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Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Polymer Science and Engineering

Year Degree Awarded

2015

Month Degree Awarded

September

First Advisor

Gregory M. Grason

Second Advisor

Christian D. Santangelo

Third Advisor

Ryan C. Hayward

Fourth Advisor

Murugappan Muthukumar

Subject Categories

Statistical, Nonlinear, and Soft Matter Physics

Abstract

In this dissertation I present a study of the geometry and energetics of bundles composed of flexible cohesive filaments. This is a general class of materials, both biological and artificial, existing across many length scales. The aim of this thesis is to investigate the interdependence between the 2D organization of filaments in a bundle’s cross section, and the 3D structure, with an emphasis on the twisting mode of deformation. First we present a model of filament contacts and interactions, which we employ in numerical simulations to study the connection between the ground state energies of constant-pitch bundles and their interior packing topology. We then focus on exterior features, and construct a continuum model of the surface energy and its twist-dependence. Finally, we employ a fully 3D model of filament bundles with a fixed packing topology to examine the connection between filament organization and the resulting 3D structures, be they twisting, writhing, bending, undulating, or other modes of deformation.

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