Polymer Chemistry Commons^™

Polymers For Dna Binding, Sue Yuan Li

Dissertations

No abstract provided.

Synthesis, Characterization, And Functionalization Of 2-Vinyl-4,4-Dimethylazlactone Brushes To Create Bio-Inspired Materials, Camille Marie Kite

Masters Theses

Functional materials built from polymer scaffolds inspire many potential uses, including as biomaterial surfaces or sensors. In situ functionalization using well-defined polymer “brushes” made by tethering polymer chains to a surface by one of their ends is explored. Specifically, poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) chains, which contain a reactive azlactone ring at each repeat unit, are tethered to a surface to create brushes and these films are functionalized using a variety of small molecules, primarily amines or peptides. Relationships between polymer brush thickness, size of the functionalizing molecule, solution concentration, reaction time, and extent of functionalization were determined through measurements of ...

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

Chemistry Publications and Other Works

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) of hairy particles from water to [EMIM][TFSA] upon heating was a linear function of the cloud point (CP) of corresponding free polymer in [EMIM][TFSA]-saturated water. Chapter 2 presents the synthesis and study of thermo- and pH-sensitive hairy particles. A small amount ...

In Situ Measurements Of Electron-Beam-Induced Surface Voltage Of Highly Resistive Materials, Joshua Hodges

All Graduate Theses and Dissertations

This study presents the development, calibration, characterization, and use of new instrumentation for in situ measurements of electron-beam-induced surface voltage. The instrument capabilities allow for measurements of a full range of insulating materials that are of concern to NASA spacecraft charging experts. These measurements are made using moveable capacitive sensor electrodes that can be swept across the sample using an in vacu stepper motor. Testing has shown a voltage range of more than ±30 kV with a low-voltage resolution of 0.2 V. The movable sensors allow for a radial measurement of surface voltage with spatial resolution as low as ...

The Role Of Non-Bonding Interactions And Bonding Schemes In The Structure And Properties Of Multi-Component Polymer Systems, Caleb Will Dyer

Doctoral Dissertations

This dissertation addresses three aspects of multi-component polymer systems. Chapter 2 details work on understanding the effect of precise polymeric structure on the phase behavior of blends containing cellulose acetate chains with different levels of acetate substitution. The difference in degree substitution (Delta DS) between the two components in the blend is systematically changed from .06 to .63, where each blend is found to be partially miscible. The samples containing higher acetate content demonstrate decreased miscibility as Delta DS increases. The sample with the most hydroxyl groups, however, has greater miscibility than samples of similar Delta DS, but fewer hydroxyl ...

Understanding The Thermodynamic Behavior Of Nanoparticles To Tailor Polymer Nancomposite Structure, Mary Catherine Mutz

Doctoral Dissertations

The work presented in this dissertation is an attempt to understand the entropic and enthalpic forces that govern the dispersion and dissolution of nanoparticles in solutions and in thin polymer films with the end-goal of producing highly tailored products.

In the first part, neutron reflectivity was used to study the impact of nanoparticle presence on the surface segregation of deuterated polystyrene (dPS) in a polystyrene matrix. The impact of the presence of cylinders (carbon nanotubes), sheets (graphene), and spheres (polystyrene soft nanoparticles) on the surface segregation process and ultimate structure were examined. Experimental data indicate that the presence of the ...

Nonlinear Propagation Of Incoherent White Light In A Photopolymerisable Medium: From Single Self-Trapped Beams To 2-D And 3-D Lattices, Kailash Kasala

Open Access Dissertations and Theses

Optical beams that travel through a material without undergoing divergence are known as self-trapped beams. Self-trapping occurs when a beam induces a suitable index gradient in the medium that is capable of guiding the original beam. An incoherent light consists of femtosecond scale speckles, due to random phase fluctuations and were not thought to self-trap until recently. In 1997, Mitchell et al., showed that white light can self-trap, provided the medium cannot respond fast enough to form index gradients to these speckles individually. However, detailed studies have been hampered by a lack of suitable materials and strategies for enabling such ...

Tuning The Hardness And Wettability Of Methacrylate Polymers, Nicholas Luong

Open Access Dissertations and Theses

Silicones exhibit a fundamentally hydrophobic character. While the incorporation of hydrophilic surface moieties can be achieved by a variety of means, normally surface reversion leads to rapid recovery of hydrophobic surfaces. We were interested to learn if the hydrophobic character of silicones could be manifested on organic polymers and, moreover, if different degrees of wetting of organic surfaces could controlled by simultaneous use of more than one hydrophilic entity.

