Date of Award

Spring 2016

Project Type

Dissertation

Program or Major

Materials Science

Degree Name

Doctor of Philosophy

First Advisor

Erik B Berda

Second Advisor

John Tsavalas

Third Advisor

Glen P Miller

Abstract

The methodology towards the creation of nanoscale polymeric objects by way of the folding of single polymer chains has been enjoying success in the field of polymer chemistry and materials science. By synthesizing polymer chains with built in functionality either through functional side groups, or direct incorporation into the polymer backbone, polymer chemists are able to fold single polymer chains onto themselves through a broad range of covalent and non-covalent interactions in dilute solution. These compact, nano-sized objects can now be used in a wide arrange of functions and applications.

The aim of this dissertation is to provide first, a comprehensive overview of the recent advances and success enjoyed by this field and second, to showcase some of the various routes towards the dynamic and modular creation of these single-chain polymer nanoparticles (SCNPs).

Chapter 2 of this work discusses the use of dynamic covalent cross-linking chemistry via reversible disulfide bridges in the folding and unfolding of SCNPs. Through the use of triple detection size-exclusion chromatography (SEC) it was shown through changes in retention time, a phenomena indicative of hydrodynamic volume, a polymer was being folded into compact SCNPs and then unfolded and refolded via redox chemistry. Chapter 3 explores the design of polymers that had various different cross-linkable moieties incorporated into the monomer side units. By having cross-linkable moieties that can undergo different chemical cross-linking reactions (i.e thiol-yne click reactions, epoxide ring-opening reactions, activated esters), a modular approach towards the folding and subsequent functionalization of SCNPs is created. Looking to design a system with a greater degree of control over the modular functionality, chapter 4 investigates the use of norbornene imide monomers containing pentafluorophenyl activated esters with varying methylene spacer unites between the polymerizable olefin and the activated ester. It was here that an unexpected phenomena was observed; the doping effects of fluorinated aromatic hydrocarbons (FAHs) on second and third generation Grubbs’ catalysts. This chapter aims to shed some light on this subject. Finally in chapter 5 an additional click-chemistry reaction is observed to take place with pentafluorophenyl methacrylate. Thiol-para fluoro click reactions are used to react with the pentafluorophenyl activated esters, while still leaving the ester moiety reactive towards primary alkyl amines.

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