Theory Of The Dielectric Constant Of Polar Liquids
Open Access
- Author:
- Tang, Qishun
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Ralph H Colby, Thesis Supervisor
Dr. Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- dielectric constant
polar liquids
theory - Abstract:
- I study the dielectric constant of highly polar liquids, such as ionic liquids (ILs) and polymerized ionic liquids (PILs). ILs and PILs have wide applications in fields like electrolytes in lithium ion batteries, fuel cell-membrane, electrode assemblies, supercapacitors, sensors and actuators. To understand the dielectric properties of ILs and PILs is of both scientific and practical importance. Nevertheless, Onsager’s theory applicable to common polar systems is not applicable in IL and PIL systems with huge permanent dipole moments, for which an additional correlation g factor, originally introduced by Kirkwood should be incorporated, which specifies the short range interaction among dipoles. It is noted that in highly polar liquids the g factor decreases rapidly as the density of strong dipoles increases, making the dielectric constant also decrease as the dipole density increases. This trend is opposite to the prediction of Onsager’s theory which expects the dielectric constant to increase as the density of the polar content increases. This thesis reviews all the classical models about the dielectric constant and recognizes the assumptions and limits of those models. I will propose some possible theories to explain the deviation from Onsager’s Theory in highly polar liquids.