Digital Commons Network^™

Non-Destructive Determination Of Surface Area In Reverse Phase Chromatographic Columns, Margaret Figus

Seton Hall University Dissertations and Theses (ETDs)

Excess adsorption isotherms of acetonitrile and methanol from water were measured on eight commercial columns. Columns used in this study represent the latest examples in column development and include three different poroshell columns (Kinotex C18, Ascentis C18, and Halo C18) as well as conventional columns with significantly different adsorbent geometries (Allure C18, YMC C18) and various hybrid-silica columns (Gemini C18, Xterra C18, and XBridge C18). Comparison of the excess adsorption isotherms measured on all these columns and expressed in surface-specific form demonstrated significant similarity of the adsorption properties of all columns, which allows the introduction of the Standard Excess Adsorption …

Thermocatalytic Plasma-Assisted Dry Reforming Of Methane Over Ni/Al2o3 Catalyst, Tyler Wong

Seton Hall University Dissertations and Theses (ETDs)

Plasma catalysis is an advantageous approach that combines the effects of plasma with the enhancements of a catalyst. By utilizing a nickel catalyst in the plasma discharge zone of a dielectric barrier discharge (DBD), it can give an enhancement to the electrical field, boost microdischarges, and increase conversion and selectivity rates of CH₄ and CO₂ in the dry reforming of methane (DRM) reaction.

Industrial application of nickel catalysts in DBD Plasma DRM process are limited by poor stability, which is caused by the sintering of active metal particles and coke deposition on the catalyst surface. In this work, …

Investigating The Diffusion Of Solid Yttria Into Solid Zirconia For The Formation Of Yttria Stabilized Zirconia, Logan Thomas Ockershausen

Seton Hall University Dissertations and Theses (ETDs)

A molecular dynamics simulation of yttria-stabilized zirconia (YSZ) is reported in order to analyze the diffusion of the oxygen atoms from the yttria into the zirconia from an initial structure containing a layer of yttria on zirconia. The simulation was performed starting from a pure zirconia slab which was amorphized at the surface followed by placing a slab of yttria on top and a vacuum layer above that. The yttria/zirconia system was simulated at increasing temperatures to 1500K under canonical (NVT) constraints for 6.98 ns until the yttrium atom diffusion was found to occur. The final run was analyzed for …

Microwave Synthesis And Photophysical Characterization Of Heteroleptic Iridium Complexes For Applications In Oleds And Lecs, Allyson Dixon

Seton Hall University Dissertations and Theses (ETDs)

A series of heteroleptic, iridium-based ionic transition metal complexes (ir-iTMCS), with the purpose to serve as potential components of OLED and LEC devices, were synthesized through a green, combinatorial-based approach. This work utilized a microwave reactor in order to bring our research into closer alignment with the tenets of green chemistry. The aim of this research was to assess the effects of structural differences, specifically steric crowding, on the photophysical characteristics of the complexes. The radiative quantum efficiencies (Φ_f) and excited state lifetimes (τ ) of the series of Ir-iTMCs were investigated. The rates of radiative (k_{r …}

Photoacid-Catalyzed C–C And C–O Bond Formation And The Synthesis Of Triazole - Containing Bis(Indolyl)Methanes, Jason Saway

Seton Hall University Dissertations and Theses (ETDs)

From photosynthesis to transition metal-type photocatalysts, the conversion of light energy into chemical energy is a fundamental process in chemistry. While photochemistry is not new to the world of science, there has been a renewed interest in the field, specifically with the use of photocatalysts. There is a wide variety of compounds that function as photocatalysts, ranging from transitions metal complexes, organic dyes, and photoacids. Photoacids, which have typically been used for polymer synthesis and the pH modulation of biological systems and have recently gained popularity due to their catalytic potential. These compounds offer an efficient, cost-effective way to conduct …

Photoisomerizable Membrane Active Peptides, Cristina Ventura

Seton Hall University Dissertations and Theses (ETDs)

Membrane active peptides (MAPs) bind and partition into the cell membrane thus causing permeabilization. Many α-helical membrane active peptides contain central proline residues that distinguish the hydrophobic and hydrophilic faces of the helix. The proline induces a bend that produces a helix-hinge-helix motif. Mutation of these proline residues has a significant effect on the activity of the MAP. Azobenzene is a photoisomerizable molecule that switches from its trans to cis isomer upon excitation with ultraviolet (UV) light and from its cis to trans isomer upon excitation with visible light (VL). In this work it is hypothesized that the hinge function …

