R-3 Repository :: Browsing by Author "Billups, W. Edward"

Browsing by Author "Billups, W. Edward"

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Bioorganic studies in Streptomyces species: Engineering the development of bioactive compounds
(2001) Johnson, Ewan Douglas; Billups, W. Edward
With the proliferation of multiresistent bacteria in clinical settings and the realization that these bacteria are even resistant to vancomycin. Efforts are currently underway to integrate both biosynthetic and genetic engineering techniques that promote the development of bioactive compounds elaborated by Streptomyces bacteria. The gram positive bacteria of the genus Streptomyces are well documented as having the ability to elaborate a wide range of structurally diverse compounds that have demonstrated varied bioactive properties. The research efforts in this dissertation conducted studies utilizing C-13 stable isotopes to elucidate the origins of C1', C2', C5' and C6' of octosyl acid A and polyoxin D, compounds elaborated in the fermentation broth of Streptomyces cacaoi var. asoensis. Protocols were developed for the genetic manipulation of Streptomyces threomyceticus and Streptomyces cacaoi var. asoensis. Genetic and molecular biology techniques were optimized to promote the conjugation and subsequent transfer of genetic material from gram negative Escherichia coli (S17-1) bacteria to the chromosome of gram positive bacteria Streptomyces threomyceticus. In addition, techniques were developed for the conjugation of S. cacaoi . var. asoensis. with E. coli. In this study, biosynthetic investigations demonstrated that the origin of 6' carbon of octosyl acid A and polyoxin D was pyruvate. It is postulated that pyruvate is converted to phosphoenolpyruvate before condensing with an analog of uridine aldehyde. Furthermore C-1' , C-2' and C-5' of the ribose moeity were derived from pyruvate after it was cycled through the pentose phosphate pathway. Application of directed biosynthesis to induce the production of new compounds resulted in the formation of a number of bioactive compounds. In this study, 5-hydroxymethylfurfural was identified, isolated and fully characterized. This compound, along with polyoxin D, was also shown to inhibit the growth of the test phytopathogenic fungus Cochliobolus miyabeanus.
Bond activation by photoexcited metal atoms
(1984) Gibbs, Suzanne; Billups, W. Edward; Parry, R. J.; Wilson, Lon J.
This work involves a study of ground state and photoexcited metal atoms reacting with ethylene, cyclopropane, acetylene and ethylene oxide in an argon matrix at 12°K. The reactions were followed by infrared spectroscopy. Ground state titanium atoms deoxygenate ethylene oxide to yield TiO and ethylene. Both iron atoms and dimers form adducts with ethylene oxide which when photoexcited yield ethylene and the iron oxides. Whereas titanium atoms fail to react with cyclopropane, photoexcited iron atoms and dimers insert into a carboncarbon bond of cyclopropane. Photoexcited iron atoms also insert into a carbon-hydrogen bond of acetylene. Titanium atoms react spontaneously with acetylene to yield a complex. Titanium atoms react with ethylene to form either a three-membered ring or a dicarbene and higher complexes.
Engineering Silver Nanoparticles: Towards a Tunable Antimicrobial
(2014-03-11) Puppala, Hema Lakshmi; Colvin, Vicki L.; Billups, W. Edward; Bennett, George N.
