Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Life Sciences (7)
- Engineering (4)
- Kinesiology (4)
- Forest Sciences (3)
- Physics (3)
-
- Chemical Engineering (2)
- Oceanography and Atmospheric Sciences and Meteorology (2)
- Atmospheric Sciences (1)
- Biomedical (1)
- Biomedical Engineering and Bioengineering (1)
- Electrical and Computer Engineering (1)
- Environmental Chemistry (1)
- Environmental Sciences (1)
- Materials Science and Engineering (1)
- Medicine and Health Sciences (1)
- Publication Year
- Publication
- Publication Type
Articles 61 - 90 of 199
Full-Text Articles in Chemistry
Synthesis Of 5-Methyl-3-Phenyl-1,3,4-Oxadiazol-2(3h)-One Derivatives By Electrophilic Aromatic Substitution, Amanda Solis Conde
Synthesis Of 5-Methyl-3-Phenyl-1,3,4-Oxadiazol-2(3h)-One Derivatives By Electrophilic Aromatic Substitution, Amanda Solis Conde
Browse all Theses and Dissertations
An important research element in the Turnbull laboratory has been the one-pot synthesis of 5-methyl-3-phenyl-1,3,4-oxadiazol-2(3H)-one from sydnone. The present study reexamined the reaction of 5-methyl-3-phenyl-1,3,4-oxadiazol-2(3H)-one with electrophiles and optimized methods for synthesis of oxadiazolinone derivatives. Further the oxadiazolinone derivatives were reacted with electrophiles to better comprehend the donating ability of the oxadiazolinone ring system in general with the expectation that the oxadiazolinone ring system is a slightly donating system. Additionally, when the structure assignment of the oxadiazolinone derivative was ambiguous, the corresponding oxadiazolinone or it’s isomer was synthesized from the appropriate sydnone to validate or refute the suggested structure. The …
Redox-Active Silver N-Heterocyclic Carbene Complexes: A Dual Targeting Antibacterial Drug, Kotiba Malek
Redox-Active Silver N-Heterocyclic Carbene Complexes: A Dual Targeting Antibacterial Drug, Kotiba Malek
Browse all Theses and Dissertations
Bacterial resistance to current [beta]-lactam antibiotics necessitates new therapeutic approaches. Silver-based drugs offer a promising alternative because of their antibacterial properties and minimal bacterial resistance. However, many silver-based antibacterial drugs rapidly release silver ions, limiting the bioavailability of silver ions for a longer period of time. Recently, N-heterocyclic carbenes (NHC) containing silver complexes have become a popular subject of research due to their versatility and the slow release of silver ions under biological conditions. To further enhance the efficacy of silver-NHC drugs, we fused redox-active substituents such as naphthoquinone and ferrocenes to NHCs. Both naphthoquinone and ferrocenes have been shown …
A Lc-Ms/Ms-Based Method For The Multiplex Detection Of 24 Fentanyl Analogs And Metabolites In Whole Blood At Sub Ng Ml-1 Concentrations, Kraig Edward Strayer
A Lc-Ms/Ms-Based Method For The Multiplex Detection Of 24 Fentanyl Analogs And Metabolites In Whole Blood At Sub Ng Ml-1 Concentrations, Kraig Edward Strayer
Browse all Theses and Dissertations
The United States and numerous other countries worldwide are currently experiencing a public health crisis due to the abuse of illicitly manufactured fentanyl (IMF) and its analogues. This manuscript describes the development of a liquid chromatography-tandem mass spectrometry-based method for the multiplex detection of N = 24 IMF analogues and metabolites in whole blood at concentrations as low as 0.1-0.5 ng mL-1. These available IMFs were fentanyl, norfentanyl, furanyl norfentanyl, remifentanil acid, butyryl norfentanyl, remifentanil, acetyl fentanyl, alfentanil, AH-7921, U-47700, acetyl fentanyl 4-methylphenethyl, acrylfentanyl, para-methoxyfentanyl, despropionyl fentanyl (4-ANPP), furanyl fentanyl, despropionyl para-fluorofentanyl, carfentanil, (±)-cis-3-methyl fentanyl, butyryl fentanyl, isobutyryl fentanyl, sufentanil, …
Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov
Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov
Michigan Tech Publications
Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed …
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Browse all Theses and Dissertations
One goal of the Turnbull research group has been the synthesis of dihalogenated arylsydnones; i.e. sydnones with halogen substitution on the sydnone ring itself, as well as at the position on the aryl ring ortho to the sydnone. Further, it has been of interest to explore the reactivity of these compounds, once obtained. The present study examined the synthesis of 4-iodo-3-(2-iodoaryl)-, or “diiodo”, and 4-bromo-3-(2-bromoaryl)-, or “dibromo”, sydnones and the reactions of these compounds with Na2SO3 (sodium sulfite) and NaBH4 (sodium borohydride) to create a better understanding of the reactivity of diiodo and dibromo arylsydnones in general. Additionally, the reactivity …
Hydrothermal Atomic Force Microscopy Investigation Of Barite Growth: The Role Of Spectator Ions In Elementary Step Edge Growth Kinetics And Hillock Morphology, Sarah A. Jindra
Browse all Theses and Dissertations
To better understand the role of spectator ions in barite growth, the kinetics of step edge growth on barite (001) surfaces were studied under various salt solutions. Hydrothermal Atomic Force Microscopy (HAFM) was used to investigate the effect of background electrolytes (NaCl, NaBr and NaNO3) as a function of saturation index and ionic strength (I) on barite growth sourced at dislocations at 108 oC. Results show that hillock morphology is affected by I, as well as type of anion, where the prevalence of steps aligned on the [010] direction is highest under Cl- …
Toward The Synthesis Of Functionalized Poly (Ether Ether Ketone): Monitoring The Meta-Fluorine Displacement In 3,5,4’-Trifluorobenzophenone, Giovanni Covarrubias
Toward The Synthesis Of Functionalized Poly (Ether Ether Ketone): Monitoring The Meta-Fluorine Displacement In 3,5,4’-Trifluorobenzophenone, Giovanni Covarrubias
Browse all Theses and Dissertations
The synthesis of functionalized, linear poly (ether ether ketone), tailored to be semi-crystalline and soluble in a variety of organic-solvents was explored. Nucleophilic aromatic substitution was a chemical reaction method used to condense 3,5,4’-trifluorobenzophenone (TFK) with four different phenols at its para-positioned carbon-fluorine site: 4-methoxyphenol, 3-aminophenol, 4-bromophenol, and m-cresol. Further poly-condensation of functionalized TFK occurred at the meta-positioned carbon-fluorine sites with 4,4’-Bis[4-hydroxyphenoxy] benzophenone (Big A2) and 4,4’-difluorobenzophenone at molar equivalents of 1 to 0.5, respectively. The reaction afforded products that became insoluble in solvents needed for nuclear magnetic resonance spectroscopic (e.g. DMSO-d6) analysis. The lack of desirable compounds compelled the …
Computational And Experimental Investigations Concerning Rare Gas And Dpal Lasers And A Relaxation Kinetics Investigation Of The Br2 + 2no = 2brno Equilibrium, Joel R. Schmitz
Browse all Theses and Dissertations
This research contains four different research projects, the first an educational project introducing hydrogen bromide and deuterium bromide (HBr/DBr) and carbon monoxide (CO) as viable options for infrared vibration-rotation spectroscopy at 0.125 cm-1 or 0.5 cm-1 resolution in the teaching laboratory. The second project involved determining the spectral shifts of lanthanide fibers for diode-pumped alkali laser (DPAL) applications. Spectral shifts of lanthanides were determined using UV-VIS-NIR absorbance spectroscopy and laser-induced fluorescence (LIF). The third project entailed computing Ar* atomic energy levels and the potential energy curves of Ar*+He laser systems arising from 3p54s1 and 3p …
The Synthesis Of 3,5-Difluorobenzophenone Derivatives And Their Corresponding Peek Copolymers, Rachael Stuck
The Synthesis Of 3,5-Difluorobenzophenone Derivatives And Their Corresponding Peek Copolymers, Rachael Stuck
Browse all Theses and Dissertations