Advances In Structure Elucidation Of Small Molecules And Peptides By Nuclear Magnetic Resonance Spectroscopy And Mass Spectrometry, Ryan D. Cohen

Seton Hall University Dissertations and Theses (ETDs)

This dissertation reports on improvements in nuclear magnetic resonance (NMR) and mass spectrometry (MS) structure determination methods of organic compounds, with particular focus on challenging cyclic peptides. A recent and important innovation in NMR spectroscopy is the combination of theoretical property predictions, such as chemical shifts, using density functional theory (DFT) to aid in challenging NMR structure assignments, such as determination of regio- and stereo-configurations. In the first part of this thesis, a comprehensive benchmark study of DFT chemical shift prediction methods was performed using experimental NMR data collected from 50 well curated compounds, which was referred to as the …

Visible Light Photoacid Generator Catalyzed Michael Additions & In-Situ Photoredox Generated Carbocation Catalysis, Zena M. Salem

Seton Hall University Dissertations and Theses (ETDs)

Proton transfer is essential in many natural and chemical processes, and photoacids that undergo proton dissociation or generation upon photoirradiation can be beneficial for use in acid-sensitive reactions. This work describes the use of photoacid generators (PAGs) as tools for organic synthesis, generating strong acids upon light absorption catalyzing Michael addition reactions. Specifically, visible-light-induced PAGs were used to facilitate the 1,4-conjugate addition between indoles and vinyl ketones. Furthermore, carbocations have gained attention as Lewis acid catalysts in a variety of reactions providing good selectivity and yields. We also demonstrate the viability of in-situ photoredox-generated carbocation catalysis in the context of …

Rational Design, Synthesis And Biology Of Immunostimulatory Peptides, Nelson Casanova

Seton Hall University Dissertations and Theses (ETDs)

This dissertation reports the design, synthesis, characterization, and biological studies of three uniquely structured peptides, derived from ubiquitinated multiple myeloma proteins and ubiquitinated B7H6 ligand. The peptides were made into linear or branched shapes, with the branched peptides containing both major histocompatibility complex (MHC) class two and NKp30 binding motifs properties in one peptide. This results in an immunocytotoxic response (via cytokines and chemokines) of both natural killer cells and cytotoxic T lymphocytes (CTLs). These shapes were determined for data comparison but also to increase cytokine proliferation, the shapes help with healthy cell aviation. Thus, the linear monomer (contains a …

Surface Characterization Of Mixed-Mode Adsorbents Using Bet C-Constant Energy Scale, Dinah C. Lee

Seton Hall University Dissertations and Theses (ETDs)

Mixed-mode chromatography is a chromatographic method in which solutes interact with stationary phase through more than one interaction mode or mechanism. It is because of these multiple complex interactions, which makes it difficult to predict chromatographic behavior of analytes on Mixed-mode columns. In order to fully understand the retention mechanisms on Mixed-mode columns, the packing material properties must be well characterized since each characteristic may contribute to the overall chromatographic performance of the column. Many non-chromatographic and chromatographic techniques are available to characterize and compare Mixed-mode columns in terms of their interaction abilities, retentivity, surface chemistry, chemical properties and geometry. …

Evaluation Of Yttrium Stabilized Zirconium Thin Films With Secondary Ion Mass Spectrometry, Jeff Serfass

Seton Hall University Dissertations and Theses (ETDs)

Fuel Cells using solid oxides for the electrolyte material, or Solid Oxide Fuel Cells (SOFCs), can operate at high temperatures and have many benefits when compared to other electrolyte material-based fuel cells. SOFCs can, however still have problems when operating at these high temperatures. (~1,000 degrees Celsius) At high temperatures, the SOFC electrolyte resistivity goes up making the ionic conductivity decrease and therefore a loss of performance. The inclusion of low level Yttria to Zirconium Oxide (the electrolyte material) has been known to help reduce the resistivity at high operating temperatures. In this study, a series of Yttria stabilized Zirconium …

Extending The Application Of Polyol-Induced Extraction For The Analysis Of Glucocorticoids And Nsaids In Water Using Uhplc-Ms/Ms, Shipra Patel

Seton Hall University Dissertations and Theses (ETDs)

