Physical Sciences and Mathematics Commons^™

Capillary-Tube Package Devices For The Quantitative Performance Evaluation Of Nuclear Magnetic Resonance Spectrometers And Pulse Sequences, Lingyu Chi, Ming Huang, Annalise R. Pfaff, Jie Huang, Rex E. Gerald Ii, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

With the increased sensitivity of modern nuclear magnetic resonance (NMR) spectrometers, the minimum amount needed for chemical-shift referencing of NMR spectra has decreased to a point where a few microliters can be sufficient to observe a reference signal. The reduction in the amount of required reference material is the basis for the NMR Capillary-tube Package (CapPack) platform that utilizes capillary tubes with inner diameters smaller than 150 µm as NMR-tube inserts for external reference standards. It is shown how commercially available electrophoresis capillary tubes with outer diameters of 360 µm are filled with reference liquids or solutions and then permanently …

Application Of A Hygroscopicity Tandem Differential Mobility Analyzer For Characterizing Pm Emissions In Exhaust Plumes From An Aircraft Engine Burning Conventional And Alternative Fuels, Max B. Trueblood, Prem Lobo, Donald E. Hagen, Steven C. Achterberg, Wenyan Liu, Philip D. Whitefield

Chemistry Faculty Research & Creative Works

In the last several decades, significant efforts have been directed toward better understanding the gaseous and particulate matter (PM) emissions from aircraft gas turbine engines. However, limited information is available on the hygroscopic properties of aircraft engine PM emissions which play an important role in the water absorption, airborne lifetime, obscuring effect, and detrimental health effects of these particles. This paper reports the description and detailed labbased performance evaluation of a robust hygroscopicity tandem differential mobility analyzer (HTDMA) in terms of hygroscopic properties such as growth factor (GF) and the hygroscopicity parameter (κ). The HTDMA system was subsequently deployed during …

Bio-Inspired Polydopamine Surface Modification Of Nanodiamonds And Its Reduction Of Silver Nanoparticles, Yun Zeng, Wenyan Liu, Risheng Wang

Chemistry Faculty Research & Creative Works

Surface functionalization of nanodiamonds (NDs) is still challenging due to the diversity of functional groups on the ND surfaces. Here, we demonstrate a simple protocol for the multifunctional surface modification of NDs by using mussel-inspired polydopamine (PDA) coating. In addition, the functional layer of PDA on NDs could serve as a reducing agent to synthesize and stabilize metal nanoparticles. Dopamine (DA) can self-polymerize and spontaneously form PDA layers on ND surfaces if the NDs and dopamine are simply mixed together. The thickness of a PDA layer is controlled by varying the concentration of DA. A typical result shows that a …

Polymer Coated Gold-Ferric Oxide Superparamagnetic Nanoparticles For Theranostic Applications, Muhammad Raisul Abedin, Siddesh Umapathi, Harika Mahendrakar, Tunyaboon Laemthong, Holly Coleman, Denise Muchangi, Santimukul Santra, Manashi Nath, Sutapa Barua

Chemistry Faculty Research & Creative Works

Background: Engineered inorganic nanoparticles (NPs) are essential components in the development of nanotechnologies. For applications in nanomedicine, particles need to be functionalized to ensure a good dispersibility in biological fluids. In many cases however, functionalization is not sufficient: the particles become either coated by a corona of serum proteins or precipitate out of the solvent. We show that by changing the coating of magnetic iron oxide NPs using poly-l-lysine (PLL) polymer the colloidal stability of the dispersion is improved in aqueous solutions including water, phosphate buffered saline (PBS), PBS with 10% fetal bovine serum (FBS) and cell culture medium, and …

The Rotational Spectrum And Potential Energy Surface Of The Ar-Sio Complex, Michael C. Mccarthy, Steve Alexandre Ndengue, Richard Dawes

Chemistry Faculty Research & Creative Works

The rotational spectra of five isotopic species of the Ar-SiO complex have been observed at high-spectral resolution between 8 and 18 GHz using chirped Fourier transform microwave spectroscopy and a discharge nozzle source; follow-up cavity measurements have extended these measurements to as high as 35 GHz. The spectrum of the normal species is dominated by an intense progression of a-type rotational transitions arising from increasing quanta in the Si-O stretch, in which lines up to v = 12 (~14 500 cm^-1) were identified. A structural determination by isotopic substitution and a hyperfine analysis of the Ar-Si¹⁷O …

