dc.contributor.author |
Tuffery, Denis E |
|
dc.date.accessioned |
2011-03-16T23:41:44Z |
|
dc.date.accessioned |
2022-10-25T06:19:38Z |
|
dc.date.available |
2011-03-16T23:41:44Z |
|
dc.date.available |
2022-10-25T06:19:38Z |
|
dc.date.copyright |
1969 |
|
dc.date.issued |
1969 |
|
dc.identifier.uri |
https://ir.wgtn.ac.nz/handle/123456789/23406 |
|
dc.description.abstract |
Asymmetric potentials are produced on heating a kaolinite sample held between platinum electrodes. Under vacuum the potentials rise to a peak of about 500 mV at about 500°C and under atmospheric pressure a peak of about 120 mV at about 600°C. The potential peak at 500°C is reproduced at about 575°C on cooling and reheating under vacuum conditions. The potential peak is dependent on heating rate to a marked degree; a slower heating rate of around 5°C/min produced no peak at 500 - 700°C but did produce a peak that is stable for a week at 800°C of about 800 mV. while a faster rate of around 30° C/min introduces further peaks.
The potentials under vacuum at a heating rate of 10°C/min are shown to agree well with a calculated curve based on dehydroxylation of material at one electrode in preference to the material at the other electrode, such that where E is the potential produced, U is the heat of transport for the conducting species plus the heat of formation of a defect, F is the Faraday constant,ρ and σ are the density and thermal conductivity of the material, ΔH is the enthalpy of the reaction,Ap and Ep are the Arrhenius parameters R is the gas constant and α is the fraction of material which has reacted. The other potential curves are interpreted in terms of this equation. A study of oxygen loss from a metakaolinite sample was negative. |
en_NZ |
dc.format |
pdf |
en_NZ |
dc.language |
en_NZ |
|
dc.language.iso |
en_NZ |
|
dc.publisher |
Te Herenga Waka—Victoria University of Wellington |
en_NZ |
dc.title |
Electrical properties of kaolinite |
en_NZ |
dc.type |
Text |
en_NZ |
vuwschema.type.vuw |
Awarded Research Masters Thesis |
en_NZ |
thesis.degree.discipline |
Chemistry |
en_NZ |
thesis.degree.grantor |
Te Herenga Waka—Victoria University of Wellington |
en_NZ |
thesis.degree.level |
Masters |
en_NZ |
thesis.degree.name |
Master of Science |
en_NZ |