Polymer Chemistry Commons^™

Addressing The Issues Of Drug Delivery Via Advanced Macromolecular Design, Brooks Allen Abel

Dissertations

The work described in this dissertation focuses on the development of synthetic approaches toward novel polymer architectures that specifically address the issues of in vivo drug delivery. Successful implementation of the synthetic methodologies described herein required fundamental investigations into the underlying chemistries in ways that now provide greater insights into the nature of the these chemical reactions.

In Section I, the synthesis of tunable pH- and CO₂-responsive sulfonamide-containing polymers using reversible addition-fragmentation chain transfer (RAFT) polymerization is described. Initially, poor polymerization control of methacryloyl sulfonamide (MSA) monomers was observed using traditional RAFT polymerization conditions. Ultimately, reducing the polymerization …

Using Intrinsic Properties Of Polyaniline To Sense Expression Of The Microrna Let-7, Jared N. Gloria

Honors Theses

MicroRNAs are approximately 22-nucleotide long RNA molecules that function through decay and translational repression of messenger RNA. The microRNA let-7 is found to play a role in maintaining the fate of differentiated cells in humans. Thus, expression level of this microRNA is a reliable biomarker of tumor cell phenotype. However, there are significant limitations in the current profiling techniques of microRNA. The current methods like northern blotting, microarrays, RT-PCR, or using locked nucleic acid (LNA) for in-situ hybridization are either laborious, semi-quantitative, or expensive. In this research we try to address this issue by developing a fast, specific, and inexpensive …

The Effect Of Acrylic Acid On Ring Formation In Polyacrylonitrile, Elisha Cade Willis

Honors Theses

The addition of comonomers into carbon fiber precursor, polyacrylonitrile (PAN), has shown to have effects on the extent of stabilization and thermal behavior.1 Acrylic Acid (AA) was added at varying initial apparent weight percent and added via semibatch reaction to copolymerize with acrylonitrile to form carbon fiber precursor. Accompanying batch reactions were synthesized for comparison. Degradation was found to be greater in the semibatch reactions although overall was comparable to the batch reactions. Differential scanning calorimetry (DSC) confirmed the addition of higher concentrations of AA into the reaction resulted in a less intense exotherm upon cyclization, along with a greater …

Improving And Understanding Inter-Filament Bonding In 3d-Printed Polymers, Madeline S. Stark

Chancellor’s Honors Program Projects

No abstract provided.

Synthesis Of Microgel Polymers As Catalysts, Hannah N. Miller

Chemistry & Biochemistry Undergraduate Honors Theses

New developments in organic synthesis show promise in achieving the best catalytic properties for the hydrolysis of glycosidic bonds through microgel polymers and transition metal complexes. A monomer mix of ethylene glycol dimethacrylate, butyl acrylate, and styrene form miniemulsion polymers after sonication and exposure to UV light. Gravimetrical analysis is used to determine the most suitable polymerization conditions by performing experiments at varying pH values, temperatures, monomer amounts, initiator amounts, and lamp heights. The final data show that the best polymerization conditions are a pH of 10.50 at 0°C with a high monomer ratio, 20% initiator amount, and a lamp …

Synthesis Of Acceptors For Use In Donor-Acceptor Copolymers And Characterization Of These Polymers, William D. Walker

Honors Theses

In this thesis, a selenium-derivatized acceptor was synthesized to examine the heavy atom effects of selenium on the position of the frontier molecular orbitals (HOMO/LUMO band gap) as opposed to sulfur in a donor-acceptor copolymer for use in light harvesting and detection applications. Over the course of this research, standard operating protocols for ultraviolet-visible (UV-Vis-NIR) and Fourier transform infrared (FT-IR) spectroscopies, as well as cyclic voltammetry (CV) characterization techniques were established. Once synthesized, the polymers were characterized through use of the established characterization protocols. The selenium-derivatized polymer exhibited a bathochromic shift compared to the sulfur analogue, with a solid-state absorption …

Functionalizing Β-Cyano Oligo(P-Phenylene Vinylene) Chromophores For Use In Mechanochromic Materials, Alexander J. Wink

Honors Theses

Mechanochromic materials are materials that change color upon mechanical deformation. This concept can be applied in areas of quality control, since the knowledge of damaged parts will easily be detected due to a color change in the material that has undergone deformation. Typically these types of materials are enabled by employing functional small molecules. Often, these are conjugated organic molecules or chromophores, which fluoresce different colors determined by the stimulus (or lack thereof) acting upon the material. In this work, we explore a new avenue to elicit color changes in polymeric materials based on the process of restriction of intramolecular …

