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Polymer networks with mobile force-applying crosslinks

Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: We construct and study a simple model for an active gel of
exible polymer filaments
crosslinked by a molecular motor cluster that perform reversible work while translating
along the filaments. The filament end points are crosslinked to an elastic background.
In this sense we employ a simplified model for motor clusters that act as slipping links
that exert force while moving along the strands. Using the framework of replica theory,
quenched averages are taken over the disorder which originates from permanent random
crosslinking of network end points to the background. We investigate how a small motor
force contributes to the elastic properties of the network. We learn that in addition to
the normal elastic response for the network there is an extra contribution to the network
elasticity from the motor activity. This depends on the ratio of the entropic spring constant
for the linked bio-polymerchain to the spring constant of the tether of the motor. / AFRIKAANSE OPSOMMING: Ons konstrueer en bestudeer 'n eenvoudige model vir 'n aktiewe netwerk van
eksieble
polimeerfilamente wat deur grosse van molekulere motors aan mekaar verbind word wat
omkeerbare werk doen terwyl dit langs die filamente transleer. Die eindpunte van die filamente
is aan 'n elastiese agtergrond verbind. In hierdie sin benut ons 'n eenvoudige model
vir motorclusters wat as verskuifbare verbindings krag op die filamente tydens beweging
kan uitoefen. Nie-termiese wanorde gemiddeldes word geneem oor die wanorde wat deur
die lukrake permanente verbindings van netwerk eindpunte aan die agtergrond veroorsaak
word. Ons ondersoek hoe 'n klein motorkrag tot die elastiese eienskappe van die netwerk
bydra. Ons leer dat daar bo en behalwe die gewone elastiese respons vir die netwerk 'n
elastiese bydrae as gevolg van die motors se aktiwiteit voorkom. Dit hang af van die verhouding
van die entropiese veerkonstante van die biopolimerketting tot die veerkonstante
van die anker van die motor.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/6759
Date03 1900
CreatorsMateyisi, Mohau Jacob
ContributorsMuller-Nedebock, Kristian, Boonzaaier, Leandro, University of Stellenbosch. Faculty of Science. Dept. of Physics.
PublisherStellenbosch : University of Stellenbosch
Source SetsSouth African National ETD Portal
Languageen_ZA
Detected LanguageUnknown
TypeThesis
Format68 p. : ill.
RightsUniversity of Stellenbosch

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