Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

You searched for id:"handle:10012/14981". One record found.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University of Waterloo

1. Daniels, Lindsey. The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications.

Degree: 2019, University of Waterloo

Nano-scale devices continue to challenge the theoretical understanding of microscopic systems. Of particular interest is the characterization of the interface electrochemistry of sensors, which operate as field effect transistors with graphene in contact with the solution. While plenty of experimental research has been conducted in regard to the viability and sensitivity of graphene-based devices, the understanding of the microscopic and macroscopic physics of these sensors has lagged, unlike any other areas of applications for graphene. Although some successful models of these sensors have been developed, relatively little theoretical work to account for the vast extent of experimental work. Typically operated in a regime of high ion concentration and high surface charge density, dielectric saturation, dielectric decrement, and ion crowding become non-negligible at the interface, complicating continuum treatments based upon the Poisson-Boltzmann equation. Modifications to the standard Poisson-Boltzmann theory are explored, with modifications due to dielectric saturation and dielectric decrement considered in tandem with a Bikerman-Friese model to account for the steric effects of ions. In the case of dielectric saturation, a model proposed by Booth is used to characterize the diffuse layer capacitance for both metallic and graphene electrodes immersed in an electrolyte. The dependence of the diffuse layer capacitance on the surface charge density of the electrode exhibits two peaks, in contrast to the experimental results. For dielectric decrement, a dielectric permittivity dependent on the concentration of positive and negative ions is used to determine the diffuse layer capacitance for both metallic and graphene electrodes. The diffuse layer capacitance shows a strong interplay between ion polarizability and steric effects, while exhibiting a single peak. A self-consistent and parameter-free method for the inclusion of a Stern layer is used in both cases, which eliminates the spurious secondary peak in the case of dielectric saturation and reduces the overall magnitude of the capacitance of the diffuse layer in both dielectric saturation and dielectric decrement. When a graphene electrode is used, the total capacitance in all modifications is dominated by V-shaped quantum capacitance of graphene at low potentials, which is a manifestation of the Dirac cone structure of the graphene π-electron bands. A broad peak develops in the total capacitance at high potentials, which is sensitive to the ion size at dielectric saturation, but is stable with dielectric decrement. In addition to the interactions of graphene with an electrolyte, considerable interest has recently been shown in studying the electric double layer that arises at the interface of doped graphene and a class of electrolytes known as ionic liquids. Ionic liquids are a class of molten ionic salts at room temperature that have low volatility and high ionic concentration, and are characterized by the overscreening and overcrowding effects…

Subjects/Keywords: Graphene; Differential Capacitance; Ionic Solutions; Sensing

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Daniels, L. (2019). The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/14981

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Daniels, Lindsey. “The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications.” 2019. Thesis, University of Waterloo. Accessed September 19, 2019. http://hdl.handle.net/10012/14981.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Daniels, Lindsey. “The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications.” 2019. Web. 19 Sep 2019.

Vancouver:

Daniels L. The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications. [Internet] [Thesis]. University of Waterloo; 2019. [cited 2019 Sep 19]. Available from: http://hdl.handle.net/10012/14981.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Daniels L. The Interactions of Graphene with Ionic Solutions and Their Effects on the Differential Capacitance for Sensing Applications. [Thesis]. University of Waterloo; 2019. Available from: http://hdl.handle.net/10012/14981

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.