Overwhelming production of commercially available products containing silver nanoparticles (AgNPs) underscores the studies determining their fate in the environment. In order to regulate the use, assess the environmental impact and develop eco-responsible silver products, models that can predict AgNP toxicity based on physicochemical properties are vital. With that vision, this thesis developed well-characterized model libraries of uniform AgNPs stabilized with oleate in the range of 2-45 nm diameter with variable surface coating and investigated the dissolution properties that link AgNP structure to antimicrobial activity. High temperature organic synthesis allowed controlled growth of AgNPs (σ<15%) by an Ostwald ripening mechanism in the first few hours, and followed by size dependent growth rates yielding uniform nanocrystals. Characterization of these materials revealed a crystalline nature, bidentate binding mode of oleate and non-oxidized pristine silver surface. Phase transfer of these AgNPs from organics to water was facilitated by encapsulation and ligand exchange methods using amphiphilic polymers and methoxy poly (ethylene glycol) (mPEGSH) respectively. Among these surface coatings, steric stabilization by mPEGSH not only helped retain their optical properties but also reduced the dissolution (<1(w/w)%) of AgNPs. This enhanced the stability in various environmentally relevant high ionic strength media (such as Hoaglands, EPA hard water and OECD medium), thereby increasing the shelf life. In addition, size, surface coating, pH of the medium and grafting density of the polymer mediated the dissolution of AgNPs. For instance, the rate of dissolution was decreased by 40% when the polymer coating possessed a mushroom conformation and increased with reducing core size. Analogous to dissolution, physicochemical properties also influenced the antimicrobial activity which were studied by minimum inhibitory concentration (MIC) and bactericidal efficacy assays. For example, surface passivation with mPEGSH prevented the oxidation of active silver atoms on the surface, and resulted in reduced toxicity against E. coli. Moreover citrate stabilized AgNPs when surface modified with mPEGSH had reduced toxicity, which was correlated with residual Ag+ in AgNP solution. Therefore this study demonstrates that processes in the environment that increase stability of AgNPs could make them more persistent due to low dissolution. Furthermore, the size and surface chemistry effects of AgNPs studied here make the intrinsic antimicrobial property of silver tunable and hence more versatile. This work also served as a material support for research on investigating toxicity of AgNPs to C. elegans, Daphnia Magna, Populus and Arabidopsis. In the future, this data will be used to develop nanomaterial bioavailability & environmental exposure (nanoBEE) models that predict the environmental impact of AgNPs.
Fullerene hydrides and studies toward the syntheses of fulvalenes
(2005) Peera, Asghar A.; Billups, W. Edward
Benkeser reduction was used to synthesize highly hydrogenated fullerenes, C60H36, C60H38, C 60H40, C60H42 and C60H 44. 1H- and 13C-NMR spectra of HPLC purified fractions show that more highly hydrogenated fullerenes exhibit signals that are shifted upfield. The opposite trend was observed in 3He NMR spectra of the corresponding endohedral helium compounds. The trend in the 3He NMR is attributed to the change in the shape of various hydrogenated fullerenes. Hydrogenated single-walled carbon nanotubes (H-SWNTs) were prepared via the dissolved metal reduction method in liquid ammonia and by Anhydrous Hydrazine in methanol. Spectroscopic analysis of the H-SWNTs shows that hydrogen is covalently attached to the tubes. Scanning Tunneling Microscopy (STM) images of the hydrogenated tubes show bright regions around the circumference of the tube that most likely correspond to the region covered by hydrogen. Precursors of two fulvalenes (calicene and triafulvalene) were prepared by multi-step synthetic procedures. The calicene precursor was obtained by base-induced dehydrobromination, while that of triafulvalene was obtained by a metathesis reaction using first generation Grubbs catalyst. The two precursors are attractive candidates for the parent compounds by using solid fluoride as the dehalosilylation inducing reagent in the final step.
Functionalization of Nanocarbons for Composite, Biomedical and Sensor Applications
(2013-07-24) Kuznetsov, Oleksandr; Billups, W. Edward; Hauge, Robert H.; Rau, Carl
New derivatives of carbon nanostructures: nanotubes, nano-onions and nanocrystalline diamonds were obtained through fluorination and subsequent functionalization with sucrose. Chemically modified nanocarbons show high solubility in water, ethanol, DMF and can be used as biomaterials for medical applications. It was demonstrated that sucrose functionalized nanostructures can find applications in nanocomposites due to improved dispersion enabled by polyol functional groups. Additionally, pristine and chemically derivatized carbon nanotubes were studied as nanofillers in epoxy composites. Carbon nanotubes tailored with amino functionalities demonstrated better dispersion and crosslinking with epoxy polymer yielding improved tensile strength and elastic properties of nanocomposites. Reductive functionalization of nanocarbons, also known as Billups reaction, is a powerful method to yield nanomaterials with high degree of surface functionalization. In this method, nanocarbon salts prepared by treatment with lithium or sodium in liquid ammonia react readily with alkyl and aryl halides as well as bromo carboxylic acids. Functionalized materials are soluble in various organic or aqueous solvents. Water soluble nanodiamond derivatives were also synthesized by reductive functionalization of annealed nanodiamonds. Nanodiamond heat pretreatment was necessary to yield surface graphene layers and facilitate electron transfer from reducing agent to the surface of nanoparticles. Other carbon materials such as activated carbon and anthracite coal were also derivatized using reductive functionalization to yield water soluble activated carbon and partially soluble in organic solvents anthracite. It was shown that activated carbon can be effectively functionalized by Billups method. New derivatives of activated carbon can improve water treatment targeting specific impurities and bio active contaminants. It was demonstrated that functionalized carbon nanotubes are suitable for real time radiation measurements. Radiation sensor incorporating derivatized carbon nanotubes is lightweight and reusable. In summary, functionalization of carbon nanomaterials opens new avenues for processing and applications ranging from biomedicine to radiation sensing in space.
