Chemistry Commons^™

Unbinding Of Testosterone From The Androgen Receptor And Two Bf-3 Site Mutants, Muniruzzaman Chowdhury

Theses and Dissertations

The androgen receptor (AR) can be activated by molecules binding in the steroid binding pocket. It can also be regulated allosterically by cofactors binding to the AF-2 surface site as well as by exogenous small molecules binding to the BF-3 surface site. Recent data indicated that mutations in the BF-3 site changed the amount of the endogenous steroid needed to activate the receptor, indicating that mutations of BF-3 can cause an allosteric effect. Molecular dynamics and steered molecular dynamics simulations were used to study the allosteric effect of the mutations on AR structure and the unbinding pathways of testosterone (TES) …

Nonwovens Of Ceramic Decorated Cellulose Based Fine Fibers For Leaded Water Purification, Alejandro J. Castillo

Theses and Dissertations

Fine fibers of cellulose acetate were Forcespun and used to make nonwoven mats of cellulose. Nonwovens were activated using a solution combustion synthesis which deposited iron nitride onto fibers. Cellulose and cellulose composite mats were tested as adsorbents for lead ion in water. Cellulose showed slightly higher adsorption capacities (mg/g) up to 1300 mg/g lead loading. Adsorption data were further analyzed using several isotherms, of which the Dubinin-Raduskevich gave the best fits.

Flexible Dye-Sensitized Solar Cells: A Study Of Photoanode And Counter Electrode Materials, Brishty Deb Choudhury

Theses and Dissertations

Compare to flat devices based on rigid substrates, fiber-shaped dye sensitized solar cells hold advantages of smaller size, light weight, facile fabrication, flexibility, and low cost, thus a promising direction for applications such as wearable electronic devices. Due to their unique photovoltaic properties, nanostructured morphologies of TiO2 on flexible substrate have been studied extensively in the recent years for applications in dye sensitized solar cells (DSSCs). Micro-structured electrode materials with high surface area can facilitate rapid charge transport and thus improve the light-to-current conversion efficiency. In the first part of this work the nano-tree morphology of the TiO2 photoanode material …

Li+ Co-Doping Induced Phase Transition As An Efficient Strategy To Enhance Upconversion Of La2zr2o7:Er,Yb Nanoparticles, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Partha Sarathi Ghosh, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The structural phase transition of materials is one of the most active research areas of solid state and materials chemistry in which atomic rearrangements tune fundamental pysochemical properties during the transition. In most cases, such transition requires high temperature, high pressure, or chemical doping. However, phase transition of complex metal oxides such as La2Zr2O7 has not been studied to enhance the upconversion (UC) and downconversion luminescence of their rare-earth doped nanoparticles (NPs) to meet the demand of their broad applications in solar cells, bioimaging, water purification, etc. In this work, we have successfully co-doped Li+ into La2Zr2O7:Er,Yb NPs to …

The Rotational Spectrum Of 1,1-Diiodoethane, Michael Joseph Carrillo

Theses and Dissertations

The first chapter of this thesis introduces the basic theory of rotational spectroscopy. This includes the theory of a rigid rotor, centrifugal distortion, and hyperfine effects. The theory behind diatomic systems is explained first, and then expanded to the asymmetric top system. The second chapter encompasses a brief overview on the development of microwave spectroscopy and discusses the instruments that were utilized during this study, namely the cavity-based and chirped-pulse Fourier transform microwave spectrometers. Chapter three describes the quantum chemical calculation methods and basis sets that were applied throughout this study. Chapter four discusses the progress of data analysis of …

