Theses Doctoral

Self-organization in systems of anisotropic particles

Miller, William Leneal

This dissertation presents studies on self-organization in soft matter systems. A wide variety of systems is studied, with the goal of understanding both the nonequilibrium and the equilibrium properties of this important process. In Chapter 2, we study the self-assembly of asymmetric Janus colloidal particles. We identify and systematically describe the effect of the ratio of hydrophobic to hydrophilic surface area on the nonequilibrium processes and structure formation. In Chapter 3, we examine systems of hard, aspherical particles. We demonstrate that the thermodynamics of self-organization of a system of these aspherical particle (either a system of identical particles or a polydisperse system of different-shaped particles) is well-predicted by a simple relationship between the crystallization pressure and two measures of particle asphericity borrowed from other fields. In Chapter 4, we shift focus to systems of soft particles in two dimensions and on the surface of a sphere. Soft particles are particles with a nite interaction potential at zero distance; such particles exhibit a surprisingly large variety of ordered structures at equilibrium. A similar phenomenon is seen when the study is extended to soft particles on the surface of a sphere.In Chapter 5, we study the free energy of two-component polymer brush systems in which polymers of different length are patterned in alternating stripes of specified widths on the surface of a cylinder. We present the dependence of the free energy on the polymer lengths and stripe width and a qualitative explanation of its functional form. Finally, in Chapter 6, we approach the reverse self-assembly problem. That is, we describe an algorithm for answering the reverse (and much more dicult) question, "Given a specic desired target self-assembled structure, what interparticle interactions will yield a system which will self-assemble into that structure?" We also describe a new model of interparticle interaction which should be able to generate interparticle interaction geometries with a high degree of flexibility.


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More About This Work

Academic Units
Chemical Physics
Thesis Advisors
Cacciuto, Angelo
Ph.D., Columbia University
Published Here
June 7, 2012