Poly(aryl ether ketone)s (PAEK) are high performance thermoplastics, which are chemically robust, semi-crystalline, and stable at high temperatures. Of the family of PAEKs, poly(ether ether ketone) (PEEK) is a well-known semi-crystalline thermoplastic widely used for electronics, energy, industrial, and medical applications due to its resistance to solvents, radiation, heat, and other environmental factors. The traditional PEEK is prepared from 4,4’-difluorobenzophenone (2) and disodium hydroquinone. However, a challenge is processability, since due to its highly crystalline nature, PEEK possesses very limited solubility. An approach to solve these issues is to pre-functionalize PEEK polymers synthesized by nucleophilic aromatic substitution from 3,5-difluorobenzophenone (1) …
Synthesis Of Alkyl Substituted Phenylated Poly(Ether Ether Ketone Ketone)S, Matthew Cerone
Synthesis Of Alkyl Substituted Phenylated Poly(Ether Ether Ketone Ketone)S, Matthew Cerone
Browse all Theses and Dissertations
A phenylated bis(fluorobenzoyl) monomer, 5-hexyl-2,3-diphenyl-1,4-bis(fluorobenzoyl)benzene, was synthesized via a four-step process. The first three compounds synthesized were diethyl 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxylate, 5-hexyl-1,4-bis(hydroxymethyl)-2,3-diphenylbenzene and 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxaldehyde. The final step involved the reaction of the Grignard formed from p-bromofluorobenzene with the dialdehyde to yield a diol intermediate which was oxidized to the bis(fluorobenzoyl) monomer by use of a Jones oxidation. The monomer was polymerized by nucleophilic aromatic substitution (NAS) with bisphenol-A, resorcinol, and hydroquinone in N-methyl-pyrrolidone (NMP) to yield novel, phenylated PEEKKs. The number-average molecular weights (Mn) for the polymers were found to be 35,700 g/mol, 34,800 g/mol and 28,000 g/mol, respectively and the weight-average …
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Browse all Theses and Dissertations
One goal of the Turnbull research group has been the synthesis of dihalogenated arylsydnones; i.e. sydnones with halogen substitution on the sydnone ring itself, as well as at the position on the aryl ring ortho to the sydnone. Further, it has been of interest to explore the reactivity of these compounds, once obtained. The present study examined the synthesis of 4-iodo-3-(2-iodoaryl)-, or "diiodo", and 4-bromo-3-(2-bromoaryl)-, or "dibromo", sydnones and the reactions of these compounds with Na2SO3 (sodium sulfite) and NaBH4 (sodium borohydride) to create a better understanding of the reactivity of diiodo and dibromo arylsydnones in general. Additionally, the reactivity …
Incorporation Of Indeno[2,1-C]Fluorenes Into Polymers Via Nucleophilic Aromatic Substitution, Nathaniel Brackett
Incorporation Of Indeno[2,1-C]Fluorenes Into Polymers Via Nucleophilic Aromatic Substitution, Nathaniel Brackett
Browse all Theses and Dissertations
A difluoro indeno[2,1-c]fluorene monomer was synthesized by a four-step process. The first compound synthesized by a two-step process was 2,5- bis(ethoxycarbonyl)-3,4-di(4-fluorophenyl)cyclopentadienone. The next two compounds synthesized were diethyl 2,3-bis(fluorophenyl)-5-hexylterephthalate and 2,3- bis(fluorophenyl)-5-hexylterephthalic acid. The final step involved an intramolecular Friedel-Crafts acylation of the terephthalic acid derivative to form 3,10-difluoro-5,8- dioxo-5,8-dihydro-6-hexylindeno[2,1-c]fluorene. The difluoro monomer was reacted in a series of nucleophilic aromatic substitution (NAS) polymerization reactions with bisphenol-A in N-methyl-pyrrolidone (NMP) in an attempt to form novel poly(ether ether ketone ketone)s containing the indeno[2,1-c]fluorene structure. Analysis of the product by NMR and TLC showed the reaction was unsuccessful and the difluoro …
Hydrothermal Atomic Force Microscopy Investigation Of Barite Growth: The Role Of Spectator Ions In Elementary Step Edge Growth Kinetics And Hillock Morphology, Sarah A. Jindra
Browse all Theses and Dissertations
To better understand the role of spectator ions in barite growth, the kinetics of step edge growth on barite (001) surfaces were studied under various salt solutions. Hydrothermal Atomic Force Microscopy (HAFM) was used to investigate the effect of background electrolytes (NaCl, NaBr and NaNO3) as a function of saturation index and ionic strength (I) on barite growth sourced at dislocations at 108 oC. Results show that hillock morphology is affected by I, as well as type of anion, where the prevalence of steps aligned on the [010] direction is highest under Cl- There is a modest increase in kinetic …
Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Amira Moayad Alsenbel
Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Amira Moayad Alsenbel
Browse all Theses and Dissertations
Limited macroinvertebrate biodiversity in Lytle Creek that runs through downtown Wilmington, Ohio has been documented over decades with the lowest in Lytle Creek at Sugar Grove Cemetery. Lytle Creek, a tributary of the Little Miami River, is a conduit for storm water and wastewater from an airport, downtown storm water with input from local businesses, and a wastewater treatment plant. This study was conducted to see if heavy metal pollution in the sediment, water quality, and Escherichia coli (E. coli) could be contributing factors in reduced macroinvertebrate populations. Eight sites were chosen for sediment sampling to measure trace metals. Mercury …
Synthesis And Reactivity Of Sydnone Derived 1,3,4-Oxadiazol-2(3h)-Ones, Jonathan Michael Tumey
Synthesis And Reactivity Of Sydnone Derived 1,3,4-Oxadiazol-2(3h)-Ones, Jonathan Michael Tumey
Browse all Theses and Dissertations
5-(Bromomethyl)- and 5-(trichloromethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-ones were synthesized from bromocarbonyl hydrazine intermediate salts and acid halides to provide further evidence for our proposed mechanism for the formation of oxadiazolone ring systems from sydnones. 5-(Bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was a compound of interest due to its SN2 possibilities and three potential sites of diversification. The procedure to synthesize 5-(bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was developed originally by Madaram in the Turnbull lab, but was further optimized in the present work by altering the time, temperature and stoichiometric equivalents of the acid halide to provide high purity and excellent yields of the product. While this compound of interest had been isolated and …
Chemical Applications In Techniques Of Emerging Significance: Nanoparticle Transformation In Mitochondria And Relative Tautomer Populations In Cellular Automata, Gregory Arland Bowers
Chemical Applications In Techniques Of Emerging Significance: Nanoparticle Transformation In Mitochondria And Relative Tautomer Populations In Cellular Automata, Gregory Arland Bowers
Browse all Theses and Dissertations
Two techniques of emerging importance were used to study different biochemical phenomena: the fate of silver nanoparticles in Vero 76 African green monkey kidney cell mitochondria, and the effect of pH on tautomer ratios using cellular automata. In the first area of research Vero 76 Africa green monkey kidney cells were incubated with silver nanoparticles (AgNP) and ionic silver (Ag+). After 24 hours the cell mitochondria were harvested, then processed with CPE-TFF and ICP-OES. The initial AgNP incubation formed 52.9% ± 15.5% AgNP and 29.9% ± 4.0% Ag+, while the ionic silver incubation formed 9.5% ± 0.9% AgNP and 60.6% …
The Synthesis And Characterization Of Double And Triple Tethered Indeno[2.1-C]Fluorendiones, Daniel K. Greene
The Synthesis And Characterization Of Double And Triple Tethered Indeno[2.1-C]Fluorendiones, Daniel K. Greene
Browse all Theses and Dissertations
A series of terephthalate esters was synthesized via a Diels-Alder reaction between 2,5-dicarboethoxy-3,4-diphenylcyclopentadienone and various alkynes in order to study reaction conditions necessary to synthesize poly(indeno[2,1-c]fluorene-5,8-dione)s. Diethyl 2,3-diphenyl-5-butylterephthalate, 1,4-bis(3,4-diphenyl-2,5-di(ethoxycarbonyl) phenyl)butane and N,N,N-tris(3,4-diphenyl-2,5-di(ethoxycarbonyl)phenylmethyl)amine were synthesized and characterized by IR, 1H NMR, 13C NMR, 13C NMR DEPT135 spectroscopies as well as elemental composition. Hydrolysis conditions of the terephthalates using potassium hydroxide were also investigated. It was found that large stoichiometric equivalents of base coupled with reaction times over twenty-four hours afforded only partially hydrolyzed products. The synthesis of 6-butylindeno[2,1-c]fluoren-5,8-dione was successfully carried out by the sulfuric acid catalyzed, intramolecular, Friedel-Crafts cyclization of …