Synthesis And Fabrication Of Self-Sustainable Triboelectric Energy Case For Powering Smart Electronic Devices, Abu Masa Abdullah, Alejandro Flores, Aminur Rashid Chowdhury, Jianzhi Li, Yuanbing Mao, M. Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In recent times, Triboelectric Nanogenerators (TENG) have attained the focus of the scientific community due to its potential as a medium to harvest mechanical energy from the ambient environment. Human motion has been attributed as a source of mechanical energy to drive electronic devices and sensors through TENG. Based on the principles of single electrode TENG, we have developed a Triboelectricity based Stepping and Tapping Energy Case (TESTEC) which magnifies the prospect to power touch electronic devices by utilizing finger tapping and stepping motion. This novel case was constructed with two single electrode TENG operating through the triboelectric mechanism between …

Surface Structure And Phase Composition Of Tio2 P25 Particles After Thermal Treatments And Hf Etching, M. Jasim Uddin, Federico Cesano, Aminur Rashid Chowdhury, Tarek Trad, Sara Cravanzola, Gianmario Martra, Lorenzo Mino, Adriano Zecchina, Domenica Scarano

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The anatase to rutile phase transformation via thermal and chemical (HF etching) routes of TiO2 P25 has been investigated. The treatment parameters and properties of the resulting anatase and rutile nanoparticles are analyzed and discussed. Since the nature of TiO2 surfaces plays a significant role in determining the physical and chemical properties of the TiO2 nanoparticles, it is important to investigate the surface properties, including the morphology, the main exposed faces, the defectiveness, to be correlated with their peculiar properties, and then reactivity. Herein, we report an infrared spectroscopy investigation, employing the adsorption of CO probe molecule at low temperature, …

The Role Of Α, Γ, And Metastable Polymorphs On Electrospun Polyamide 6/Functionalized Graphene Oxide, Javier Macossay-Torres, Yazmin I. Avila-Vega, Faheem A. Sheikh, Travis Cantu, Francisco E. Longoria-Rodriguez, Edgar H. Ramirez-Soria, Rigoberto C. Advincula, Jose Bonilla-Cruz

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The present paper describes the addition of nitroxide-functionalized graphene oxide (GOFT) into polyamide 6 (PA6) micro- and nanofibers, which were obtained through electrospinning. SEM micrographs demonstrated the presence of fibers. Tensile testing presented an unexpected and non-obvious behavior, in which the Young’s modulus, tensile strength, and elongation simultaneously and remarkably increased compared to the pristine polymer nanofibers. GOFT induces the hydrogen bonding between the NH group from PA6 with the functional groups, thus promoting higher crystallinity of the polymer matrix. Nonetheless, deconvoluted DSC curves revealed the presence of two quasi-steady polymorphous (b and d phases) contributing to 46% of the …

Effect Of Hydrothermal Temperature Treatment On The Variance Of Fluorescence In Ca2sio4:Tb3Þ, Rajaboopathi Mani, Santosh K. Gupta

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Investigations of structural defects and their associated impact on the optical properties of optical materials are essential expediencies because different methods are involved in the preparation of those materials for display applications. Lanthanide ion doping is a simple structural probing strategy that facilitates the challenges of identifying the structural defects. Pure and terbium (Tb3+) doped Ca2SiO4 (C2S) particles were prepared using Pechini (C2SP) and hydrothermal methods (C2SH). From SEM images, it is observed that the Tb3+ doped C2SP particles were highly agglomerated, more than the C2SH particles. The TEM study confirmed that the particle size decreased for C2SH prepared at …

Elucidating The Binding Pockect Of The Gpr119 Receptor, A Type 2 Diabetes Target, Matthew Dy Rosales

Theses and Dissertations

An in-house homology model of the GPR119 receptor was used to identify residues which may affect ligand binding and ligand-dependent activity through computational and experimental studies. In a docking study comparing an agonist and its inverse agonist structural analog, Leu5.43169, L6.52242 and Ser1.324 appear to be involved in ligand binding. These residues were mutated experimentally to test the predictions of the homology model. The in vitro studies indicate that Leu5.43169 and Ser1.324 mutations cause ten-fold and six-fold decreases in ligand-induced cAMP formation, indicating their importance in ligand-induced activation. Leu6.52242 mutations show minimal effect in cAMP production, indicating a lesser involvement …