Novel Porous Polymer Compositions For The Synthesis Of Monolithic Bimodal Microporous/Macroporous Carbon Compositions Useful For Selective Co₂ Sequestration, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed

Chemistry Faculty Research & Creative Works

The present invention discloses novel porous polymeric compositions comprising random copolymers of amides, imides, ureas, and carbamic-anhydrides, useful for the synthesis of monolithic bimodal microporous/macroporous carbon aerogels. It also discloses methods for producing said microporous/macroporous carbon aerogels by the reaction of a polyisocyanate compound and a polycarboxylic acid compound, followed by pyrolytic carbonization, and by reactive etching with CO₂ at elevated temperatures. Also disclosed are methods for using the microporous/macroporous carbon aerogels in the selective capture and sequestration of carbon dioxide.

Solid State Nmr Spectroscopy/Imaging In Situ Measuring Devices And Methods For Calibration And Determining One Or More Quantitative Properties Of A Target Sampleabstract, Lingyu Chi, Ming Huang, R. Gerald Ii, Klaus Woelk

Chemistry Faculty Research & Creative Works

In situ measuring devices, methods of making the same, and methods of using the same are provided herein. The in situ measuring devices can include a capillary tube having a reference material sealed inside the capillary tube, where the capillary tube is positioned inside of a solid state or MAS NMR rotor. A target sample can also be positioned in the interior of the solid state or MAS NMR rotor but is sequestered from the reference material by a capillary tube wall. The in situ measuring devices can be used in solid state MAS NMR spectroscopy to quantify one or …

Solid State Nmr Spectroscopy/Imaging In Situ Measuring Devices And Methods For Calibration And Determining One Or More Quantitative Properties Of A Target Sample, Lingyu Chi, Ming Huang, Rex E. Gerald, Klaus Woelk

Chemistry Faculty Research & Creative Works

In situ measuring devices, methods of making the same, and methods of using the same are provided herein. The in situ measuring devices can include a capillary tube having a reference material sealed inside the capillary tube, where the capillary tube is positioned inside of a solid state or MAS NMR rotor. A target sample can also be positioned in the interior of the solid state or MAS NMR rotor but is sequestered from the reference material by a capillary tube wall. The in situ measuring devices can be used in solid state MAS NMR spectroscopy to quantify one or …

Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin

Mining Engineering Faculty Research & Creative Works

A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional …

Flexible To Rigid Nanoporous Polyurethane-Acrylate (Puac) Type Materials For Structural And Thermal Insulation Applications, Nicholas Leventis, Chariklia Sotiriou-Leventis, Abhishek Bang

Chemistry Faculty Research & Creative Works

Novel urethane-acrylate (UAC) Star monomers and polyurethane-acrylate (PUAC) aerogel polymers derived therefrom are described herein, along with other novel, related monomers and polymers. Also described herein are processes for preparing the UAC Star monomers, the PUAC aerogel polymers, and the other related monomers and polymers. The PUAC and related polymers herein are useful in various applications including in structural and thermal insulation.

Scalable, Hydrophobic And Highly-Stretchable Poly(Isocyanurate-Urethane) Aerogels, Sadeq Malakooti, Saman Rostami, Habel Gitogo Churu, Huiyang Luo, Jenna Clark, Fabiola Casarez, Owen Rettenmaier, Soheil Daryadel, Majid Minary-Jolandan, Chariklia Sotiriou-Leventis, Nicholas Leventis, Hongbing Lu

Chemistry Faculty Research & Creative Works

Scalable, low-density and flexible aerogels offer a unique combination of excellent mechanical properties and scalable manufacturability. Herein, we report the fabrication of a family of low-density, ambient-dried and hydrophobic poly(isocyanurate-urethane) aerogels derived from a triisocyanate precursor. The bulk densities ranged from 0.28 to 0.37 g cm^-3 with porosities above 70% v/v. The aerogels exhibit a highly stretchable behavior with a rapid increase in the Young's modulus with bulk density (slope of log-log plot > 6.0). In addition, the aerogels are very compressible (more than 80% compressive strain) with high shape recovery rate (more than 80% recovery in 30 s). Under …

Salt-Assisted Ultrasonic Disaggregation Of Nanodiamond, Vadym Mochalin, Kostiantyn Turcheniuk, Caleb Trecazzi

Chemistry Faculty Research & Creative Works

Methods for disaggregating nanodiamond clusters, for example, by using ultrasound to break apart nanodiamond aggregates in a sodium chloride aqueous slurry. Compositions, such as aqueous nanodiamond dispersions and dry particulate compositions that may be produced using these methods.

