Title

Growth of Polymer Films By Driven Deposition: Monte Carlo Simulations

Date of Award

2004

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics and Astronomy

First Advisor

Ras Pandey

Advisor Department

Physics and Astronomy

Abstract

Growth of polymer films continues to be of great interest to researchers both for the understanding of the underlying physics as well as the applications in developing new materials. Computer simulations have proven to be useful tools in the study of polymer systems, and stochastic (Monte Carlo) simulations are used here to investigate growing polymer films by deposition. The polymer chains move on a cubic lattice where each monomer unit can move according to a set of rules and are driven towards the substrate by an external field. We begin with the relatively slow (single-monomer) kink-jump dynamics, however, incorporation of faster modes such as crankshaft and reptation movements seems crucial in relaxing the interface width. The structure of the chains are analyzed by evaluating the conformation at the wall, in the bulk, at the interface, and in solution. The polymer density profile is also examined at the substrate, throughout the bulk, and at the interface. Growth and roughness of the interface for deposited polymer chains are studied by evaluating the interface width, its development over time, steady-state, and equilibrium values. The growth characteristics for the interface are compared to those using particle deposition models. Also, the dependence of the interface width on chain length, field strength, and temperature is investigated by varying these parameters in order to establish empirical laws and scaling relationships.