Title

Stabilized Metal Nanoparticle-Polymer Composites: Preparation, Characterization and Potential Applications

Date of Award

2008

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Photochemical Sciences

First Advisor

Douglas C. Neckers, PhD

Second Advisor

George S. Bullerjahn, PhD (Committee Co-Chair)

Third Advisor

Robert Micheal McKay, PhD (Committee Member)

Fourth Advisor

Deanne L. Snavely, PhD (Committee Member)

Fifth Advisor

Thomas H. Kinstle, PhD (Committee Member)

Abstract

Metal nanoparticle-polymer composites have created a new generation of materials that exhibit unique electrical, optical, or mechanical properties making them attractive for applications in areas like optics, photoimaging and patterning, sensor design, catalysis, and as antimicrobial coatings. The present thesis describes the synthesis, characterization, and incorporation of stabilized metal nanoparticles like those of copper, gold, and silver into a polymer matrix as well as their potential applications.Biofouling has been a worldwide problem for seagoing vessels and other structures exposed to the aquatic environment. Its prevention remains a major challenge and there is a need to develop antifouling systems that exhibit active durability, are easily affordable and eco-friendly. The first part of the thesis demonstrates the antifouling potential of copolymerizable acrylic-functionalized copper (Cu) nanoparticles (NPs). The Cu NPs can be chemically integrated to a polymer backbone, providing a tighter control of the leaching of the metals from the matrix. Biological experiments show that the newly synthesized composites exhibit antimicrobial activity similar to that of conventional copper-based biocides present in most antibacterial and marine antifouling coatings. Therefore, these materials may have value for the development of antibacterial paints and coatings for household materials, hospital and food storage equipment, as well as to reduce biofouling on ships. In addition, a novel photochemical route for incorporation of stabilized metal nanoparticles into a polymer matrix without the use of conventional photoinitiators is illustrated. Charge separated states of 5-mercapto-2,2'-bithiophene (BTSH) functionalized metal NPs generated upon exposure to UV light are active intermediates that can cause polymerization of an acrylic monomer. Electron microscopy data reveal uniform distribution of the NPs within the polymer matrix. These composites may also find useful application as conductive polymeric nanomaterials. Furthermore, the cure performance of light emitting diodes (LEDs) is compared to that of conventional light sources in the UV light cured acrylate formulations. Polymerization rates and properties of the resulting coatings indicate that UV LEDs can be good alternatives to conventional light sources for a variety of applications.