Date of Award

Spring 2019

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

First Advisor

Morgan Stefik

Abstract

Nanomaterials are often fabricated using block polymers to direct the placement of nanoparticles via selective intermolecular interactions such as hydrogen bonding. Fluorophobic interactions have emerged as a promising handle to control nanoparticle placement independently from typical hydrophilic approaches. A series of nanoparticles with tunable fluorophobicity were prepared to elucidate the key parameters for harnessing fluorophobic interactions in this context. Mixed ligand fluorinated nanoparticles (ML-FNPs) where prepared to examine the competing roles of each ligand towards fluorophobicity and solubility. The ML-FNP intermolecular interactions were first studied using a custom-made Quartz Crystalline Microbalance (QCM) based technique. The ML-FNPs were then examined for compatibility with polymer processing using homopolymers and block copolymers. Strong repulsion of all ML-FNPs was observed in all lipophilic polymer domains while increasing the fluorine content continually enhanced dispersion in the perfluorinated domains. With as little as 25% fluorine in the ligand shell ML-FNPs were assembled in the PFOA domain near the interface, as the fluorine content exceeded 75% the ML-FNPs assembled at the interface and within the center of small PFOA domains. Finally, preliminary experiments combining ML-NPs with hydrophilic NPs led to the first ordered composite film with distinct control over two different NP types.

Rights

© 2019, Zachary Michael Marsh

Included in

Chemistry Commons

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