Functionalized Nanoparticles for Biomedical Applications
(2013-09-16) Bryant, Erika; Billups, W. Edward; Hauge, Robert H.; Pasquali, Matteo
Functionalization of nanoparticles often control the extent of their usage. With this in mind, I have explored methods of creating highly functionalized exfoliated graphite, by way of the Billups-Birch reduction, that can be used in the advancement of nanotechnology (i.e. biomedicine). The method explored the use of sodium as the source for the solvated electron. The results of this method produced exfoliated graphite the same size as graphene and with solubility similar to the substrates attached to it. It was further shown that functionalized graphite with a terminal carboxyl group allowed further synthesis to occur via an elimination-addition reaction after the acyl group was transformed into an acid chloride. This reaction makes it possible to create exfoliated graphite that contains any compound of interest as long as it has an oxygen or nitrogen group that is able to react with the acid chloride. Thus, these products have the potential to be used in biomedicine as drug delivery agents.
Identity and near identity rates and equilibria for methyl group transfers between arenesulfonate ions
(1984) Hu, Daniel David; Lewis, Edward S.; Billups, W. Edward; Stanbury, David M.
Rates and equilibria were measured for the reaction of methyl arenesulfonates with arenesulfonates in sulfolane. The identity rates for a series of arenesulfonates were measured at a variety of temperatures; a Hammett P was obtained. A Hammett P of ~22.9 was obtained for nonidentity equilibria. Arrhenius plots are inconclusive due to large error limits. The transition state for the identity reaction lies near the area predicted by Albery and Kreevoy. Using the identity rates and measured mixed case equilibrium constants, a test of the Marcus equation with and without the quadratic term was conducted. The test suggests that the Marcus equation is a decent predictive tool for the rate of methyl transfers in solution. The Marcus equation was used to estimate an identity rate for methyltriflate.
Multiple isomers of carbon(60)hydrogen(36): The products of the birch reduction of carbon(60)
(2000) Nossal, Jamie R.; Billups, W. Edward
The product mixture of the lithium Birch reduction of C60 is analyzed. C60H36 is identified as the major product; C60H32, C60H38 and C60H 40 are identified as minor products. The product mixture is separated into four fractions by high pressure liquid chromatography. 3He NMR spectra are obtained for the fractions by reduction of 3He C 60 and the 3He chemical shifts are compared to calculated values. The dihydroanthracene reduction of C60 is shown by high pressure liquid chromatography to produce a single major isomer of C 60H36. A comparison of the 3He NMR spectra determines that the major dihydroanthracene C60H36 isomer has C3 symmetry and that this isomer is also obtained by the Birch reduction of C60. C60H38, C60H 40 and C60H42 are synthesized by the lithium-ethylenediamine reduction of C60H36. 1,2-C70H 2 is synthesized by anhydrous hydrazine reduction of C70.
Radiofrequency-induced Cellular Hyperthermia: Water-soluble Fullerene as a New Cancer Therapeutic Agent
(2014-09-08) Cheney, Matthew Andrade; Wilson, Lon J.; Curley, Steven A.; Billups, W. Edward; Jacot, Jeffrey G.
