Date of Award

Spring 5-21-2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Ishrat M. Khan, Ph.D.

Second Advisor

Cass Parker, Ph.D.

Third Advisor

James L. Reed, Ph.D.

Abstract

Nanoscale particles based on the nature of building blocks often self-assemble into superstructures with distinctive spatial arrangements which can be used as functional materials for different application. Micro-phase separated hairy nanoparticle with helical hair can self-assemble to form supramolecular material which may mimic the properties and functions of the natural polymers such as protein and cellulose. Beside this hairy/core-shell nanoparticles also may find many applications such as in asymmetric catalysis, nano-fillers in tire and rubbers, model systems for biology, lithography and as sensors. In this work, we have successfully synthesized two hairy nanoparticles both of which has cross-linked polystyrene core with helical poly (3- methyl 4- vinyl pyridine) and poly (2- methoxystyrene) brushes respectively by living anionic polymerization via one-pot synthesis. NMR spectroscopy was used to determine that polymerization was successful and compositions of HNPs have the agreement with the targeted HNPs structure. By tailoring the architecture (functionalization of polymer chains, the degree of polymerization, grafting density) of HNPs, it is possible to control the final properties of the system. Differential Scanning Calorimetry was used to demonstrate the thermal properties of the synthesized HNPs which corresponds to polymer composition. Dynamic light scattering, SEM and AFM images were recorded to measure the particle size and morphology of the particles. Circular dichroism spectroscopy was used to determine the induced chirality of helical polymer brushes by complexing it with the small chiral molecule. SEM and AFM imaging were recorded to find out the morphology and hierarchically self-assembly of the hairy nanoparticle system. The synthesized particles may have great potential to successfully generate self-assembled suprastructures which can further solve the chiral resolution problem and can also find different applications.

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