Incorporating Carbon Nanotubes Into Carbon Fiber Via Surface Modification, Robert Benjamin Ripy

Masters Theses

Ever more advanced materials need to be designed to further the exploration of avenues of science and engineering. Metals and traditional composites are not meeting the needs of today’s stringent demands for lightweight and strong materials. There is a need for advanced materials that are lighter and stronger to replace conventional materials; carbon fiber composites became the obvious choice because of their outstanding mechanical properties. Polyacrylonitrile (PAN) based carbon fiber has reached its apex in terms of its strength to weight ratio. Carbon nanotubes (CNTs) offer a lightweight and potentially stronger alternative to PAN based fibers. However, it is difficult …

To Bend Or Not To Bend – Are Heteroatom Interactions Within Conjugated Molecules Effective In Dictating Conformation And Planarity?, Gary Conboy, Howard J. Spencer, Enrico Angioni, Alexander L. Kanibolotsky, Neil J. Findlay, Simon J. Coles, Claire Wilson, Mateusz B. Pitak, Chad Risko, Veaceslav Coropceanu, Jean-Luc Brédas, Peter J. Skabara

Chemistry Faculty Publications

We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability.

Novel Non-Halogenated Flame Retardant Compounds, Austin Bailey, Charles J. Neef, Time Dawsey

Poster Presentations

Two different boron compounds, bis(tetramethylammonium) decaborate, TMAD, and bis (tetrabutylammonium) decaborate, TBAD were studied as potential replacements for halogenated flame retardants. Current commercially available, halogenated flame retardants are not environmentally friendly and release strong acids upon burning. TMAD and TBAD were combined with triphenylphosphine oxide and cast in polyurethane films at varying levels. These samples were then cut into strips and burned in a UL-94 flame chamber. These samples were also tested via TGA for degradation temperature. These varying levels were tested via several Design of Experiments constructed within Minitab software. Results thus far have shown the potential for these …

Modified Yttrium Hydroxide/Mc Nylon Nanocomposites And Scaling Effects In Multilayer Polyethylene Films, Jia Chen

USF Tampa Graduate Theses and Dissertations

In this thesis, monomer casting (MC) nylon was synthesized. MC nylon could replace nonferrous metals in certain applications, including gears, wheels, and other moving parts. However, compared with metals, MC nylon products have poor strength and stiffness, and crack easily, especially at low temperatures. In addition, the dimensional stability of MC nylon is poor, especially in the large casting nylon products, causing significant internal stresses due to shrinkage. Thus, MC nylon cracks easily when cast and molded. The yttrium hydroxide particles were modified by stearic acid and dispersed in the caprolactam. The polymerization time was short due to fast anionic …

Design Of Romp-Based Protein Mimics For Sirna Delivery, Brittany M. Deronde

Doctoral Dissertations

Designing delivery agents for therapeutics is an ongoing challenge. As treatments and desired cargoes become more complex, the need for improved delivery vehicles becomes critical. Excellent delivery vehicles must ensure the stability of the cargo, maintain the cargo’s solubility, and promote efficient delivery and release. In order to address these issues, many research groups have looked to nature for design inspiration. Proteins, such as HIV-1 TAT and Antennapedia homeodomain protein, are capable of crossing cellular membranes. However, due to the complexities of their structures, they are synthetically challenging to reproduce in the laboratory setting. Being able to incorporate the key …

Stimuli Responsive Polymer Self-Assembly And Disassembly, Jiaming Zhuang

Doctoral Dissertations

Stimuli responsive polymer assemblies have been long investigated for drug application due to their flexibility for surface functionalization to achieve desired interfacial property and capability of acting as a host for payloads encapsulation. These interfacial and host-guest properties are very critical and need to be customized really depending on nature of cargos and specific delivery application. More importantly, these properties are always desired to be adaptable in different environments. For instance, adjustable interfacial property can facilitate the carrier to overcome a variety of different barriers before it reach the target while changeable host-guest property allows to selectively releasing the payload …

Refractive Index Engineering And Optical Properties Enhancement By Polymer Nanocomposites, Cheng Li

Doctoral Dissertations

The major part of this dissertation discusses the engineering of the refractive index of materials using solution-processable polymer nanocomposites and their applications in building optical components and devices. Three particular polymer nanocomposites have been introduced to achieve materials with tunable refractive indices and enhanced optical properties, which can be used to manipulate the behavior of light or electromagnetic radiations. In the first system, polyhedral oligomeric silsesquioxane (POSS)/polymer nanocomposites are developed. Thin films with tunable, low refractive indicies were fabricated from the composites. The mechanical strength of these films was characterized, and their application in antireflective coatings is discussed. In the …

