| Título: | The dielectric constants of cellulose and of water sorbed thereon. |
| Autores: | Brown, Douglas Frederick. |
| Fecha: | 1940 |
| Publicador: | McGill University - MCGILL |
| Fuente: |
 |
| Tipo: | Electronic Thesis or Dissertation |
| Tema: | Chemistry. |
| Descripción: | It has been found that increase in bursting strength of paper is accompanied by a decrease in the dielectric constant of that paper. This is true whether the strength is increased by pressure on the wet sheet or by beater treatment. Two explanations have been made for this relationship, an increase of fibre-to-fibre bonds and increased flatness of the fibres with increased strength. It has not been possible to separate these two effects. The anisotropy of cellulose as a dielectric has been established and a method devised whereby the axial and transverse values of the dielectric constant of the cellulose fibril could be measured. [...] These results have been interpreted in terms of the relative freedom of groups on the cellulose chain and it has been suggested that absorption and dispersion in cellulose· is probably due to displacement of hydroxyl groups restrained by secondary and coordinate valence forces rather than to rotation of glucose anhydride rings. A dielectric value versus water content curve has been obtained and found to agree with previous measurements. This curve definitely shows that the first water sorbed on cellulose is strongly held and has a low dielectric constant. Attempts to calculate the dielectric constant of the sorbed water from the dielectric values have shown the impossibility of such calculations on the basis of present knowledge. |
| Idioma: | en |
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