Meng Zhao

Abstract

It has been proposed that the function of lithium ion batteries, fuel cells, capacitors, solar cells and actuators might be improved if membranes impregnated with organic salt solutions or conventional ionic liquids were replaced by film-forming ionic liquid polymers like those derived from 4-vinylimidazolium (4-VIm+) salts. 4-VIm+ polymers with a methyl substituent at the 2-position of the imidazole ring may have greater chemical and electrochemical stability than poly(ionic liquids), PILs, derived from 1-vinyl- and 4-VIm+ polymers with a hydrogen at the 2-position of the imidazole ring. The utility of PILs, in capacitive devices, however, is limited by poor ion mobility caused by incorporation of anionic and/or cationic components in the polymer chain. The ionic conductivity of PILs can be improved by lowering the glass transition temperature and/or reducing the dimensions of the ion-conductive phase. In the present research, 4-VIm+-based PILs were designed and synthesized with six different anions. The effect of anions of differing kind on the thermal properties of these polymers was evaluated and dielectric characteristics of 4-vinyl- and 1-vinylimidazolium polymer salts were compared. The glass transition temperature of the PF6− and trifluoromethylsulfonylimide, TFSI−, salts of polymers derived from1-butyl-2,3-dimethyl-4-vinylimidazolium (23D4VIm+) triflate polymers were found to be anomalous (substantially invariant) as compared to those of PF6−, TFSI−, and triflate salts of 4-vinyl- and 1-vinylimidazolium polymers. The invariance in the glass transition of poly(23D4VIm+) with different anions was attributed to increased separation between ion pairs, enforced by having substituents on the 1, 2, 3, and 4 positions of the imidazolium ring.

Library of Congress Subject Headings

Conducting polymers--Testing; Actuators--Materials; Ionic solutions; Plastic films--Electric properties

Publication Date

12-2014

Document Type

Dissertation

Student Type

Graduate

Degree Name

Microsystems Engineering (Ph.D.)

Department, Program, or Center

Microsystems Engineering (KGCOE)

Advisor

Thomas W. Smith

Advisor/Committee Member

Christopher J Collison

Advisor/Committee Member

Seth M Hubbard

Comments

Physical copy available from RIT's Wallace Library at QD382.C66 Z42 2014

Campus

RIT – Main Campus

Plan Codes

MCSE-PHD

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