Accession Number:

ADA504989

Title:

Carbon Nanotube Synthesis an Detection: Limiting the Environmental Impact of Novel Technologies

Descriptive Note:

Doctoral thesis

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

Report Date:

2009-06-01

Pagination or Media Count:

227.0

Abstract:

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.

Subject Categories:

  • Inorganic Chemistry
  • Refractory Fibers
  • Environmental Health and Safety

Distribution Statement:

APPROVED FOR PUBLIC RELEASE