Exploring Pyrochlore Host For Upconversion And Downconversion Luminescence Materials, Mitzy A. Penilla Garcia

Theses and Dissertations

Pyrochlore has been the focal point of research in materials science community in the area of nuclear waste host, thermal barrier coatings, solid oxide fuel cell, catalyst, magnetism, luminescence etc. Such application arises due to their unique properties such as wide band gap, high radiation stability, low thermal conductivity, high dialectic constant. The fact it also has high structural ability, low phono energy and ability to accommodate dopant ion at both A- site and B-site; they are considered excellent host for inorganic phosphors. Here research work is directed towards synthesizing optical materials having high quantum efficiency for down-conversion (DC) and …

The Photon Absorber And Interconnecting Layers In Multijunction Organic Solar Cell, Brishty Deb Chowdhury, Bernabe Ibarra, Federico Cesano, Yuanbing Mao, Muhammad N. Huda, Aminur Rashid Chowdhury, Carolina Olivares, M. Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Organic photovoltaic devices have long been considered as an important alternative for coal-based energy technologies due to their low-cost, lightweight and flexible nature. However, the power conversion efficiencies of such cells are limited by thermalization and transmission losses, which can be overcome by stacking multiple cells in a tandem configuration. This approach allows utilization of the wider spectrum of solar light, helping in attaining the theoretical limits for single cell efficiency (~30%). However, the performance of such tandem organic solar cells depends largely on several factors, including the proper design of absorber, sub-cells and interconnecting layer materials. In this review, …

Versatile Bismuth Salts-Induced Reactions From Our Laboratory: A Perspective, Debasish Bandyopadhyay, Bimal Krishna Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Bismuth salts-mediated reactions are developed for the synthesis of diverse organic molecules of medicinal significance. Reactions conducted with bismuth salts are environmentally friendly and these may proceed due to the release of acids in the media. Bismuth salt may also act as a Lewis acid in these reactions. Versatile organic molecules in chiral and achiral forms are synthesized using bismuth salts-induced reactions at our research laboratory.

Structure–Activity Relationship Of Rgd-Containing Cyclic Octapeptide And Αvβ3 Integrin Allows For Rapid Identification Of A New Peptide Antagonist, Aaron Silva, Wenwu Xiao, Yan Wang, Wei Wang, Heng Wei Chang, James B. Ames, Kit S. Lam, Yonghong Zhang

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The αvβ3 integrin, a receptor for many extracellular matrix proteins with RGD-sequence motif, is involved in multiple physiological processes and highly expressed in tumor cells, therefore making it a target for cancer therapy and tumor imaging. Several RGD-containing cyclic octapeptide (named LXW analogs) were screened as αvβ3 antagonists with dramatically different binding affinity, and their structure–activity relationship (SAR) remains elusive. We performed systematic SAR studies and optimized LXW analogs to improve antagonistic potency. The NMR structure of LXW64 was determined and docked to the integrin. Structural comparison and docking studies suggested that the hydrophobicity and aromaticity of the X7 amino …

Glutaminyl-Trna Synthetase From Pseudomonas Aeruginosa: Characterization, Structure, And Development As A Screening Platform, Yaritza Escamilla, Casey A. Hughes, Jan Abendroth, David M. Dranow, Samantha Balboa, Frank B. Dean, James M. Bullard

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Pseudomonas aeruginosa has a high potential for developing resistance to multiple antibiotics. The gene (glnS) encoding glutaminyl-tRNA synthetase (GlnRS) from P. aeruginosa was cloned and the resulting protein characterized. GlnRS was kinetically evaluated and the KM and kcatobs , governing interactions with tRNA, were 1.0 μM and 0.15 s-1 , respectively. The crystal structure of the α2 form of P. aeruginosa GlnRS was solved to 1.9 Å resolution. The amino acid sequence and structure of P. aeruginosa GlnRS were analyzed and compared to that of GlnRS from Escherichia coli. Amino acids that interact with ATP, glutamine, and tRNA are well …