Nmr Studies Of Loaded Microspheres, Ming Huang, Sisi Chen, Rex E. Gerald Ii, Jie Huang, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

Porous-wall hollow glass microspheres (PWHGMs) are a novel form of glass materials that consist of 1-μm-thick porous silica shells, 20-100 μm in diameter, with a hollow cavity in the center. Utilizing the central cavity for material storage and the porous walls for controlled release is a unique combination that renders PWHGMs a superior vehicle for targeted drug delivery. In this study, NMR spectroscopy was used to characterize PWHGMs for the first time. A vacuum-based loading system was developed to load PWHGMs with various compounds followed by a washing procedure that uses solvents immiscible with the target material. Immiscible binary model …

Epoxy Phosphonate Ester As A Coupling Agent For Transition Metal And Metal Oxide Surfaces, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and an epoxy ring, wherein the epoxy group remains intact after the reacting. A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and a functionalized epoxy ring, wherein the functionalized epoxy group remains intact after the reacting. A composite material comprising surface-modified metal oxide nanoparticles dispersed within a polymeric material, wherein the surface modification comprises a compound comprising an ester group and an epoxy ring is also …

Rapid Adsorption Of Proinflammatory Cytokines By Graphene Nanoplatelets And Their Composites For Extracorporeal Detoxification, Yishan Zheng, Nicholas Pescatore, Yury Gogotsi, Boris Dyatkin, Ganesh Ingavle, Vadym Mochalin, Tochukwu Ozulumba, Sergey Mikhalovsky, Susan Sandeman

Chemistry Faculty Research & Creative Works

Sepsis is a complex clinical syndrome that features excessive release of cytokines and other inflammatory mediators that could lead to organ dysfunction. Despite different treatment and management options, sepsis associated high morbidity and mortality rates remain. This has prompted intensive research into alternative therapeutic approaches such as targeted removal of sepsis related molecules using extracorporeal hemoperfusion. In this study, we explore the use of graphene nanoplatelets (GNP) as low-cost alternative hemosorbents for rapid removal of a broad spectrum of proinflammatory cytokine markers. Firstly, the physical characteristics, cytotoxicity, and cytokine marker adsorption profile of GNP were assessed. The results not only …

Harmful Algae, Algal Toxin, Taste And Odor Control And Mitigation In Public Water System, Haiting Zhang

Doctoral Dissertations

“Recent years, harmful algal blooms occurrence has increased quickly in the surface water worldwide, which has become a concern for drinking water plants due to the ability of toxic algae (cyanobacteria) to produce cyanotoxins including microcystins (MCs), mainly MC-LR, cylindrospermopsin (CYN), and taste and odor (T&O) compounds. Various types of chemicals are widely used in drinking water treatment plants as oxidants for treating source water challenged with harmful algal blooms. In this study, the release and degradation of intracellular MC-LR due to oxidation of Microcystis aeruginosa (M. aeruginosa), most common specie of cyanobacteria, was examined kinetically. Effect of …

Electrodeposited Semiconductor Nanostructures & Epitaxial Thin Films For Flexible Electronics, Naveen Kumar Mahenderkar

Doctoral Dissertations

"Single-crystal Si is the bedrock of semiconductor devices due to the high crystalline perfection which minimizes electron-hole recombination, and the dense native silicon oxide which minimizes surface states. To expand the palette of electronic materials beyond planar Si, an inexpensive source of highly ordered material is needed that can serve as an inert substrate for the epitaxial growth of grain boundary-free semiconductors, photonic materials, and superconductors. There is also a need for a simple, inexpensive, and scalable fabrication technique for the growth of semiconductor nanostructures and thin films. This dissertation focuses on the fabrication of semiconducting nanowires (polycrystalline Ge & …

Part I: Design, Synthesis, And Studies Of Novel Age-Inhibitors And Age-Breakers; Part Ii: Novel Synthetic Methods For Organofluorine Compound, Jatin Mehta

Doctoral Dissertations

"Novel small molecule inhibitors and breakers of advanced glycation end-products (AGEs) have been synthesized and their in vitro inhibitory activities have been studied by ¹³C NMR, fluorescence, and UV-visible spectroscopy. We have demonstrated that these AGE-inhibitors and AGE-breakers were found to be more effective in their sequestration of AGE intermediates, such as dehydroascorbate (DHA) than the state-of-the art phenacylthiazolium bromide (PTB)-based AGE-inhibitors and AGE-breakers. Citric acid and other polyphenolic antioxidants have substantial AGE inhibitory effects in the D-glucose/leucine or benzylamine Maillard reaction model systems, and thus they are suitable as dietary additives for ameliorating AGE-induced complications.

