon nanotubes) in the natural environment. Of particular focus is the photochemical oxidation that may occur in natural aqueous environment. In addition, the impacts the transformations have on subsequent transport process as well as the bioavailability and toxicity is being also evaluated.

    Photochemical transformation of aqueous nC60 particles.
    (Hwang and Li, Environ. Sci. Technol. 2010)

  • Funding source: NSF Center for Biological and Environmental Nanotechnology

2. Molecular basis for nanoparticle toxicity in the yeast Saccharomyces cerevisiae

  • The objective of this proposal is to use a genomics approach to identify genes and functions that are protective against toxicity caused by carbon fullerenes in a well-developed and experimentally-tractable model organism, the yeast Saccharomyces cerevisiae. A commercially available library ofapproximately 4,800 yeast deletant mutants will be systematically screened for sensitivity and resistance to carbon fullerenes. Physicochemical properties including particle size, shape, surface charge, specific surface area, and surface functionality of fullerene nanoparticles will be measured and correlated with toxicity. Genes missing in mutants found to exhibit sensitivity or resistance relative to wild-type cells will presumably encode functions that normally provide protection or cause sensitivity.
  • Collaborator: Dr. Alan Bakalinky, Oregon State University

3. Interactions of Natural Organic Matter with C60 Fullerene and their Impact on C60 Transport, Bioavailability and Toxicity

  • The project investigates the effect of NOM-C60 interactions on three key aspects of aqueous C60 nanoparticle (nC60) environmental behavior: 1) nC60 dispersion, physicochemical properties, and photochemical transformation; 2) Mechanisms and kinetics of aggregation and partition/deposition of nC60; 3) Molecular level mechanisms of nC60 toxicity to bacteria.

    TEM imaging of nC60 without NOM and with 20 mg/L SRFA
    ?(Xie et al., Environ. Sci. Technol. 2008)

    Kinetics of C60 fullerene dispersion in water enhanced by NOM and sunlight
    (Li et al., Environ. Sci. Technol. 2009)

    Humic acid attenuated the toxicity of nC60 to bacteria
    (Li et al. Environ. Toxicol. Chem. 2008)

  • Collaborator: Dr. Pedro Alvarez, Rice University
  • Funding source: EPA STAR

4. Monitoring Engineered Nanoparticles in the Environment

  • To identify release points, assess fate, and monitor exposure, we need reliable methods for detecting and quantifying engineered carbon nanomaterials (ECNs) in the environment. However, quantitative extraction and separation of ECNs from environmental sample is extremely difficult. Additionally, ECNs are indistinguishable from graphitic carbon ubiquitous in the environment in regions of the electromagnetic spectrum probed by modern spectroscopy, including absorption, fluorescence, scattering (at UV, IR, and X-ray wavelengths), and NMR. We use a novel approach based upon a unique molecular signature of ECNs ĘC zero mass defect. The detection is enabled by atmospheric pressure photoionization (APPI) coupled with ultrahigh resolution ion cyclotron resonance mass spectrometer. We were able to detect trace concentration of molecular C60 in the presence of aquatic natural organic matter.
  • Colaborator: Drs. William Hockaday and Carrie Masiello, Rice University
  • Funding source: NSF Center for Biological and Environmental Nanotechnology, Shell Center for Sustainability
 

 

 
 
--Contact Us

-----Rice University
-----6100 Main ST MS-519
-----213 Keck Hall
-----Houston TX 77005

-----Email: Qilin.li@rice.edu
-----Phone: (713) 348-2046
-----Office: Keck Hall 225

 

 
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-- Qilin's Research Group, 6100 Main ST MS-519, Houston, TX 77005 --