Effects Of Molten-Salt Processing Parameters On The Structural And Optical Properties Of Preformed La2zr2o7:Eu3+ Nanoparticles, Mitzy A. Penilla Garcia, Santosh K. Gupta, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Molten-salt method has been used to synthesize various functional materials, but it has not been employed to adjust the structure, particle size, and properties of preformed particles. To fill the knowledge gap, in this study, we use a molten-salt medium to reprocess preformed La2Zr2O7:5%Eu3+ nanoparticles which were already formed by a molten-salt synthesis (MSS) method. The molten-salt processing is conducted under various conditions in terms of processing time, temperature, and medium. Specifically, within the studied molten-salt processing time (0 h–24 h) at 800°C, 3 h was found to offer the best optical output. In terms of the investigated molten-salt processing …

Td-Dft Spin-Adiabats With Analytic Nonadiabatic Derivative Couplings, Nicole Bellonzi, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

We present an algorithm for efficient calculation of analytic nonadiabatic derivative couplings between spin-adiabatic, time-dependent density functional theory states within the Tamm-Dancoff approximation. Our derivation is based on the direct differentiation of the Kohn-Sham pseudowavefunction using the framework of Ou et al. Our implementation is limited to the case of a system with an even number of electrons in a closed shell ground state, and we validate our algorithm against finite difference at an S₁/T₂ crossing of benzaldehyde. Through the introduction of a magnetic field spin-coupling operator, we break time-reversal symmetry to generate complex valued nonadiabatic derivative …

Electrospinning Piezoelectric Fibers For Biocompatible Devices, Bahareh Azimi, Mario Milazzo, Andrea Lazzeri, Stefano Berrettini, M. Jasim Uddin, Zhao Qin, Markus J. Buehler, Serena Danti

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and …

On Comparison Of Luminescence Properties Of La2zr2o7 And La2hf2o7 Nanoparticles, Santosh K. Gupta, Maya Abdou, Partha Sarathi Ghosh, Jose P. Zuniga, Ezhilarasan Manoharan, Hyeongjun Kim, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Unveiling the underlying mechanisms of properties of functional materials, including the luminescence differences among similar pyrochlores A2B2O7, opens new gateways to select proper hosts for various optoelectronic applications by scientists and engineers. For example, although La2Zr2O7 (LZO) and La2Hf2O7 (LHO) pyrochlores have similar chemical compositional and crystallographic structural features, they demonstrate different luminescence properties both before and after doped with Eu3+ ions. Based on our earlier work, LHO‐based nanophosphors display higher photo‐ and radioluminescence intensity, higher quantum efficiency, and longer excited state lifetime compared to LZO‐based nanophosphors. Moreover, under electronic O2−→Zr4+/Hf4+ transition excitation at 306 nm, undoped LHO nanoparticles (NPs) …

Td-Dft Spin-Adiabats With Analytic Nonadiabatic Derivative Couplings, Nicole Bellonzi, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Wepresent an algorithm for efficient calculation of analytic nonadiabatic derivative couplings between spin-adiabatic, time-dependent density functional theory states within the Tamm-Dancoff approximation. Our derivation is based on the direct differentiation of the Kohn-Sham pseudowavefunction using the framework of Ou et al. Our implementation is limited to the case of a system with an even number of electrons in a closed shell ground state, and we validate our algorithm against finite difference at an S1/T2 crossing of benzaldehyde. Through the introduction of a magnetic field spin-coupling operator, we break time-reversal symmetry to generate complex valued nonadiabatic derivative couplings. Although the nonadiabatic …