Organofluorine compounds have …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

Cappack Devices For The Evaluation Of Parameters And Pulse Performances In Liquid And Solid-State Nmr Spectroscopy, Lingyu Chi

Doctoral Dissertations

"NMR spectroscopy is a powerful analytical tool to obtain explicit information about molecular structures, conformations, dynamics, and functions. To extract the desired information most accurately, NMR reference standards and devices are needed for calibrating the spectrometer hardware, generating reference data for the NMR software, and testing the applicability of pulse sequences. In this dissertation, the CapPack (Capillary-tube Package) platform is introduced which provides well-defined external reference and calibration standards for liquid and solid-state NMR applications. CapPacks consist of one or more permanently sealed capillary tubes that, depending on the intended application, come arranged in different geometries such as side-by-side or …

Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull

Doctoral Dissertations

"Electrochemical deposition methods are presented for the deposition of Co(OH)₂ and Cu metal. Paper I shows the deposition of β-Co(OH)₂ on Ti through electrochemical reduction of [Co(en)₃]³⁺ to [Co(en)₃]²⁺ in 2M NaOH. The catalytic properties of the deposited Co(OH)₂ towards water oxidation is found comparable to Co₃O₄, with the surface of the Co(OH)₂ converting to CoOOH during the reaction. Paper II gives the conditions suitable for epitaxial growth of Co(OH)₂ on Au(100), Au(110), and Au(111) following the same reduction mechanism as described in Paper I. …

Phenolic Resin Aerogels: The Significance Of Inserting An Oxidative Ring-Fusion Aromatization Step At The Early Stages Of Pyrolytic Carbonization, And The Application Of These Materials In Co₂ Storage And Separation, Hojat Majedi Far

Doctoral Dissertations

"Phenolic aerogels, prepared via polycondensation of phenolic monomers and formaldehyde, were converted to carbon aerogels at 800 ⁰C/Ar followed by reactive etching under flowing CO₂. Previously, it was found that a lower-temperature air-oxidation of polybenzoxazine aerogels was necessary in order to obtain highly porous, isomorphic carbon aerogels with high carbonization yields. Using those findings as the point of departure, phenolic aerogels were oxidized at 240 ⁰C/air prior to carbonization. During that air-oxidation step, phenolic aerogels based on phloroglucinol (1,3,5- trihydroxybenzene) undergo fusion of their aromatic rings, yielding 6-membered heteroaromatic pyryliums with pendant phenoxide ions. The resulting carbon aerogels …

Aerogels For Energy Storage Applications: From Shape Memory Materials To Thermites And Explosives, Suraj Donthula

Doctoral Dissertations

"Aerogels are three dimensional highly porous solid objects that provide density reduction compared to dense objects. Those materials can have applications in different classes of energy storage and the two types that are focused in this dissertation are mechanical energy and thermal energy storage. Shape memory materials can store and recover elastic deformation energy when triggered by an external stimulus such as temperature. To incorporate those properties, shape memory polymeric aerogels (SMPA) were synthesized from a rigid isocyanurate containing triisocyanate (N3300 A) and four short oligomeric derivatives of ethylene glycol: H(OCH₂CH₂)_nOH (1 ≤ n …

Evaluation Of The Redesign Of A Stem Gatekeeper Course, General Chemistry I, Incorporating Active-Learning Strategies And Implementation Of A Student-Choice Model, Travis Rae Mcdowell

Doctoral Dissertations

"The first courses freshman university students typically enroll in are the introductory science and math, courses that bridge from and build upon their prior educational experiences. These introductory courses often have large enrollment lectures coupled with supplemental sessions to teach using traditional educational practices, which may operate counter to the attitudes and culture of the students who take them. To address this, the general chemistry faculty through collaboration with a team of educational specialists initiated a redesign of the general chemistry course, which primarily serves first-year undergraduates. The redesign efforts included changes such as reducing lecture time and placing emphasis …