Herein, we present a method to control the hardness and wettability of methacrylate polymers with the addition of ACR A008-UP, a polymerizable, acrylate-based trisiloxane surfactant. Surface wettabilities were determined through the ...

Application Of Thermally Enhanced Huisgen Cycloaddition On Polysiloxane Functionalization, Mark Pascoal

Open Access Dissertations and Theses

The thermal azide-alkyne cycloaddition using electron deficient alkynes was used to functionalize polysiloxanes at low temperatures and without the need of a metal catalyst. We observed that the temperature at which cycloaddition began can be attributed to the identity of the alkyne's substituents (Chapter 2). We propose that the location of functionalization can be controlled by the specific introduction of electron deficient alkynes on terminal or pendant points on the polysiloxane. Polysiloxanes, each containing two electronically different alkynes, were prepared to show preferential functionalization of the more reactive alkyne without consuming the less reactive alkyne. The alkyne's reactivity ...

The Synthesis Of Dendrimer-Based Radioimaging Agents, Spencer D. Knight

Open Access Dissertations and Theses

The synthesis of new macromolecular diagnostic imaging agents has been a growing field in polymeric chemistry research. Dendrimers provide a viable scaffold for such applications due to their unique, defined macromolecular architecture. The precise structural control afforded via the step-wise synthesis of dendrimers yields exceptional and precise macromolecules that can be functionalized to include necessary imaging moieties with the same degree of precision.

We have herein contributed to this growing field by attempting the synthesis of a series of PEGylated poly(2,2-bis[hydroxymethyl]propanoic acid) PMPA dendrons using thiol-ene "click" chemistry. The series consisted of three dendritic architectures peripherally ...

A Review On The Visible Light Active Titanium Dioxide Photocatalysts For Environmental Applications, Suresh Pillai, Micahel Seery, Nicholas Nolan, Miguel Pelaez, Athanassios G. Kontosd, Polycarpos Falaras, Patrick S.M. Dunlop, Jeremy W.J. Hamiltone, J.Anthony Byrnee, Kevin O’Shea, Mohammad H. Entezari, Dionysios D. Dionysioua

Articles

Development of visible light active (VLA) titania photocatalysts

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO 2) semiconductor mate-rials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applica-tions. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 struc-ture, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization ...

Development Of Reactive Polyanions For Encapsulation Of Live Yest Cells Within Polymer Hydrogel Films, Padraic J. Foley

Open Access Dissertations and Theses

Conformal coating is a promising method of encapsulating therapeutic cells for immunoprotection during implantation in the human body. Therapeutic cells can include donor-derived primary cells, genetically modified lab lines, or stem-cell derived cells, that can express an enzyme or hormone needed by the recipient. Layer-by-Layer (LbL) assembly, a common method for conformal coating, uses sequential deposition of alternating layers of positively and negatively charged polymers. This permits the preparation of small capsules with thin walls that maximize metabolic exchange while protecting cells from the hosts’ immune system. The current work describes the use of auto crosslinking synthetic polyelectrolytes to coat ...

The Development Of Transparent, Processable, Thermally-Responsive Coatings, Christopher David Roland

Master's Theses and Project Reports

Polymer matrices are commonly used as guest-host systems for organic chromophores for use in non-linear optical materials. The chromophores must be aligned or poled in an electric field in order to impart anisotropy and non-linear activity to the material. This poling process raises several issues, the two largest being the eventual relaxation of the chromophores back into random orientations due to brownian motion, and high molecular weight polymer matrices limiting chromophore mobility during poling. The prevention of this relaxation process is an area of significant interest, especially in applications that require long term coating stability and activity. In this study ...

Solid State Chemical Reactions And Polymerizations: The Initial Synthesis Of Dna?, Otto Vogl, Frank T. Traceski

Otto Vogl

A Proposal for Covering individual Macromolecules with Macromolecules including a Realistic Chiral Synthesis of Nucleic Acids.

Justification Of A Nonlinear Schrödinger Model For Polymers, Dmitry Ponomarev

Open Access Dissertations and Theses

A model with nonlinear Schrödinger (NLS) equation used for describing pulse propagations in photopolymers is considered. We focus on a case in which change of refractive index is proportional to the square of amplitude of the electric field and consider 2-dimensional spatial domain. After formal derivation of the NLS approximation from the wave-Maxwell equation, we establish well-posedness and perform rigorous justification analysis to show smallness of error terms for appropriately small time intervals. We conclude by numerical simulation to illustrate the results in one-dimensional case.