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Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems./
Author:	Feicht, Sarah E.
Description:	1 online resource (158 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.
Contained By:	Dissertation Abstracts International78-05B(E).
Subject:	Chemical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9781369414684

Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems.
Feicht, Sarah E.

Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems. - 1 online resource (158 pages)

Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

This item is not available from ProQuest Dissertations & Theses.

We apply mathematical methods to model diffusion and migration of ions, electrons, and holes in electrochemical and polymer semiconductor systems. When a voltage is applied across planar, blocking parallel electrodes, charge carriers redistribute in the cell to screen the electrode charge, forming electrical double layers. The structure of the double layer and the external current can be predicted via the Poisson-Nernst-Planck (PNP) equations for charge carrier flux, conservation, and electric potential. In this thesis, we employ asymptotic analysis and numerical methods to quantify charge transport in four separate electrochemical devices. In organic light-emitting diodes (OLEDs), diffusion in the disordered polymer semiconductor is significant in comparison to migration. We solve the PNP equations via asymptotic analysis and find that including diffusion leads to a large increase in current proportional to the ratio of the cell width to the double layer width, thus diffusion cannot be neglected. Mixed ionic-electronic conductors (MIECs) conduct both ions and electrons, however ion mobility is difficult to measure. We derive a similarity solution to the PNP equations for cation invasion in a planar MIEC polymer film, and find that the location of the moving front is proportional to the square-root of the product of ion mobility, applied voltage and time. However differences between these results and experimental data indicate that additional work is needed to verify the accuracy of this method to calculate ion mobility.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369414684Subjects--Topical Terms:

555952
Chemical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems.
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100 1 $a Feicht, Sarah E. $3 1182242
245 1 0 $a Mathematical Modeling of Ionic and Electronic Charge Transport in Electrochemical Systems.
264 0 $c 2016
300 $a 1 online resource (158 pages)
336 $a text $b txt $2 rdacontent
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500 $a Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.
500 $a Adviser: Aditya Khair.
502 $a Thesis (Ph.D.) $c Carnegie Mellon University $d 2016.
504 $a Includes bibliographical references
506 $a This item is not available from ProQuest Dissertations & Theses.
520 $a We apply mathematical methods to model diffusion and migration of ions, electrons, and holes in electrochemical and polymer semiconductor systems. When a voltage is applied across planar, blocking parallel electrodes, charge carriers redistribute in the cell to screen the electrode charge, forming electrical double layers. The structure of the double layer and the external current can be predicted via the Poisson-Nernst-Planck (PNP) equations for charge carrier flux, conservation, and electric potential. In this thesis, we employ asymptotic analysis and numerical methods to quantify charge transport in four separate electrochemical devices. In organic light-emitting diodes (OLEDs), diffusion in the disordered polymer semiconductor is significant in comparison to migration. We solve the PNP equations via asymptotic analysis and find that including diffusion leads to a large increase in current proportional to the ratio of the cell width to the double layer width, thus diffusion cannot be neglected. Mixed ionic-electronic conductors (MIECs) conduct both ions and electrons, however ion mobility is difficult to measure. We derive a similarity solution to the PNP equations for cation invasion in a planar MIEC polymer film, and find that the location of the moving front is proportional to the square-root of the product of ion mobility, applied voltage and time. However differences between these results and experimental data indicate that additional work is needed to verify the accuracy of this method to calculate ion mobility.
520 $a The net charge in a zwitterionic hydrogel is dependent on the surrounding electrolyte pH. This charge alters the electrical impedance of the hydrogel. We apply the PNP equations coupled with acid-base dissociation equations to predict the reduction in electrical impedance as pH deviates from the isoelectric point based on material parameters. This model aids in the design of low-impedance hydrogels to improve signal transmittance in biosensor encapsulation applications. Lastly, we model discharging of an electrolytic cell. At high voltage, a "reverse peak" or maximum in the current magnitude emerges. Through asymptotic analysis and numerical solutions of the PNP equations, we conclude that bulk depletion and neutral salt adsorption in the double layer during charging cause the reverse peak.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Chemical engineering. $3 555952
655 7 $a Electronic books. $2 local $3 554714
690 $a 0542
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Carnegie Mellon University. $b Chemical Engineering. $3 1182243
773 0 $t Dissertation Abstracts International $g 78-05B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10297429 $z click for full text (PQDT)