Carbon nanotube synthesis and detection : limiting the environmental impact of novel technologies
Plata, Desiree L.
MetadataShow full item record
Driven by commercial promise, the carbon nanotube (CNT) industry is growing rapidly, yet little is known about the potential environmental impacts of these novel materials. In particular, there are no methods to detect CNTs in environmental matrices (e.g., sediment) and thus, there is no way to study their transport or gauge ecological exposure. Thermal methods were developed to quantify CNTs in coastal sediments down to 10 ug per sample, which is sufficient to for CNTs in laboratory air, but not sufficient to measure contemporary levels of CNTs in the environment (which were estimated to be present at pg g-1 sediment levels using a dynamic mass balance model). In addition to the CNTs themselves, potential impacts of CNT production were assessed by monitoring emissions from a representative synthesis. An ethene-fed chemical vapor deposition process generated several compounds of environmental concern, including the greenhouse gas, methane, the hazardous pollutants, benzene and 1,3-butadiene, and toxic polycyclic aromatic hydrocarbons. By identifying critical CNT precursors (alkynes), I delivered these compounds without thermal pre-treatment and achieved rapid CNT growth. This approach reduced carbonaceous emissions by more than an order of magnitude, and lowered initial feedstock requirements and energetic demands by at least 20%, without sacrificing CNT yield.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2009
Showing items related by title, author, creator and subject.
Sands and environmental conditions impact the abundance and persistence of the fecal indicator bacteria Enterococcus at recreational beaches Halliday, Elizabeth (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-09)The marine fecal indicator Enterococcus is measured at beaches to detect fecal contamination events, and beaches are closed to bathers when Enterococcus is found to exceed the federally mandated limit. This dissertation ...
The environmental impacts of boating : proceedings of a workshop held at Woods Hole Oceanographic Institution, Woods Hole MA USA, December 7 to 9, 1994 Crawford, Richard E.; Stolpe, Nils E.; Moore, Michael J. (Woods Hole Oceanographic Institution, 1998-03)Substantiated impacts of boating activity discussed at this workshop include: sediment and contaminant resuspension and resultant turbidity; laceration of aquatic vegetation with loss of faunal habitat and substrate ...
Green, Sarah A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-02)The work presented in this thesis consists of three parts. The first is a photophysical study of the mechanism of fluorescence quenching by stable nitroxyl radicals, which are becoming an important analytical tool for ...