Lanthanide-Doped Lanthanum Hafnate Nanoparticles As Multicolor Phosphors For Warm White Lighting And Scintillators, Santosh K. Gupta, Jose P. Zuniga, Maya Abdou, Melonie P. Thomas, Manisha De Alwis Goonatilleke, Beth S. Guiton, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Designing luminescent materials especially nanomaterials with multifunctional applications is highly challenging and demanding. In this work, we explored pyrochlore La2Hf2O7 nanoparticles (NPs) singly and triply codoped with Eu3+, Tb3+ and Dy3+. Under both ultraviolet and X-ray irradiations, the La2Hf2O7 NPs singly doped with Eu3+, Tb3+ and Dy3+ displayed red, green and yellowish-blue emission, respectively. The concentration quenching study revealed a non-radiative energy transfer in Eu3+ doped La2Hf2O7 NPs, which takes place via dipole-quadrupole mechanism. On the other hand, a dipole-dipole interaction prevails in Tb3+ and Dy3+ doped La2Hf2O7 NPs. Lifetime spectroscopy reveals the stabilization of Eu3+ and Dy3+ ions at …

Tailoring The Viscosity Of Water And Ethylene Glycol Based Tio2 Nanofluids, Abu Musa Abdullah, Aminur Rashid Chowdhury, Yingchen Yang, Horacio Vasquez, Justin Moore, Jason Parsons, Karen Lozano, Jose J. Gutierrez, Karen S. Martirosyan, Mohammed Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Highlights

• Viscosity of TiO2 nanofluid at variable physical parameters has been reviewed.

• Classical and experimental viscosity models of nanofluids have been discussed.

• Preparation techniques of TiO2 nanofluid have been discussed.

• Viscosity of TiO2 nanofluid can increase by 329 times compared to the base fluid.

• Viscosity of TiO2 nanofluid decreases significantly with increasing temperature.

Abstract

Nanofluids have garnered significant attention in the scientific and engineering research communities due to their enhanced heat transfer properties when compared to conventional thermal fluids. Nanofluids comprised of titanium dioxide (TiO2) nanoparticles have a wide range of applications due to their excellent thermophysical properties like thermal …

Lysyl-Trna Synthetase From Pseudomonas Aeruginosa: Characterization And Identification Of Inhibitory Compounds, Samantha Balboa, Yanmei Hu, Frank B. Dean, James M. Bullard

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections and has highly developed systems for acquiring resistance against numerous antibiotics. The gene (lysS) encoding P. aeruginosa lysyl-tRNA synthetase (LysRS) was cloned and overexpressed, and the resulting protein was purified to 98% homogeneity. LysRS was kinetically evaluated, and the Km values for the interaction with lysine, adenosine triphosphate (ATP), and tRNALys were determined to be 45.5, 627, and 3.3 µM, respectively. The kcatobs values were calculated to be 13, 22.8, and 0.35 s−1, resulting in kcatobs/KM values of 0.29, 0.036, and 0.11 s−1µM−1, …

Photocatalytic Degradation Of Simazine Under Visible Light Using Zinc Oxide/Molybdenum Disulfide Heterostructures, Alexandria Castillo

Theses and Dissertations

The photocatalytic degradation of simazine under visible light by using ZnO/MoS2 heterostructures was investigated. Reaction parameters studied to optimize simazine degradation included pH, loading mass of the photocatalyst, and percentage of MoS2 in the heterostructure. pH 2 was the optimal environment for the degradation reaction of all catalysts. A loading mass of 20 mg for each of the ZnO/MoS2 photocatalysts was determined to be the most effective for in the degradation process. The degradation reactions were observed to follow 2nd order kinetics for all photocatalysts at all temperatures. Band gap studies confirmed a lower energy than that of pure ZnO …

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2- butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property …

Biochar Enhances Nitrous Oxide Reduction In Acidic But Not In Near-Neutral Ph Soil, Engil Isadora Pujol Pereira, Jerome Lechot, Rafaela Feola Conz, Abmael Da Silva Cardoso, Johan Six

