Date of Award
2008
Degree Type
Thesis
Degree Name
Master of Science
Program
Chemistry
Supervisor
Dr. Yining Huang
Second Advisor
Dr. Zhifeng Ding
Third Advisor
Dr. Brian Pagenkopf
Abstract
The phase transitions of naphthalene and its 2-substituted methyl, methoxy, and chloro derivatives confined in mesoporous silicas were investigated by differential scanning calorimetry. A depression of phase transition temperature was observed. A comparison of the naphthalene in spherical and cylindrical pore systems was made, and the effect of molecular properties on the phase transition depression of the four compounds was investigated. It was found that depression and freeze-melt hysteresis is generally greater in spherical pores, and that electronic and size effects are contributing factors to transition temperature depression. Using powder X-ray diffraction it was found that while the crystal structure of confined naphthalene is the same as the bulk, there is a lattice expansion of the crystal. Furthermore, using differential scanning calorimetry and Raman spectroscopy it was shown on both a thermodynamic and molecular level that there is a non-freezing layer on the pore walls for each confined compound.
Recommended Citation
Lee, Janice Amabel, "Phase Transitions of Naphthalene and Naphthalene Derivatives Confined in Mesoporous Silicas" (2008). Digitized Theses. 4782.
https://ir.lib.uwo.ca/digitizedtheses/4782