Physical Sciences and Mathematics Commons^™

Synthesis And Temperature-Induced Phase Transfer Behavior Of Thermosensitive Hairy Particles Between Aqueous Solution And A Hydrophobic Ionic Liquid, Jonathan Michael Horton

Doctoral Dissertations

This dissertation presents the synthesis of a family of thermosensitive polymer brush-grafted silica particles and the study of their thermally induced phase transfer behavior between water and a hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMIM][TFSA]). The hairy particles were prepared by surface-initiated atom transfer radical polymerization.

Chapter 1 describes the synthesis and phase transfer behavior of a series of 205 nm silica particles grafted with thermosensitive polymers of methoxyoligo(ethylene glycol) methacrylates. The hairy particles with sufficiently high lower critical solution temperatures underwent reversible and quantitative transfer between water and [EMIM][TFSA] in response to temperature changes. The transfer temperature (T_{tr …}

Probing And Controlling Fluid Rheology At Microscale With Magnetic Nanorods, Alexander Tokarev

All Dissertations

This Dissertation is focused on the development of new methods for characterization and control of fluid rheology using magnetic nanorods. This Dissertation consists of five chapters. In the first chapter, we review current microrheologial methods and develop a Magnetic Rotational Spectroscopy (MRS) model describing nanorod response to a rotating magnetic field. Using numerical modeling, we analyze the effects of materials parameters of nanorods and fluids on the MRS characteristic features. The model is designed for a specific experimental protocol. We introduce and examine physical parameters which can be measured experimentally. The model allows identification of MRS features enabling the calculation …

Production And Characterization Of Electrospan Polymer Nano-Fibers, Anna Sise

Honors Theses

Electrospinning is a process of generating polymer fibers by accelerating a polymer solution through an electric field. The polymer solution is released at a designated rate through a syringe; once the droplet enters the high voltage region, it whips throughout the chamber, landing upon a grounded collector. This procedure results in fibers with a range of diameter from several nanometers to a few micrometers. These fibers can be used in a variety of applications, including drug delivery, filter media, material substrates, optical media, tissue scaffolds, and wound dressing. For my senior thesis, I established the most successful method of creating …

Multipolymer Interactions In Bulk Heterojunction Photovoltaic Devices, Grant Olson

Physics

Multipolymer photovoltaics, single layer devices made up of multiple photoactive polymers, can create organic photovoltaics (OPVs) with a wider spectral response than single polymer systems without the difficult fabrication of a tandem. Our group has successfully created multipolymer solar devices with 2% power conversion efficiency. We have analyzed the optical and electrical properties of these devices, and found that it may be possible for polymers to assist each other with charge extraction, though combining polymers disrupts single polymer crystallinity.

Synthesis Of Self-Immolative Monomers And Their Applications In Polymeric Materials, Matthew A. Dewit

Electronic Thesis and Dissertation Repository

Self-immolative spacers are a unique class of molecules employed in a variety of applications, particularly in the biomedical field. Most commonly, they are molecules containing two reactive termini with a capping group at one terminus and a substrate of interest at the other. Upon removal of the capping group, the spacer undergoes an intramolecular reaction that results in its removal from the molecule and liberation of the substrate. These spacers have been extensively studied in monomeric form within prodrugs, as well as to form dendrimers that have been used for applications such as signal amplification, molecular logic gates and amplified …