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Self-generated diffusiophoresis in d...

Kar, Abhishek.

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Self-generated diffusiophoresis in dead-end pores.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Self-generated diffusiophoresis in dead-end pores./
Author:	Kar, Abhishek.
Description:	188 p.
Notes:	Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.
Contained By:	Dissertation Abstracts International76-12B(E).
Subject:	Chemical engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3715523
ISBN:	9781321937572

Self-generated diffusiophoresis in dead-end pores.
Kar, Abhishek.

Self-generated diffusiophoresis in dead-end pores. - 188 p.

Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.

Thesis (Ph.D.)--The Pennsylvania State University, 2015.

Dead-end pores are ubiquitous in nature, from extracellular matrix in the brain to fractured porous media present in oil reserves. In many cases one would gain great advantage to be able to design transport in these dead-end pores. However, achieving fluid flows in dead-end pores is not possible through conventional pressure-driven mechanisms. Traditional electrokinetic flows produced by inserting electrodes are also impractical, especially when these pores are located in difficult-to-reach regions. In this thesis we explore whether a subtle but important fluid flow mechanism, called diffusioosmosis , can produce "chemically-driven flows" in dead-end pores, causing transport and exchange of materials. This phenomenon of "transient diffusioosmosis" utilizes the presence of a spatiotemporal ionic gradient across dead-end pores to generate an in situ electric field which drives convection along the charged walls of the pores. Unlike pressure-driven flow mechanisms where the wall acts as a "resistance", in diffusioosmotic flows the wall acts as a "pump" with the salt gradient acting as a "localized battery" generating motion.

ISBN: 9781321937572Subjects--Topical Terms:

560457
Chemical engineering.

Self-generated diffusiophoresis in dead-end pores.
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100 1 $a Kar, Abhishek. $3 3185916
245 1 0 $a Self-generated diffusiophoresis in dead-end pores.
300 $a 188 p.
500 $a Source: Dissertation Abstracts International, Volume: 76-12(E), Section: B.
500 $a Adviser: Darrell Velegol.
502 $a Thesis (Ph.D.)--The Pennsylvania State University, 2015.
520 $a Dead-end pores are ubiquitous in nature, from extracellular matrix in the brain to fractured porous media present in oil reserves. In many cases one would gain great advantage to be able to design transport in these dead-end pores. However, achieving fluid flows in dead-end pores is not possible through conventional pressure-driven mechanisms. Traditional electrokinetic flows produced by inserting electrodes are also impractical, especially when these pores are located in difficult-to-reach regions. In this thesis we explore whether a subtle but important fluid flow mechanism, called diffusioosmosis , can produce "chemically-driven flows" in dead-end pores, causing transport and exchange of materials. This phenomenon of "transient diffusioosmosis" utilizes the presence of a spatiotemporal ionic gradient across dead-end pores to generate an in situ electric field which drives convection along the charged walls of the pores. Unlike pressure-driven flow mechanisms where the wall acts as a "resistance", in diffusioosmotic flows the wall acts as a "pump" with the salt gradient acting as a "localized battery" generating motion.
520 $a Following a summary of the relevant literature on diffusioosmosis and diffusiophoresis (which refers to particle transport coupled with fluid flow), a brief overview of its applicability in geological settings is provided. Surprisingly, we find strong cues of such flows occurring from sudden tectonic movements on earth's crust as well as during reactive transport phenomena involving dissolution-reprecipitation across rock-fluid interfaces. To illustrate this simple yet important concept, three major scientific questions have been explored: 1) What are the flow rates due to ionic gradients inside dead-end pores, and how far do they extend? Subsequently, how can the transport of mobile species be controlled based on the variation in zeta potentials and other physical parameters? 2) What is the rate at which colloidal fouling can be enhanced or mitigated on membrane surfaces through application of ionic gradients? 3) In pseudomorphic mineral replacement reactions, how do convective flows generated from ionic gradients affect the reaction rate of the system? Consequently, how do these flows enable us to distinguish between reaction and transport limitations along with the quantitative predictions for rate of release of trapped resources from mineral entities?
520 $a Remarkably, colloidal migration generated from such chemical energy are found to be orders of magnitude faster than diffusion time scales and are likely to be critical in various technological operations like hydraulic fracking and waste water purification.
520 $a The two key results discussed in this thesis are: (a) Electrokinetic flows, e.g. diffusioosmosis, generated from mineral dissolution is a novel way of interpreting mass transfer with the external surrounding, and (b) these flows can drive convective particle migration where other forms of fluid flow are difficult to be set up.
520 $a This work constitutes a significant advancement in the field of auto-electrokinetic transport, i.e. diffusiophoresis, and signifies its importance in several physical and geological settings. It proposes an alternate way of driving motion in otherwise inaccessible regions, which can be synergized with synthetic nanomotors and micropumps to induce directionality in micro- and nanoscale transport.
590 $a School code: 0176.
650 4 $a Chemical engineering. $3 560457
650 4 $a Geochemistry. $3 539092
650 4 $a Nanotechnology. $3 526235
690 $a 0542
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710 2 $a The Pennsylvania State University. $b Chemical Engineering. $3 3185917
773 0 $t Dissertation Abstracts International $g 76-12B(E).
790 $a 0176
791 $a Ph.D.
792 $a 2015
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3715523