Effects of Pressure on the Rotational Phase Transitions and Dielectric Properties of Solid Cyclopentanol

Author

David Nason Glidden

Publication Date

12-9-1972

Abstract

The dielectric constant and loss for solid cyclopentanol have been measured at hydrostatic pressures up to 2.5 Kbar for frequencies of 1 KHz to 5 MHz from 258 °K to 200 °K. Activation parameters have been calculated from the experimental data. In addition, activation parameters have also been calcuated from a fluctuation-barrier model for dipole reorientation and compare favorably with the experimental quantities. The dielectric constant shows that the phase transition from form I, with sperically symetric orientational freedom, to form II, with restricted orientational freedom, is readily brought about at these pressures. This phase transition was elucidated by an order­disorder model using the dielectric constant as the long range ordering parameter. Phase transitions from the rotational forms II and II’ to the nonrotational phase were also found to occur under pressure. Pressure was also found to effect the amount of association in phases II and II’. It is thought that the pressure removes the microscopic voids in the sample and increases the ability of the weak forces among the molecules to increase the association.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

John Root Green

Second Committee Member

Howard Carnes Bryant

Third Committee Member

Roy Thomas

Language

English

Document Type

Dissertation

Recommended Citation

Glidden, David Nason. "Effects of Pressure on the Rotational Phase Transitions and Dielectric Properties of Solid Cyclopentanol." (1972). https://digitalrepository.unm.edu/phyc_etds/354