Polyol induced extraction (PIE) is an extraction technique developed and patented by Sowa Jr., Murphy, and Deshpande at Seton Hall University as a method of removal of water from acetonitrile. PIE is a technique that separates water from a mixture containing an organic liquid and water by adding a polyol to the mixture that leads to phase separation of aqueous and organic phase. The goal of this work was to extend the application of PIE and to demonstrate that PIE can be an alternative method for extraction of glucocorticoids and non-steroidal anti-inflammatory drugs (NSAIDS) which then can be analyzed using …

Using Thermodynamics To Evaluate Stationary Phase Polarity In Gas Chromatography- A New Look, Hetal R. Rana

Seton Hall University Dissertations and Theses (ETDs)

Abstract

Gas chromatography is a separation method in which the components of a sample partition between a gaseous mobile phase (carrier gas) and a solid or liquid stationary phase. The stationary phase is usually a polymer coated or chemically bonded to a solid support on the column wall and its function is to separate different components, based on their relative vapor pressure and their intermolecular interactions with the stationary phase. If the analyte polarity is similar to the stationary phase polarity, then the retention time increases because the intermolecular interactions are stronger and if the polarities are different then the …

Plasma Agriculture: Characterization Of Dbd Plasma Jet And Analysis Of Effects When Treated On Sweet Basil (Ocimum Basilicum), William Davis

Seton Hall University Dissertations and Theses (ETDs)

Plasma agriculture is an increasingly diverse field, where effects of nonthermal or cold plasma are measured by their influence on plant physiology and growth rate. Effects range from sterilization, germination, increased growth rate, cell metabolism, and so forth. This study aims to investigate the understanding of the generation of specific reactive oxygen and nitrogen species (RONS) from a nonthermal atmospheric DBD helium-based plasma jet and identify quantifiable effects that can directly translate to different applications related to plasma agriculture. Basil plants were separated into treated and control groups and grown hydroponically. The treated plants received a 30 second exposure treatment …

Theranostic Applications Of Sirna Bioconjugates In Cancer Detection And Treatment, Sunil S. Shah

Seton Hall University Dissertations and Theses (ETDs)

Abstract

The emerging field of RNA nanotechnology has led to rapid advances in the applications of RNA in chemical biology, medicinal chemistry, and biotechnology. At the forefront of its utility is the ability to self-assemble multiple siRNAs into nanostructure formulations capable of targeting selected oncogenes and potentiating the gene therapy of malignant tumors. Self-assembled siRNA integrates multiple siRNAs within a single molecular platform for silencing multiple oncogenic mRNA targets with high precision and efficacy to potentially induce cancer cell apoptosis through the RNA interference (RNAi) pathway. Furthermore, the conjugation of siRNA self-assemblies with bio-active probes results in multi-functional theranostic (therapy+diagnostic) …

Investigations Into Effects Of Modified Prolines On Cis-Trans Isomers And Polypeptide Secondary Structure & Prediction Of Spectroscopic Properties Of Phthalonitriles For Characterization, Jeffrey Raab

Seton Hall University Dissertations and Theses (ETDs)

Proline is a unique amino acid because it is the only amino acid whose side chain wraps around and bonds back to the peptide backbone. This ring shape helps proteins form conformations which would otherwise not be possible such as hairpin turns. The cis/trans isomerization of the peptide bond between the preceding amino acid (X_aa) and Proline is important in determining how the secondary structure folds. Thus, being able to control the cis/trans isomerization is important when a specific conformation is desired; Proline can be modified to get make the equilibrium shift whichever way is needed. The modifications …

Fluorinated Phthalonitriles And Phthalocyanines: Synthesis And Spectroscopic Properties, Marius Pelmus

Seton Hall University Dissertations and Theses (ETDs)

Since their discovery at the beginning of the 20^th century, phthalocyanines (Pc) have come a long way; today they are replacing the porphyrins (natural products) in most of their applications. The functionalization of the organic macrocycle, the use of different metals, and the change of the axial ligands resulted in Pc applications in a wide range of fields, ranging from photochemistry, paints, catalysis, to fuel cells and cosmetic products.

