Degree Type

Dissertation

Date of Award

2006

Degree Name

Doctor of Philosophy

Department

Materials Science and Engineering

First Advisor

Vladimir V. Tsukruk

Abstract

This study explores possibilities of obtaining of unique self-assembled, nanofibrillar structures from amphiphilic hyperbranched molecules on solid surfaces. To achieve this, we explore the multifunctional properties of hyperbranched polymers which are determined by the nature of the end groups and structure of the chemical composition of the core unit. We established that the combination of hydrophobic interactions and multiple hydrogen bonding events added to the dendritic core structure is responsible for stable assembling into nanofibrillar morphology at the air-water interface at both the nano and at microscales and determined compositional boundaries of this phenomenon;The core-shell architecture of the amphiphilic dendritic molecules suggested here provides exceptional stability of one-dimensional nanofibrillar structures. The critical condition for the formation of the nanofibrillar structures is the presence of both alkyl tails in the outer shell as the hydrophobic component and either amine or carboxyl groups in the shell as the hydrophilic component. The multiple intermolecular hydrogen bonding and polar interactions between flexible cores stabilize these nanofibers and make them robust against surface pressure and solvents. Moreover, discovered assembled nano-fibers formed by hyperbranched polymers have been used for templating of silver nanoparticles via growth from water subphase. We observed that hyperbranched polymers scaffolds can create aligned nanoparticle arrays, and also effectively control size of the particles to about 3 nm.

DOI

https://doi.org/10.31274/rtd-180813-16485

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Maryna Ornatska

Language

en

Proquest ID

AAI3244374

File Format

application/pdf

File Size

174 pages

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