| dc.contributor.author | Michalski, Dariusz. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:05Z | |
| dc.date.available | 1995 | |
| dc.date.issued | 1995 | en_US |
| dc.identifier.other | AAINN05218 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55038 | |
| dc.description | Clathrates are lattice inclusion compounds in which one type of molecule forms a framework, called a host lattice, with lacunae in which the other kinds of molecules, called guests, reside. Clathrates are crystals, but long-range structural order does not seem to be sufficient to provide typical thermal behaviour. Their thermal conductivity is low and its temperature profile is unusual compared to other crystals. The origin of that unusual behaviour is the main subject of this research. | en_US |
| dc.description | A new group of clathrates was synthesized in the mid-1970's. The idea for their structure came from the dimensional and geometrical similarity of the hydrogen-bonded hexamer unit, as in Dianin's compound and related systems, with hexa-substituted benzene. This thesis concerns the study of thermal and related properties of systems based on hexakisphenylthiobenzene (HPTB), the archetypal compound in this series and the thermal conductivity of the CCl$\sb4$ clathrate of Dianin's compound, which is an example of its structural model. Since thermal and mechanical properties are determined by intermolecular forces, these systems afforded an opportunity to investigate the intermolecular interaction between guest and host molecules, the dynamics of molecular clusters and its effect on physical properties, and the role of concentration and type of guest species on thermal behaviour. | en_US |
| dc.description | Crystal structure (X-ray diffraction), thermal expansion (neutron powder diffraction), heat capacity (adiabatic calorimetry), elastic properties (Brillouin scattering) and thermal conductivity (steady-state method) were determined. Pertinent parameters were derived to shed light on the anharmonicity of molecular interactions and dynamics of the crystal lattice. Thermal behaviour was modelled. The resonant-scattering of acoustic phonons from localized modes brought about by dynamical disorder of the crystalline structure was identified as the primary source of the highly efficient thermal resistant mechanism. | en_US |
| dc.description | In addition the heat capacity of pure CBr$\sb4$ was measured and analyzed. This was required to delineate thermal effects in the investigation of the CBr$\sb4$ clathrate of HPTB. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1995. | 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 selected clathrates. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