Green Chemistry: Progress And Barriers, Sarah A. Green
Green Chemistry: Progress And Barriers, Sarah A. Green
Michigan Tech Publications
Green chemistry can advance both the health of the environment and the primary objectives of the chemical enterprise: to understand the behavior of chemical substances and to use that knowledge to make useful substances. We expect chemical research and manufacturing to be done in a manner that preserves the health and safety of workers; green chemistry extends that expectation to encompass the health and safety of the planet. While green chemistry may currently be treated as an independent branch of research, it should, like safety, eventually become integral to all chemistry activities. While enormous progress has been made in shifting …
Poly(Arylene Ether Sulfone)S With Ammonium Groups Located On Pendent Phenyl Sulfonyl Moieties For Anionic Exchange Membranes, Trevor I. Schumacher
Poly(Arylene Ether Sulfone)S With Ammonium Groups Located On Pendent Phenyl Sulfonyl Moieties For Anionic Exchange Membranes, Trevor I. Schumacher
Browse all Theses and Dissertations
A series of poly(aryl ether sulfone)s with varying percentages of ammonium groups, located on truly pendent positions, was prepared and characterized. The initial polymers were prepared by nucleophilic aromatic substitution (NAS) polycondensation reactions of varying ratios of 3,5-difluoro-4'-methyldiphenylsulfone and 4,4'-difluorodiphenylsulfone, with bisphenol-A as the nucleophilic reaction partner. The tolyl groups in the resulting polymers were subjected to radical bromination with N-bromosuccinimide, followed by amination with three different amines: trimethylamine, dimethylhexadecylamine, and N-methylimidazole. The polymers were characterized by 1H and 13C NMR spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. With the exception of the 100% functionalized polymers, tough films were observed …
Vespucci: A Free, Cross-Platform Software Tool For Spectroscopic Data Analysis And Imaging, Daniel Patrick Foose
Vespucci: A Free, Cross-Platform Software Tool For Spectroscopic Data Analysis And Imaging, Daniel Patrick Foose
Browse all Theses and Dissertations
Vespucci is a software application developed for imaging and analysis of hyperspectral datasets. Vespucci offers several advantages over other software packages, including a simple user interface, no cost, and less restrictive licensing. Vespucci incorporates several analysis techniques including univariate imaging, principal components analysis, partial-least-squares regression, vertex components analysis and k- means clustering. Additionally, Vespucci can perform a number of useful data-processing operations, including filtering, normalization, baseline correction, and background subtraction. Datasets that consist of spatial or temporal data with a corresponding digital signal, including spectroscopic images, mass spectrometric images, and X-ray diffraction data can be processed in this software. The …
Routes To 1,3,4 - Oxadiazol-2(3h)-Ones, Karunakar Reddy Madaram
Routes To 1,3,4 - Oxadiazol-2(3h)-Ones, Karunakar Reddy Madaram
Browse all Theses and Dissertations
Various 1,3,4-oxadiazol-2(3H)-ones were synthesized by reaction of the bromocarbonylhydrazine salt(35) obtained from treatment of 4-bromo-3-phenylsydnone(34) with HCl with the corresponding acid chlorides in DME. The structures were confirmed by their physical, analytical and spectral data (IR, GC/MS, 1H and 13C NMR and CHN analysis). In general these compounds were synthesized in good to excellent yields and it is planned to continue exploration of their chemical behavior as a guide to their potential antimicrobial activity. As an initial approach to the synthesis of the desired 1,3,4-oxadiazol-2(3H)-ones, the starting material, 3-phenylsydnone, was prepared in 2 steps from commercially available N-phenylglycine in good …