School of Earth, Environmental, & Marine Sciences Faculty Publications

We quantified nitrous oxide (N2O) fluxes and total denitrification (N2O + N2) in an acidic (Ferralsol) and a near-neutral pH soil (Cambisol) to determine whether biochar’s alkalinization effect could be the mechanism inducing potential reductions in N2O fluxes. In Ferralsol, decreases in N2O emissions and in the N2O to N2O + N2 ratio were observed in both biochar and lime treatments. In Cambisol, neither biochar nor lime decreased N2O emissions, despite significantly increasing soil pH. The abundance and community structure of nosZ gene-bearing microorganisms indicated that gene abundances did not explain biochar effects, but a higher diversity of nosZ gene-bearing …

Samarium-Activated La2hf2o7 Nanoparticles As Multifunctional Phosphors, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Alexander A. Puretzky, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Recent developments in the field of designing novel nanostructures with various functionalities have pushed the scientific world to design and develop high-quality nanomaterials with multifunctional applications. Here, we propose a new kind of doped metal oxide pyrochlore nanostructure for solid-state phosphor, X-ray scintillator, and optical thermometry. The developed samarium-activated La2Hf2O7 (LHOS) nanoparticles (NPs) emit a narrow and stable red emission with lower color temperature and adequate critical distance under near-UV and X-ray excitations. When the LHOS NPs are exposed to an energetic X-ray beam, the Sm3+ ions situated at the symmetric environment get excited along with those located at the …

Nextgen Advises "Trying To Manage", Douglass Steinhauff, Joel Henrique Ellwanger, Monika Lewinska, Edmond Sanganyado, Yongsheng Ji, Buddini Iroshika Karawdeniya, Naike Bochatay, Eric Britt Moore, Aminata Coulibaly, Shaima Ibrahim, Déna Skye Jansen, Joshua I. James, David M. Cole, Anna Lipkin, Beth Mckinnon Adamowicz, Science Management Associates, Shervin Fatehi, Maria Helena Holmstrom, Rosa Li

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Peer mentors can provide crucial support to young scientists by asking questions to facilitate further reflection, assuring mentees that they are not alone, and suggesting potential next steps. We asked our readers to act as peer mentors to “Trying to Manage,” the anonymous student who posed the question above. Follow NextGen Voices on Twitter with hashtag #NextGenSci. Read previous NextGen Voices survey results at https://science.sciencemag.org/collection/nextgen-voices. —Jennifer Sills

Visible And Ultraviolet Upconversion And Near Infrared Downconversion Luminescence From Lanthanide Doped La2zr2o7 Nanoparticles, Santosh K. Gupta, Mitzy A. Penilla Garcia, Jose P. Zuniga, Maya Abdou, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Single materials which have a multitude of photophysical processes by selective doping are in high demand in the community of material science due to their multifunctional applications. Upconversion (UC) and downconversion (DC) luminescence properties of lanthanide doped nanoparticles (NPs) are imperative for their broad application potentials. Here, we describe two series of either doubly or triply doped La2Zr2O7 NPs synthesized by a molten salt method. For the former, La2Zr2O7:Yb,Er NPs display bright red and moderate green UC (VUC) and NIR-B DC (NDC) at around 1550 nm, which are highly desirable for in-vivo bioimaging applications. For the latter, La2Zr2O7:Gd,Yb,Tm NPs demonstrate …

Removal Of As (Iii) And As (V) From Potable Water Using Zno Nanoparticles, Grecia Torreblanca Baez

Theses and Dissertations

Heavy metal and toxic element contamination of the environment has been increasing with increasing industrialization. Arsenic has become an element of particular concern because of its toxicity, which is oxidation state dependent. As(III) is observed to be much more toxic than As(V), as well the removal is more difficult than As(V) in traditional water treatment technology. In the present study, As (III) and As(V) removal was investigated using a zinc oxide nanomaterial that was synthesized using a titration/precipitation technique, and characterized using powder x-ray diffraction. In the present study, the kinetics of adsorption, the adsorption isotherms as well as the …