Simulation study of a colloidal system under the influence of an external electric field
Thesis (M.Sc.)--Memorial University of Newfoundland, 2010. Physics and Physical Oceanography Includes bibliographical references (leaves 105-107) We perform Monte Carlo simulations to study an electrorheological fluid that consists of spherical dielectric particles in a solution of low dielectric co...
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ftmemorialunivdc:oai:collections.mun.ca:theses4/160800 2023-05-15T17:23:34+02:00 Simulation study of a colloidal system under the influence of an external electric field Almudalla, Ahmad Mustafa, 1982- Memorial University of Newfoundland. Dept. of Physics and Physical Oceanography 2010 xvii, 112 leaves : col. ill. Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses4/id/160800 Eng eng Electronic Theses and Dissertations (12.93 MB) -- http://collections.mun.ca/PDFs/theses/Almudalla_AhmadMustafa.pdf a3295707 http://collections.mun.ca/cdm/ref/collection/theses4/id/160800 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Colloids Dipole moments Electrorheological fluids Monte Carlo method Text Electronic thesis or dissertation 2010 ftmemorialunivdc 2015-08-06T19:22:43Z Thesis (M.Sc.)--Memorial University of Newfoundland, 2010. Physics and Physical Oceanography Includes bibliographical references (leaves 105-107) We perform Monte Carlo simulations to study an electrorheological fluid that consists of spherical dielectric particles in a solution of low dielectric constant under the influence of an external electric field. The electric field induces dipole moments in the colloids that align along to the electric field direction. At a sufficiently high electric field, the dipoles attract each other to form long chains along the electric field direction. The system can then be modeled as a 2D system of interacting disks, where each disk represents a chain of hard sphere dipolar particles viewed along the field axis. The disk-disk interaction varies with chain length, but has the general feature of strong short range attraction and weak long range repulsion. We perform simulations of the 2D fluid across a wide range of temperature and area fraction to study its structural properties and phase behaviour. Our model reproduces the clustered structures seen experimentally. -- In addition, a novel void phase has been seen by two experimental groups in a low volume fraction regime (< 1%). The simulations of our model indicate that dipolar hard spheres, even with the addition of Yukawa and van der Waals interactions, do not produce the void phase. Further investigations employing toy potentials reveal qualitative features of the potential that can give rise to voids, but physical mechanisms that may produce these features remain speculative. Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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English |
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Colloids Dipole moments Electrorheological fluids Monte Carlo method |
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Colloids Dipole moments Electrorheological fluids Monte Carlo method Almudalla, Ahmad Mustafa, 1982- Simulation study of a colloidal system under the influence of an external electric field |
topic_facet |
Colloids Dipole moments Electrorheological fluids Monte Carlo method |
description |
Thesis (M.Sc.)--Memorial University of Newfoundland, 2010. Physics and Physical Oceanography Includes bibliographical references (leaves 105-107) We perform Monte Carlo simulations to study an electrorheological fluid that consists of spherical dielectric particles in a solution of low dielectric constant under the influence of an external electric field. The electric field induces dipole moments in the colloids that align along to the electric field direction. At a sufficiently high electric field, the dipoles attract each other to form long chains along the electric field direction. The system can then be modeled as a 2D system of interacting disks, where each disk represents a chain of hard sphere dipolar particles viewed along the field axis. The disk-disk interaction varies with chain length, but has the general feature of strong short range attraction and weak long range repulsion. We perform simulations of the 2D fluid across a wide range of temperature and area fraction to study its structural properties and phase behaviour. Our model reproduces the clustered structures seen experimentally. -- In addition, a novel void phase has been seen by two experimental groups in a low volume fraction regime (< 1%). The simulations of our model indicate that dipolar hard spheres, even with the addition of Yukawa and van der Waals interactions, do not produce the void phase. Further investigations employing toy potentials reveal qualitative features of the potential that can give rise to voids, but physical mechanisms that may produce these features remain speculative. |
author2 |
Memorial University of Newfoundland. Dept. of Physics and Physical Oceanography |
format |
Thesis |
author |
Almudalla, Ahmad Mustafa, 1982- |
author_facet |
Almudalla, Ahmad Mustafa, 1982- |
author_sort |
Almudalla, Ahmad Mustafa, 1982- |
title |
Simulation study of a colloidal system under the influence of an external electric field |
title_short |
Simulation study of a colloidal system under the influence of an external electric field |
title_full |
Simulation study of a colloidal system under the influence of an external electric field |
title_fullStr |
Simulation study of a colloidal system under the influence of an external electric field |
title_full_unstemmed |
Simulation study of a colloidal system under the influence of an external electric field |
title_sort |
simulation study of a colloidal system under the influence of an external electric field |
publishDate |
2010 |
url |
http://collections.mun.ca/cdm/ref/collection/theses4/id/160800 |
genre |
Newfoundland studies University of Newfoundland |
genre_facet |
Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (12.93 MB) -- http://collections.mun.ca/PDFs/theses/Almudalla_AhmadMustafa.pdf a3295707 http://collections.mun.ca/cdm/ref/collection/theses4/id/160800 |
op_rights |
The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. |
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