Synthesis, Characterization, And Polymerization Of Sulfonamide Based Bifunctional Monomers, Brady Hall
Synthesis, Characterization, And Polymerization Of Sulfonamide Based Bifunctional Monomers, Brady Hall
Browse all Theses and Dissertations
A series of bifunctional monomers based on N,N-diallylbenzenesulfonamides with varying groups on the benzene moiety were investigated. The main goal of this project was to polymerize these monomers using radical and acyclic diene metathesis (ADMET) polymerization methods to polymerize through the allyl groups, and nucleophilic aromatic substitution (SNAr) to polymerize through the fluorine groups on the phenyl ring. Using phenyl substituted benzenesulfonyl chloride derivatives as a starting material, a series of N,N-diallylbenzenesulfonamide derivatives were prepared. The ADMET and radical cyclopolymerizations were monitored by 1H NMR spectroscopy, observing the disappearance of signals for the allyl groups in both, and the appearance …
Synthesis And Characterization Of Functionalized Poly(Arylene Ether Sulfone)S Using Click Chemistry, Kavitha Neithikunta
Synthesis And Characterization Of Functionalized Poly(Arylene Ether Sulfone)S Using Click Chemistry, Kavitha Neithikunta
Browse all Theses and Dissertations
Poly(arylene ether sulfone)s with pendent aryl iodide group was successfully synthesized via Nucleophilic aromatic polycondensation of 1-(3,5-difluorophenyl sulfonyl)-4-iodobenzene using 4,4’-difluorodiphenylsulfone (DFDPS) and Bisphenol A in the ratio 25:75:100. Iodo monomer was prepared by reacting 3,5-difluorodiphenyl sulfone with N-iodo succinimide (NIS). Using GC/MS and NMR spectroscopy, the quantitative analysis was done to this monomer. Modification was done to iodo copolymer using sodium azide and copper sulfate as catalyst to form azide copolymer. Further modification of the azide copolymer to triazole copolymers via Click Chemistry using different alkynes such as 1-octyne, phenyl acetylene, propargyl alcohol and acetylenedicarboxylic acid. Polymers characterization was done …
Bioavailability And Transformation Of Silver Nanoparticles In The Freshwater Environment, Seth W. Brittle
Bioavailability And Transformation Of Silver Nanoparticles In The Freshwater Environment, Seth W. Brittle
Browse all Theses and Dissertations
The proliferation of silver nanoparticles (AgNPs) in consumer products and industrial applications has generated many environmental concerns since the chemistry of silver changes at the nanoscale and the very properties that make them desirable – their unique reactivity – may pose environmental risks. This dissertation addresses these concerns from three different angles. First, freshwater crayfish is demonstrated as a potential benthic indicator of Ag pollution since Ag accumulation depends on the form of Ag. The uptake and distribution of Ag (from AgNPs or Ag+) in tissue samples were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The hepatopancreas (1.5-17.4 …
Alkylenedioxy Containing Peek Polymers Containing Meta Linkages, James Uchenna Ohaeri
Alkylenedioxy Containing Peek Polymers Containing Meta Linkages, James Uchenna Ohaeri
Browse all Theses and Dissertations
The oxyalkylene containing, meta linked monomers 1,2-bis(3-(4-fluorobenzoyl)phenoxy)ethane, 1,3-bis(3-(4-fluorobenzoyl)phenoxy)propane, 1,4-bis(3-(4-fluorobenzoyl)phenoxy)butane, 1,5-bis(3-(4-fluorobenzoyl)phenoxy)pentane can be prepared by a three-step process starting with the dialdehydes (1,2-bis(3-formylphenoxy)ethane, 1,3-bis(3-formylphenoxy)propane, 1,4-bis(3-formylphenoxy)butane and 1,5-bis(3-formylphenoxy)pentane, respectively). Polymerization of the monomers with bisphenol-A gave soluble, thermally stable amorphous poly(ether ether ketone)s. The polymers exhibited molecular weights of (Mw/Mn) (21,841/ 8721) g/mol, (21,195/ 7569) g/mol, (9,107/ 2819) g/mol and (12,990/ 4723) g/mol, respectively. Thermal analyses of the polymers revealed Tgs of 112º, 106º, 92º and 91º, respectively and 5% weight losses under a nitrogen atmosphere of 389º, 410º, 411º and 414º, respectively.