(I) Polymer Nanocomposites: Rheology And Processing For Mesoporous Materials And (Ii) Nanopatterning Of Metal Oxides Using Soft Lithography, Rohit Kothari

Doctoral Dissertations

The research in this dissertation is categorized into two parts. The first part is focused on investigation of order-to-disorder transitions (ODT) in nanocomposites of an amphiphilic block copolymer containing various hydrogen-bonded additives, and fabrication of novel mesoporous silica based materials by utilizing such nanocomposites as templates. Disordered Pluronic®, poly(ethylene oxide) (PEO)−poly(propylene oxide) (PPO)−PEO triblock copolymer upon blending with small molecule additives containing hydrogen-bond-donating functional groups (carboxyl or hydroxyl) result into ordered nanoscale morphologies by preferentially interacting with the hydrophilic PEO chains in the Pluronic®. The dependence of ODT-temperature in these novel Pluronic®/small-molecule-additive complexes on composition, number and type of functional …

Conjugated Polymer-Based Biomaterials Through Controlled Self-Assembly, Megan Twomey

FIU Electronic Theses and Dissertations

Synthetic polymeric materials have gained significant use as biological materials (biomaterials) in biomedical and pharmaceutical applications. As a result, a demand for well-defined polymers with tunable properties has emerged. The synthetic versatility of polymeric biomaterials allows the opportunity to understand the structure-property relationship of materials and their cellular interactions. A novel class of polymeric biomaterials are conjugated polymers (CPs), which possess desirable physicochemical and excellent photophysical properties, including inherent fluorescence. The synthetic versatility of CPs allows easy modification of the conjugated backbone to tune emission and side chain structures to adjust biocompatibility through increased water solubility, controlled biodegradability, and incorporation …

Toward High Performance Nanocarbon Fibers, Michaela R. Pfau

Master's Theses

High performance carbon fibers (CFs) have been a commercially available since their commercial boom in the 1970s, and are generally produced via carbonization of poly (acrylonitrile) (PAN). More recently, carbon nanomaterials like graphene and carbon nanotubes (CNTs) have been discovered and have shown excellent mechanical, thermal, and electrical properties due to their sp² carbon repeating structure. Graphene and CNTs can both be organized into macroscopic fibers using a number of different techniques, resulting in fibers with promising mechanical performance that can be readily multifunctionalized. In some cases, the two materials have been combined, and the resulting hybrid fibers have …

Synthesis And Characterization Of Segmented Fluorescent Conjugated Polymers Via Acyclic Diene Metathesis (Admet), Gagandeep Singh

Dissertations, Theses, and Capstone Projects

This doctoral thesis is focused on the novel and facile synthesis and characterization of segmented conjugated polymers featuring various electro-optically active segments, with or without heteroatom linkages. The polymers were synthesized, via acyclic diene metathesis (ADMET) using ruthenium-based Grubbs-type catalysts. All products are soluble, and have a well-defined all-trans microstructure without defects. Some of the polymers were also synthesized via Suzuki polycondensation for comparison purposes. All monomers utilized were designed and synthesized in the laboratory.

Segmented conjugated polymers have received a great deal of attention in organic electronics, such as organic light emitting-diodes, organic field-effect transistors and organic solar …

Water Condensation And Protein Adsorption On Hybrid Superhydrophobic-Hydrophilic Surfaces, Bikash Mondal

Dissertations, Theses, and Capstone Projects

This thesis describes the study of protein adsorption and water condensation on hybrid superhydrophobic-hydrophilic surfaces for various technological applications such as diagnostics, artificial organs and medical devices, water collection, and heat transfer.

In the chapter 1, a general introduction to wetting theories, superhydrophobic surface, and hybrid surfaces is given. In chapter 2, design and fabrication of a hybrid superhydrophobic surface for studying dropwise condensation and heat transfer is discussed. Effect of surface chemistry and wettability on protein adsorption is discussed in the chapter 3. Finally, in chapter 4, the protein adsorption study on hybrid superhydrophobic surfaces made by 3D-printing and …

Purification Of Synthetic Oligonucleotides, Shiyue Fang

Michigan Tech Patents

This invention provides a method for purifying synthetic oligonucleotides comprising capping, polymerizing and separating any failure sequences produced during oligonucleotide synthesis. The invention also provides a method for purifying synthetic oligonucleotides comprising reacting a full length oligonucleotide with a compound to attach a polymerizable functional group to an end of the full length oligonucleotide, polymerizing the full length oligonucleotides and removing the failure sequences, and recovering the full length oligonucleotides. The invention also provides novel capping agents having a polymerizable functional group, and kits comprising at least one composition of the present invention.