In Dr. Gorun’s group was developed a series of electron-deficient Pcs that benefit from a Teflon-like chemical shield, meant also to break the π-π interactions, namely the F₆₄PcM …

Investigation Of The Chemical Kinetics In An Atmospheric Cold Plasma Towards Co2 Conversion, Daniel Piatek

Seton Hall University Dissertations and Theses (ETDs)

Hydrogenation of carbon dioxide (CO2) to methanol (CH3OH) is a promising route for utilization of excess and residual CO2. The conversion of CO to methanol is a well-developed process but the ability to use CO2 as a feed gas still requires high pressures (30-300 atm) to attain conversion. In this work, the hydrogenation of CO2 is explored using H2O as well as H2 in an atmospheric pressure nonthermal (cold) plasma created with a dielectric barrier discharge (DBD) reactor. Different gas mixtures such as argon (Ar) and helium (He) are used to understand their interactions in the process of CO2 hydrogenation. …

Characterization Of A Novel Double Cooled Electrode Dbd Reactor For Ozone Generation, Gustavo Duarte

Seton Hall University Dissertations and Theses (ETDs)

The Dielectric Barrier Discharge (DBD) is used to generate atmospheric or higher-pressure non-thermal plasmas and has found various commercial applications such as in industrial large-scale ozone generation. Ozone (O₃ ) is a powerful chemical reactant that is used to kill bacteria, to deodorize and to perform water purification. The effectiveness of the DBD reactors depends on the electrode arrangements, gap lengths, dielectric materials, operating gases and feed gas quality to name a few. However, the production of O₃ is heat sensitive. In order to prevent O₃ destruction thermal cooling of the DBD is needed. The industry approach …

D-Orbital Occupancy Of Transition Metal Oxides By X-Ray Absorption Near Edge Structure (Xanes), Eric Kurywczak

Seton Hall University Dissertations and Theses (ETDs)

XANES L₂ and L₃-edge X-Ray Absorption Near Edge Spectra (XANES) for 4d and 5d row transition metals (TM) oxides are assumed to be directly reflecting unoccupied d orbitals influenced by the local symmetry of the metal ion. XANES L₂- and L₃-edge data analysis through non-linear curve fitting allows for a unique, efficient look at the structural eccentricities of transition metal oxides. In this way it is possible to determine the oxidation state of a material as well as its site symmetry. We have used non-linear least-squares fitting across the near-edge region …

Density Functional Theory Calculations Of Al Doped Hafnia For Different Crystal Symmetry Configurations, Joshua Steier

Seton Hall University Dissertations and Theses (ETDs)

Dogan et al.[1], investigated the causes of ferroelectricity in doped hafnia using ab initio methods. Similarly, we investigated the stability of Al doped hafnia using quantum mechanical methods.

There are many different phases of Hafnia: monoclinic, tetragonal, cubic and orthorhombic. Starting with the monoclinic phase of Hafnia, Hafnia undergoes phase transitions which result in different space groups. The temperature at which the tetragonal phase is induced is 2000 K and cubic phase is induced at 2900 K[1]. Different dielectric constants vary from phase to phase. The average dielectric constants are highest for the cubic and tetragonal phases. In order to …

Electrical And Chemical Characterization Of A Helium-Air Non-Thermal Atmospheric Pressure Plasma Jet, Adam Zandani

Seton Hall University Dissertations and Theses (ETDs)

Plasma is one of the most complicated, yet promising fields in physics due to its high efficiency and multitude of crucial applications such as biological sterilization, polymer modification, surface treatments, etching, agriculture, and facilitation of selective catalytic processes to name a few. With these advantages, mysteries still remain. With this in mind, in order to accurately gauge the total influence of the plasma applied in various processes, understanding what is being produced and how the production occurs is vital. To understand this, optical emission spectroscopy was used to gauge how the species generated are influenced by operation parameters such as …

Surface Chemistry And Surface Properties Of Energetic Nitrocellulose (Nc), Henry Grau

Seton Hall University Dissertations and Theses (ETDs)

This research describes an investigation into the wettability of nitrocellulose (NC), most importantly to nitroglycerin (NG), which are key components of formulations used to propel military ammunition. NG demonstrates complete wetting of NC and, overtime, NG sweats on the NC surface and leaks out. The leaking out of NG from the solid formulation is a known cause of fires and explosions resulting from storage. The origin of this research is inspired by the need to engineer a solution to leakage problems of energetic plasticizer in NC based propellant. While searching for a viable material for a specific application, we journeyed …

Performance Of Nitrogen As A Carrier Gas In Capillary Gas Chromatography Using A Thin Film Column, Brittany A. Handzo