Due to the susceptibility of cancer to hyperthermia, abundant biomedical research is being conducted for the development of therapies using nanotechnology for noninvasive cancer hyperthermia. In this work, the water-soluble and neutrally-charged C60 fullerene, C60-ser, is presented as a new cancer therapeutic agent for the hyperthermia of liver cancer using radiofrequency (RF) energy. With liver cancer being the second leading cause of death in men and the sixth most in women worldwide, new and improved therapies are needed to combat the limitations associated with current cancer treatments. Using a RF generator operating at 13.56 MHz, aqueous heating of purified C60-ser within the RF field has been observed in a concentration- and aggregation-dependent manner. These findings now lay the foundation for a new cancer hyperthermia therapy using C60 fullerene. Though the exact mechanism of C60-ser heating within the RF field is still uncertain, evidence has shown that the six serinol malonate (ser) groups of C60-ser must be attached to C60 to produce any significant heating. C60 is known to play numerous roles in the biomedical field, including drug delivery, active cancer cell targeting, bone therapy, gene therapy, X-ray contrast enhancement, and now, through the present work, as a potential new cancer therapy by RF-induced hyperthermia. By attaching a fluorescent tag (PF) to C60-ser to form C60-serPF, passive and active internalization into Hep3B and Huh7 liver cancer cells has been observed, with evidence of internalization within the cytoplasm and, more surprisingly, the nucleus. Very few nanomaterials have been definitively proven to internalize within the nucleus of cells, raising the potential for both C60-ser and C60-serPF to be used for other biomedical purposes and not just solely for RF-induced hyperthermia effects on cellular DNA. In vivo biodistribution studies of C60-serPF also has showed its presence in all major organs, including the brain. Since C60-ser was shown to inhibit the internalization of C60-serPF in vitro, uptake by liver cancer cells of both nanomaterials proceed by similar pathways. Therefore, the ability of C60-serPF to traverse the blood brain barrier of mice suggests an array of opportunities for brain-related treatments and therapies using both C60-serPF and C60-ser. Taken together, the materials provide simultaneous diagnostic and therapeutic capabilities, making them a new class of theranostic agent. In vitro studies of C60-ser have shown that it is non-toxic at up to 1.0 mg/mL to liver cancer cells (Hep3B, SNU449, and HepG2), that it modulates cellular metabolic activity, that it negligibly influences the cell cycle, but that it does not promote radiofrequency-induced hyperthermia of individual liver cancer cells. However, when injected intratumorally in mice, C60-ser enhanced the RF heating of liver tumors by 89% and 26% when compared to PBS and water controls alone, respectively. This observed increase in heating led to significant necrosis for the C60-ser treated groups, while necrosis for the control groups was nonexistent. This work has shown in vivo efficacy of an RF/C60-ser combination therapy by hyperthermia for the treatment of liver cancer for the first time. Future directions must involve the incorporation of biological targeting groups conjugated to the C60 moiety to realize the full potential of a noninvasive and targeted approach to cancer cell hyperthermia for liver cancer and other types of cancer, as well.
Re-Engineering the alkanolamine absorption process to economize carbon capture
(2013-09-16) Warudkar, Sumedh; Hirasaki, George J.; Wong, Michael S.; Chapman, Walter G.; Cox, Kenneth R.; Billups, W. Edward
Climate change caused by carbon dioxide (CO2) released from the combustion of fossil fuels threatens to have a devastating impact on human life. Power plants that burn coal and natural gas to produce electricity generate more than half of global CO2 emissions. Separating the CO2 emitted at these large sources of emission, followed by long term storage has been proposed as short to medium term solution to mitigate climate change. Implementation of this strategy called 'Carbon Capture and Storage' would allow the continued use of fossil fuels while simultaneously reduce our CO2 emissions. Technologies such as the alkanolamine absorption process, used to separate CO2 from gas mixtures already exist. However, it is presently infeasible to use them for Carbon Capture and Storage due to their relatively large energy consumption. It is estimated that even with the use of state-of-the-art technology, the cost of electricity will increase by around 90%. The research presented in this dissertation is focused on developing novel strategies to limit the increase in the cost of electricity due to implementation of Carbon Capture and Storage. In order to achieve this objective, a process simulation software; ProMax® has been used to optimize the alkanolamine absorption process to suit Carbon Capture application. A wide range of process operating conditions has been analyzed for their effects on energy consumption. Included in this study are process conditions under which waste heat can be utilized for providing energy instead. Based on this analysis, some of the most energy efficient process configurations have been identified for an economic evaluation of their capital costs. This research has also led to the invention of novel absorbent blends which involve the replacement of water used in CO2 absorbents with alcohols. It has been shown that the use of these absorbents can significantly reduce energy consumption and thereby limit the increase in cost of electricity.
