Faculty Advisor

John C. MacDonald

Faculty Advisor

W. Grant McGimpsey

Faculty Advisor

James P. Dittami

Faculty Advisor

Nicholas Kildahl

Faculty Advisor

Danial D.M. Wayner

Abstract

The rational design, synthesis, and characterization of several systems that undergo self-assembly are described. Systems were chosen based on their ability to self-assemble in a highly ordered and predictable fashion that imparts order on the structure such that it is able to perform a given device function. Herein we describe self-assembled multilayered thin films on gold that can behave as molecular wires with tunable length, photocurrent generating films, and surfaces with photoswitchable wettability, and self-assembling peptide nanotubes that can potentially function as long range energy and electron transfer conduits. A non-covalent, modular approach to multilayered thin film fabrication was used to generate three thin film systems that function as molecular scale wires, photocurrent generating devices, and photoswitchable thin films, respectively. These films were based on 4-[(10-mercaptodecyl)oxy]pyridine-2,6-dicarboxylic acid self-assembled monolayers on gold. These monolayers are able to chelate metal (II) ions, and thus multilayers were assembled based on metal-ligand coordination chemistry. The three systems described were characterized by contact angle measurements, electrochemical methods, and grazing angle IR spectroscopy. All three systems emphasize the versatility of a modular approach to thin film construction, and provide proof-of-concept for future studies. A cyclic octapeptide architecture was employed as a scaffold for the predictable self-assembly of photoactive groups within a nanotubular structure. The degree of cyclic peptide aggregation in stacking nanotube systems and non-stacking monomer systems, was studied via fluorescence emission spectroscopy. Based on the spectral results, it was determined that peptide nanotubes can be constructed such that photoactive side chains can be assembled in stacks. Future experiments for the determination of long range energy and/or charge transfer in these systems are also discussed.

Publisher

Worcester Polytechnic Institute

Degree Name

PhD

Department

Chemistry & Biochemistry

Project Type

Dissertation

Date Accepted

2004-04-30

Accessibility

Unrestricted

Subjects

nanotechnology, thin films, nanotubes, Molecular Self Assembly, Thin films, Nanotechnology, Monomolecular films, Self-assembly (Chemistry)

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