Seton Hall University Dissertations and Theses (ETDs)

Gas chromatography (GC) is one of the most widely used analytical techniques for the separation and analysis of volatile compounds. Solids, liquids, and gases, organic and inorganic materials, and large molecular weight compounds can all be analyzed via this technique. Gas chromatographic separations are fast, accurate, and reliable. One of the reasons why these separations are so efficient is because of the carrier gas. The purpose of the carrier gas is to carry the injected sample through the column. It is known as the mobile phase and does not interact chemically with the sample. Common carrier gases include helium, hydrogen, …

Organic-Inorganic Hybrid Composites: Superhydrophobic Polymer Coatings With Photoreactive Perfluorinated Phthalocyanines, Abdul Azeez

Seton Hall University Dissertations and Theses (ETDs)

ABSTRACT

We report partly fluorinated and silicon-based polymers that incorporate inorganic/organic materials capable of generating reactive oxygen species (ROS) using only visible light and air. Polyvinylidene fluoride (PVDF), which incorporated a known perfluorinated phthalocyanine photosensitizer, F₆₄PcZn, supported on silicon and titanium oxides was further modified via chemical surface roughening to exhibit enhanced hydrophobicity when used as a coating. Water contact angles as high as ~159° have been observed, vs. ~ 92° for the unmodified polymer. The polymer matrix, however, does not resist the ROS it produces as evidenced by spectroscopic and SEM data. A polysiloxane matrix was similarly …

Expanding The Toolbox With Site-Specific Methods Of Bioconjugation, Tiauna S. Howard

Seton Hall University Dissertations and Theses (ETDs)

Bioconjugation is an important tool for studying complex biological systems, with site-specificity being the major challenge. Reactions based on amino acid derived organocatalysts have been widely used in organic synthesis, particularly for the asymmetric synthesis of small molecules but this concept has not been vastly explored on biomolecules. To combat these limitations, two chemical strategies are developed to effectively attach synthetic molecules site specifically to proteins. First, a protein modification technique based on conjugation at a non-native functional handle, an aldehyde or ketone, is developed. This functional handle is chemically introduced onto the biomolecules before undergoing the organocatalyzed aldol reaction, …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Side Chain Modifications To Improve Peptide Structure–Activity Relations, Neelam Lahankar

Seton Hall University Dissertations and Theses (ETDs)

While natural peptides, are ideal starting points for peptide-based drug design and development, they suffer from high conformational instability, which results in susceptibility to proteolytic degradation and poor bioavailability. Peptidomimetics in recent years has helped circumvent these shortcomings by improving the pharmacological properties of polypeptides. Peptidomimetics contain essential elements (pharmacophores) that mimic a natural peptide or protein in 3D space and retain the ability to interact with the biological target producing the same biological effect. In contrast, they offer conformationally restricted structures, potentially minimizing cross-target interactions, which leads to better transport properties through biologic membranes and resistance to immune responses. …

Determination Of Polar Solvents By Static Headspace Extraction – Gas Chromatography (She-Gc), Michael Sithersingh

Seton Hall University Dissertations and Theses (ETDs)

ABSTRACT

The term “headspace” is defined as the vapor that forms above or around a liquid or solid sample in a closed container. Usually, the vapor is above the liquid or solid at the top of the container, hence the term headspace. Headspace sampling is a method for separating volatile materials that may be extracted from a more solid sample matrix and then analyzed using gas chromatography. Headspace extraction refers to the collection and analysis of the vapor phase in the container. The Static Headspace Extraction – Gas Chromatography (SHE-GC) technique has been used since the early days of Gas …

Fluorescently Labeled Sirnas And Their Theranostic Applications In Cancer Gene Therapy, Stephen David Kozuch

Seton Hall University Dissertations and Theses (ETDs)

Gene therapy has emerged as a promising precision nano-medicine strategy in the treatment of numerous diseases including cancer. At the forefront of its utility are the applications of short-interfering RNA (siRNA), that silence oncogenic mRNA expression leading to cancer cell death through the RNA interference (RNAi) pathway. Despite the therapeutic potential, siRNAs are limited by poor pharmacological properties, which has hindered their translation into the clinic. Recent studies, however, have highlighted the applications of modified siRNAs, including the use of fluorescent probes and siRNA nanostructures in cancer detection and treatment. The siRNAs reported in this thesis are designed to target …