Theoretical Estimation Of PkA'S Of Pyrimidines And Related Heterocycles, Rachael Ann Wessner
Theoretical Estimation Of PkA'S Of Pyrimidines And Related Heterocycles, Rachael Ann Wessner
Browse all Theses and Dissertations
Pyrimidines and related heterocycles are an important class of compounds with a wide variety of applications. As a result, there is great interest in the chemical properties of these compounds, specifically their pKa's. Despite the importance of these compounds their reported pKa's are often only approximations or are completely absent from literature. Experimentally measuring pKa's can be challenging, especially if the pKa is below zero. Alternatively, pKa's can be estimated computationally using a Quantitative Structure-Activity Relationship (QSAR). However, most of the compounds included in this study exist as two or more forms that arise from tautomerism. Tautomerism complicates the estimation …
An Investigation Of The Adsorption Behavior Between Silver Nanoparticles (Agnps) And Corundum (Α-Al2O3) At Environmental Ph Values Using Inductively-Coupled Plasma Optical Emission Spectroscopy (Icp-Oes) And Raman Spectroscopy, Kevin Andrew O'Neil
Browse all Theses and Dissertations
With the increased use of silver nanoparticles (AgNPs) in consumer products, the need to monitor their release into environmental soils has become critical. Although minerals make up a large component of soils, research on their interactions with AgNPs is still limited. Furthermore, the majority of the existing research focused on silica-based minerals rather than metal oxides, which is the second most abundant mineral type in the earth's crust. This study examined for the first time the aqueous interaction between the widely used, spherical Creighton AgNPs and a-corundum (a-Al2O3), a representative non-silica-based mineral, at environmentally relevant pH values (6-11). Samples were …
Design And Application Of Facile Routes To N-Heterocycle Functionalized Poly(Arylene Ether)S, Abraham K. Kemboi
Design And Application Of Facile Routes To N-Heterocycle Functionalized Poly(Arylene Ether)S, Abraham K. Kemboi
Browse all Theses and Dissertations
A series of 3,5-difluorinated systems, which are activated towards nucleophilic aromatic substitution (NAS) by the strongly electron withdrawing benzoxazole or benzothiazole groups, located meta to the fluorines were prepared and fully characterized. The monomers also carry various N-heterocyclic species on the non-fluorinated ring. The corresponding poly(arylene ether)s, some of which were copolymers with triphenylphosphine oxide-based monomers, were prepared via standard NAS polycondensation reactions. Incorporation of the monomers containing N-heterocycle units was determined by NMR spectroscopy. Characterization of the thermal properties was done using thermogravimetric analysis (TGA) and differential scanning (DSC). Most of the polymers displayed good film forming properties when …
Synthesis And Characterization Of Peek Analogues Utilizing 3,5- And 2,4-Difluorobenzophenone., Zachary Ewing
Synthesis And Characterization Of Peek Analogues Utilizing 3,5- And 2,4-Difluorobenzophenone., Zachary Ewing
Browse all Theses and Dissertations
Two routes to semi-crystalline, potentially functionalizable poly(ether ether ketone), PEEK, analogues were explored using varying percentages of 4,4’-difluorobenzophenone and either 3,5-difluorobenzophenone or 2,4-difluorobenzophenone as the electrophilic component in nucleophilic aromatic substitution polycondensation reactions with hydroquinone. PEEK analogues utilizing 3,5-difluorobenzophenone were carried out in a “one-pot” fashion and their properties were compared to the same materials prepared previously by a multi-step synthetic procedure. The use of 2,4-difluorobenzophenone led to completely new PEEK analogues. The polymers were characterized via NMR spectroscopy, Size Exclusion Chromatography, Thermogravimetic Analysis, and Differential Scanning Calorimetry. Molecular weight determinations showed the synthesized polymers to be of a variety …
Determination Of Atmospheric Particulate Matter Composition In The Dayton Metro Area, Saagar Mahendra Patel
Determination Of Atmospheric Particulate Matter Composition In The Dayton Metro Area, Saagar Mahendra Patel
Browse all Theses and Dissertations
Quartz filters from high-volume air samplers of particulate matter of a size less than 10 micrometers in diameter (PM10) located in Moraine and Yellow Springs, Ohio, were obtained from the Regional Air Pollution Control Agency and analyzed for levoglucosan, metals, and the EPA 16 priority polycyclic aromatic hydrocarbons (PAHs). Average concentration of levoglucosan increased as ambient temperature decreased. Winter concentrations of levoglucosan for Moraine and Yellow Springs were 39.41 ± 31.58 µg/g and 51.52 ± 27.44 µg/g, respectively, which is due to a greater amount of residential wood burning in the colder months. The concentration of biomass burning …