Library Open Repository

A study of nanoparticles : silica fume and woodsmoke

Downloads

Downloads per month over past year

Cunningham, Elizabeth Ann (2003) A study of nanoparticles : silica fume and woodsmoke. PhD thesis, University of Tasmania.

[img] PDF (Whole thesis)
whole_Cunningha...pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

The research studies described herein were undertaken in order to
characterize the particulate matter comprising the inorganic pollutant silica
fume emitted by an electrometallurgical process and the organic emission of
woodsmoke from residential woodheaters. These two emissions were
selected in view of their suspected influential contribution to air pollution
in Hobart, Tasmania, Australia. Their size characterization was seen as a
necessary step for a better understanding of the nature of their toxicity
within the human respiratory system.
Their sizing was carried out using a Transmission Electron Microscope, the
primary particle size (CMD) for 'silica fume being found to vary from a
minimum• of 34nm (0.034µm) to a maximum of 500nm (0.050µm)
depending on sampling site at the smelter, while the aggregate size (VMD)
varied from a minimum of 124nm (0.124µm) to a maximum of 180nm
(0.18µm). Some 16,593 particles were involved. Sizes such as these place the
primary particles of silica fume within the definition of nanometre particles.
Similar results for the primary particles of silica fume have been recorded by
other workers in the field when the technique of electron microscopy has
been used.
On the other hand, woodsmoke organics was shown to vary in primary
particle size from a minimum CMD of 21nm (0.021µm) to a maximum of
23.5nm (0.023µm), depending on wood and heater type, while the aggregate
size varied from a minimum VMD of 35nm (0.035µm) to a maximum of
58n (0.058µm). Similar sizes were found with a woodsmoke contaminated ambient air sample, with CMD for primary particles of 16run (0.016µm) and
VMD for aggregates of 45nin (0.045µm). The woodsmoke sizing represented
the analysis of some 10,194 particles and permits both the primary particles
and almost all aggregates of woodsmoke to be defined as nanoparticles. This
was in contrast to previous work in the field which was at least a factor of
ten larger than the present study for both primary particles and aggregates, a
fact which has raised come concern with regard to sizing limitations.
Recent research has demonstrated the peculiarly high toxicity of particles in
the nanometre size range. Other recent published work has postulated that
this might explain the phenomena of health effects of nanoparticles on the
human cardiopulmonary systems. It would seem, therefore, plausible to
expect that the primary particles of silica fume and both the primary particles
and aggregates of woodsmoke may subscribe to such hypotheses, being
considered to be classified with the primary mediators of cardiopulmonary
mortality and morbidity.

Item Type: Thesis (PhD)
Keywords: Silica fume, Wood, Air, Nanoparticles
Copyright Holders: The Author
Copyright Information:

Copyright 2003 the Author – The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s).

Additional Information:

Thesis (Ph.D.)--University of Tasmania, 2003. Includes bibliographical references

Date Deposited: 09 Dec 2014 00:08
Last Modified: 11 Mar 2016 05:54
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page