Studies on nitrile rubber degradation in zinc bromide completion fluid and its prevention by surface fluorination
(2002) Vega-Cantu, Yadira Itzel; Billups, W. Edward
Poly(acrylonitrile-co-butadiene) or nitrile-butadiene rubber (NBR) is frequently used as an O-ring material in the oil extraction industry due to its excellent chemical properties and resistance to oil. However, degradation of NBR gaskets is known to occur during the well completion and oil extraction process where packers are exposed to completion fluids such as ZnBr2 brine. Under these conditions NBR exhibits accelerated chemical degradation resulting in embrittlement and cracking. Samples of NBR, poly(acrylonitrile) (PAN) and poly(butadiene) (PB) have been exposed to ZnBr2 based completion fluid, and analyzed by ATR and diffuse reflectance IR. Analysis shows the ZnBr2 based completion fluid promotes hydrolysis of the nitrile group to form amides and carboxylic groups. Analysis also shows that carbon-carbon double bonds in NBR are unaffected after short exposure to zinc bromide based completion fluid, but are quickly hydrolyzed in acidic bromide mixtures. Although fluoropolymers have excellent chemical resistance, their strength is less than nitrile rubber and replacing the usual gasket materials with fluoroelastomers is expensive. However, a fluoropolymer surface on a nitrile elastomer can provide the needed chemical resistance while retaining their strength. In this study, we have shown that this can be achieved by direct fluorination, a rather easy and inexpensive process. Samples of NBR O-rings have been fluorinated by exposure to F2 and F2/HF mixtures at various temperatures. Fluorination with F 2 produces the desired fluoropolymer layer; however, fluorination by F2/HF mixtures gave a smoother fluorinated layer at lower temperatures and shorter times. Fluorinated samples were exposed to ZnBr2 drilling fluid and solvents. Elemental analysis shows that the fluorinated layer eliminates ZnBr2 diffusion into the NBR polymeric matrix. It was also found that surface fluorination significantly retards the loss of mechanical properties such as elasticity, tensile strength, toughness and compression set of nitrile rubber when exposed to zinc bromide fluid. This surface fluorination can be applied to extend the useful life of O-rings and packers in the field during oil extraction. The extended life can save millions of dollars by limiting the downtime of the well.
Studies on the synthesis and properties of cyclopropenes
(1990) Lee, Gon-Ann; Billups, W. Edward
Tetra-n-butylammonium fluoride supported on glass helices was used to generate cyclopropenes in the gas phase from $\beta$-halocyclopropylsilanes using the vacuum gas-solid reaction (VGSR) technique. Bicyclo (4.1.0) hept-1,7-ene (1), bicyclo (4.1.0) hept-1,6-ene (2), and bicyclo (5.1.0) oct-1,8-ene (3) were prepared from the appropriate $\beta$-chlorocyclopropylsilanes.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Compounds 1 and 2 underwent ene reactions to give the same dimer 4. Compound 4 isomerized to 5 via cyclopropene-vinyl carbene rearrangements. Dimerization of 4 led to the cycloaddition adducts 6 and 7 (tetramers of 1).(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Treatment of either 4 or 5 with oxygen formed 2-(bicyclo (4.1.0) hept-1-yl)-1-cyclohexenecarboxaldehyde (8) and 1-(bicyclo (4.1.0) hept-1-yl)-cyclohepten-3-one (9).(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Hydrogenation 4 and 5 below $-$20$\sp\circ$C yielded products identified provisionally as 10 and 11, respectively. Both 10 and 11 rearranged to meso-1-(bicyclo (4.1.0) hept-1-yl)bicyclo (4.1.0) heptane (12).(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Cyclopropene 3 also reacted via an ene reaction to give both dimer and trimer. Tricyclo (5.5.0.0$\sp{1,6}$) decane (13) was prepared by reduction of the butadiene Diels-Alder adduct of 3. Hydrogenation of 3 gave cis-bicyclo (5.1.0) octane and 1-methylcycloheptane.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)
