| dc.contributor.author | Qiu, Liyan. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:25Z | |
| dc.date.available | 2000 | |
| dc.date.issued | 2000 | en_US |
| dc.identifier.other | AAINQ66643 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55771 | |
| dc.description | Thermal properties including heat capacity, thermal expansion, thermal conductivity and the Gruneisen parameter are fundamental characteristics of materials. They provide important information such as thermodynamic stability, anharmonicity of lattice vibrations, interatomic interactions and the utility of materials for various applications. | en_US |
| dc.description | The thesis is concerned with determination of thermal properties, especially low-temperature (below room temperature) heat capacities of some selected framework materials including zeolites, clathrates and a channel-forming diol. The determination of thermal properties of these novel materials has several purposes. First, these materials display various physical (e.g. thermal, electrical, optical) properties which can be tailored by doping with different guest molecules or atoms. Some are industrially important catalysts and others are possible thermoelectric materials for cooling devices and power generation. Secondly, thermodynamic properties such as DeltaG, Delta H and DeltaS are necessary to understand the stability and explore the applications of novel materials. Thermodynamic properties are especially important to design and synthesize new framework materials. Finally, heat capacities are required to understand thermal conductivity, which is indispensable to determine the utility and limitations of materials, especially thermoelectric materials. | en_US |
| dc.description | The heat capacities of three zeolites with different frameworks and compositions, NaA, NaX and NaY, were determined by adiabatic calorimetry; the complete thermodynamic properties below 300 K were determined and no solid-solid phase transitions were found in the experimental temperature range. A linear relationship between the Gibbs energy of formation and the Al/(Al + Si) molar ratio was found. These results show that thermodynamic stability of zeolites is enthalpic but not entropic. These findings are useful in the estimation of thermodynamic properties and synthesis of new zeolites. | en_US |
| dc.description | The heat capacities of five type I clathrates, Na8Si 46, Ba8Ga16Si30, Sr8Ga 16Ge30, Sr8Zn8Ge38 and Cs 8Ga8Sn38, were investigated. No solid-solid phase transitions were found between 30 and 300 K and the related thermodynamic properties were derived. Gruneisen parameters indicate that anharmonicity correlates with resonant scattering and the amorphous-like thermal conductivities of Si and Ge clathrates but the Sn clathrate shows strong host-guest interactions. | en_US |
| dc.description | The low-temperature heat capacity of a solvent-free diol, 2,6-dimethylbicyclo[3.3.1]nonane- exo-2, exo-6-diol was determined. The linear relationship between heat capacity and temperature shows the existence of many high-frequency modes. The high fusion entropy indicates that this chemical compound is an ordered molecular crystal rather than plastic crystal, likely due to strong hydrogen bonding. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2000. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Physical. | en_US |
| dc.title | Thermal properties of framework materials: Selected zeolites, clathrates and an organic diol. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
