Quantum dot - polymer nanocomposites: New materials for dispersion, encapsulation, and electronic applications

• Main Author: Sill, Kevin N
• Language: ENG
• Published: ScholarWorks@UMass Amherst 2006
• Subjects: Polymers|Materials science
• Online Access: https://scholarworks.umass.edu/dissertations/AAI3242311

Tremendous advances in the synthesis and functionalization of nanoparticles over the past twenty years have resulted in remarkable discoveries in the field of nanotechnology. One such development is found in quantum dots, semiconductor nanoparticles that exhibit unique optical and electronic properties not found in the bulk. Research efforts associated with the combination of quantum dots and polymers center on uniting the mechanical or processing properties of the polymer with the optical properties of the quantum dot. Simply blending polymers with nanoparticles typically leads to nanoparticle aggregation, which negates the inherent advantageous properties of the quantum dots. The development of organic and polymer ligands for nanoparticle surface modification enables the preparation of dispersed nanocomposites that retain, or even enhance, the original nanoparticle properties. Presented here is the synthesis of functionalized nanoparticles that are tailored for the growth of polymers directly from the particle surface. Initial studies focused on the preparation of nanoparticle-polymer hybrid materials where the nanoparticles were evenly dispersed throughout the polymer. A method was developed to cross-link polymers grafted from the nanoparticle in an encapsulating shell, with the goal of minimizing nanoparticle degradation. In addition, polymerization chemistry from quantum dot surfaces was modified and optimized to produce conjugated polymer-quantum dot composites. The coupling of these two electronically active components gave composite materials with very unique optical properties that hold potential as displays, sensors, and light-emitting materials.