Synthesis and chemistry of strained ring compounds
(2002) Litosh, Vladislav Alexander; Billups, W. Edward
The gas phase elimination of trimethylsilyl fluoride from beta-halocyclopropylsilanes using solid n-Bu4N+F or CsF adsorbed on glass helices offers a superior route to highly strained alkenes. This approach has been used to synthesize 1-chloro-3-methylenecyclopropene, 1,4-dichlorospiropentadiene, 1,4-dichlorospiropentene, and oxaspiropentene from the appropriate precursors. In each instance the product could be isolated and characterized by low temperature nuclear magnetic resonance spectroscopy. Geometries were defined computationally. The corresponding Diels-Alder adducts of these species with cyclopentadiene or 1,3-butadiene were also obtained and characterized.* Thermolysis of spiro[2.4]hepta-1,4,6-triene at 60°C yields bicyclo[3.2.0]hepta-1,3,5-triene (Ea = 24.7 kcal/mole) which dimerizes in two different fashions forming cyclobutanes. 1,2-Dimethylspiro[2.4]hepta-1,4,6-triene and 1-propylspiro[2.4]hepta-1,4,6-triene also rearrange at 60°C, but at a faster rate, to yield cyclobutane dimers of the corresponding bicyclo[3.2.0]hepta-1,3,5-trienes.* The reactions of benzocyclopropene and cyclopropa[b]naphthalene with metal carbenes were investigated. The cycloproparenes react with Cl2 (Cy3P)2Ru=CH2 to form unstable 3-ruthenabenzocyclopentenes which decompose to give o-xylylenes. o-Xylylenes produced in this way can be trapped as Diels-Alder adducts by dimethyl acetylenedicarboxylate. In contrast, Cp2Ti=CH2 forms moderately stable 2- and 3-titanabenzocyclopentene complexes.* *Please refer to dissertation for diagrams.
Synthesis and reactions of cycloproparenes
(1995) McCord, Dianne Jeannette; Billups, W. Edward
Triscycloproparenes 1 and 2 were synthesized by treating the Diels-Alder adducts of 1-bromo-2-chlorocyclopropene and either hexaradialene (3) or hericene (4) with potassium t-butoxide. New cycloproparenes 5 and 6 were also isolated using this approach.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) The thermolysis of cyclopropa (b) naphthalene with C$\sb{60}$ was investigated and was found to yield a new Fullerene adduct. The biradical addition was also performed with $\sp3$He labeled Fullerene, and the product (7) was studied by $\sp3$He NMR.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Silver (I) catalyzed reactions of several cycloproparenes were also investigated. In the absence of nucleophilic protic solvents or other reactants, benzocyclopropene (and its derivatives) could be dimerized to yield linearly fused six-membered rings as illustrated by the reaction of cycloproparene 8. Further aromatization of the dimers could be achieved (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) using DDQ in benzene. This technique was also employed with biscycloproparenes such as 11 and the new triscycloproparenes to obtain ladder polymers and more intricate nonrandomly cross-linked polymers.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)
Synthesis of Carbon Nanomaterials and Their Applications in the Oilfield
(2013-09-16) Lu, Wei; Tour, James M.; Billups, W. Edward; Wong, Michael S.
This dissertation explores the potential applications of nanotechnology in the oilfield including poly(vinyl alcohol) stabilized carbon black nanoparticles for oil exploration and temperature-responsive carbon black nanoparticles for enhanced oil recovery. Also, it describes the rational design of graphene nanoribbons via intercalating reactive metals into multi-walled carbon nanotubes followed by addition of vinyl monomers or haloalkanes. Efficient production and modification of these aforementioned nanomaterials will make them more attractive for applications in the oilfield and electronics materials. A method is reported for detecting the hydrocarbon in the porous media with stabilized nanoparticles that are capable of efficiently transporting hydrophobic molecules through oil-containing rocks and selectively releasing them when a hydrocarbon is encountered. Nano-sized carbon black was oxidized and then functionalized with poly(vinyl alcohol) via a coupling reaction between the polymer's hydroxyl groups and the carboxylic groups on oxidized carbon black. Breakthrough curves show that poly(vinyl alcohol)-coated oxidized carbon black was stable in synthetic sea brine at room temperature and could carry the 14C-labeled radioactive tracer 2,2ˊ,5,5ˊ-tetrachlorobiphenyl through rocks and then released the tracer upon exposure to hydrocarbon. Due to the temperature-sensitivity of hydrogen bonds, higher molecular weight poly(vinyl alcohol) was used to improve the stability of carbon black nanoparticles in synthetic sea brine at higher temperatures. After sulfation, high molecular weight poly(vinyl alcohol) could stabilized carbon black nanoparticles in American Petroleum Institute standard brine at high temperatures. Those nanoparticles could efficiently transport mass-tagged probe molecules through a variety of oil-field rock types and selectively released the probe molecules into the hydrocarbon-containing rocks. Those proof-of-concept chemical nanoreporters can potentially be used under conditions commonly observed in the reservoir, and aid in the recovery of oil that remains in place. Amphiphilic carbon nanoparticles have been prepared that are capable of reversibly transferring across the water/oil interface in a temperature-controlled manner. Nano-sized carbon black was oxidized and then functionalized with amphiphilic diblock polyethylene-b-poly(ethylene glycol) copolymers that were water-soluble at low-to-moderate temperatures but oil-soluble at higher temperatures. The correlation between the phase transfer temperature and the melting temperature of the hydrophobic block of the copolymers and the weight percent of hydrophilic block were investigated. The amphiphilic nanoparticles were used to stabilize oil droplets for demonstrating potential applications in reducing the water/oil interfacial tension, a key parameter in optimizing crude oil extraction from downhole reservoirs. Graphene nanoribbons free of oxidized surfaces can be prepared in large batches and 100% yield by splitting multi-walled carbon nanotubes with potassium vapor. If desired, exfoliation is attainable in a subsequent step using chlorosulfonic acid. The low-defect density of these GNRs is indicated by their electrical conductivity, comparable to that of graphene derived from mechanically exfoliated graphite. Additionally, cost-effective and potentially industrially scalable, in situ functionalization procedures for preparation of soluble graphene nanoribbons from commercially carbon nanotubes are presented. To make alkane-functionalized graphene nanoribbons, multi-walled carbon nanotubes were intercalated by sodium/potassium alloy under liquid-phase conditions, followed by addition of haloalkanes, while polymer-functionalized graphene nanoribbons were prepared via polymerizing vinyl monomers using potassium-intercalated graphene nanoribbons. The correlation between the splitting of MWCNTs, the intrinsic properties of the intercalants and the degree of graphitization of the starting MWCNTs has also been demonstrated. Those functionalized graphene nanoribbons could have applications in conductive composites, transparent electrodes, transparent heat circuits, and supercapcitors.
Synthesis of new cycloproparenes
(1997) Wagner, Robert; Billups, W. Edward
The (2.2) paracyclophane-annelated cycloproparenes 1 and 2 were prepared by treating the Diels-Alder adducts of 1-bromo-chlorocyclopropene and either 1-vinyl (2.2) paracyclophane-1-ene (3) or 1,2-dimethylene (2.2) paracyclophane (4) with potassium t-butoxide in THF. Using the same approach the new cycloproparenes 5 and 6 were obtained from the (2.2) paracyclophanetetraenes 7 and 8.* The silver-ion catalyzed polymerization of the dicycloproparenes 9 and 10 was also studied. This method has shown to be an alternative to the repetitive Diels-Alder reaction in the synthesis of ladder polymers. The ladder polymers 11 and 12 were obtained and characterized by IR, solid-state $\sp{13}$C-NMR and thermogravimetric analysis (TGA).* ftn*Please refer to the dissertation for diagrams.
Synthesis, Characterization, and Biological uses of Carbon Nanoparticles
(2013-07-24) Marcano Quevedo, Daniela; Tour, James M.; Billups, W. Edward; Mikos, Antonios G.
Many diseases have been associated with oxidative stress (OS) which is caused when the production of reactive oxygen species (ROS), such as superoxide (O2•-) and hydroxyl radical (•OH), overcome the scavenging efficiency of living organisms. It is known that ROS production is worsened during traumas related to ischemic events and subsequent reperfusion in which the treatment with fast and effective antioxidants is critical to prevent cell and tissue damage. PEG-HCCs are carbon nanoparticles that showed O2•- and •OH scavenging properties according to electron paramagnetic resonance (EPR) experiments and peroxyl scavenging properties based on oxygen radical absorbance capacity (ORAC) assays. The O2•- quenching capability was also examined in vivo using a mild traumatic brain injury (mTBI) model complicated with hypotension. As result of the PEG-HCCs treatment, the cerebral blood flow (CBF) was restored while normalizing O2•- and nitric oxide (NO•) levels, primarily in the cerebral vasculature
The synthesis and structure of cyclopropenes and cycloproparenes
(1991) Haley, Michael Mark; Billups, W. Edward
Tetra-n-butylammonium fluoride supported on glass helices was used to generate cyclopropenes in the gas phase from $\beta$-halocyclopropylsilanes using the vacuum gas-solid reaction (VGSR) technique. The following cyclopropenes were the target molecules, most of which were prepared successfully and in very good (55-85%) yields. The appropriate precursors were prepared by addition of a halo- or dihalocarbene to an alkenyltrimethylsilane. 1H,5H-Dicycloprop(b,h) anthracene (53) and 1H,4H-dicyclopropa(b,g) phenanthrene (54) were synthesized in 38% and 84% yield, respectively, by dehydrohalogenation with potassium t-butoxide in tetrahydrofuran at $-$20$\sp\circ$C. A key step in the syntheses was the Diels-Alder reaction of two equivalents of 1-bromo-2-chlorocyclopropene with the reactive 1,2,4,5- and 1,2,3,4-tetramethylenecyclohexanes.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) The corresponding dihydro derivatives 64 and 71 were prepared in 31% and 77% yield, respectively. The interesting cyclopropa(b) naphthalene derivative 69 was isolated in 57% yield. The starting compound for 69 was the major product from the reaction of 1-bromo-2-chlorocyclopropene with 1,2,3,4-tetramethylenecyclohexane.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) X-ray structural determinations were performed on cyclopropenes 48 and 49 and on cycloproparenes 24 and 40, in collaboration with Dr. Roland Boese at der Universitat Essen in Essen, Germany. The photoelectron spectrum of 49 was also obtained in collaboration with Prof. Rolf Gleiter at der Universitat Heidelberg in Heidelberg, Germany. These studies showed 49 to exhibit unusual bonding features.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)
Toward Fullerene Immunotherapy with Water-Soluble Paclitaxel-Fullerene Conjugates
(2013-05-13) Berger, Christopher; Wilson, Lon J.; Billups, W. Edward; McNew, James A.; Rosenblum, Michael G.
For the first time, two distinct, well-characterized water-soluble chemotherapeutic-C60 conjugates have been constructed for targeted drug delivery of paclitaxel to cancer cells. In vitro work was carried out in two stages to determine IC50 values of the conjugates. Primarily, work was carried out on A375m melanoma, T-24 bladder carcinoma, and Hep 3B hepatocellular carcinoma cell lines. In these studies, it was revealed that although the first compound, a paclitaxel-2’-succinate-C60 derivative, experienced a dramatic loss of cytotoxicity in comparison to paclitaxel, the second derivative, utilizing a poly(ethylene glycol) linker, demonstrated over 10× better cytotoxicity than paclitaxel itself. Additional in vitro studies were carried out for the purpose of creating a chemotherapeutic-fullerene-monoclonal antibody immunoconjugate for targeted drug delivery. Building on our previous work, supermolecular forces, instead of covalent chemical bonding were used to associate antibodies with the paclitaxel-2’-succinate-C60 derivative to construct an immunoconjugate. While cytotoxicity was measurable, no discernible advantage was seen by the targeted C60-(ZME-018) immunoconjugate over a MuIgG control, thus leaving room for further refinement of the approach for targeted cancer therapy. In vivo work, using the potent paclitaxel-poly(ethylene glycol)-C60 derivative in a murine model, demonstrated success by producing a similar capacity for tumor-reduction compared to the FDA-approved drug Abraxane®, without the associated weight-loss in animals seen for Abraxane. A major contribution of this work is the progress made toward development of Fullerene Immunotherapy (FIT) and the potential translation of FIT into the clinic. Having demonstrated the potent, improved cytotoxicity of a paclitaxel-C60 conjugate, the next step in the development of FIT is the successful construction of a therapeutic fullerene-antibody immunoconjugate. The results documented in this work have now shifted the onus of FIT from a theoretical concept to a realistic goal awaiting final developmental refinement.

Browsing by Author "Billups, W. Edward"

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