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Articles 1 - 29 of 29
Full-Text Articles in Physical Sciences and Mathematics
Using Clinical Decision Support To Maintain Medication And Problem Lists: A Pilot Study To Yield Higher Patient Safety, Chiang S. Jao, Daniel B. Hier, William L. Galanter
Using Clinical Decision Support To Maintain Medication And Problem Lists: A Pilot Study To Yield Higher Patient Safety, Chiang S. Jao, Daniel B. Hier, William L. Galanter
Chemistry Faculty Research & Creative Works
To Investigate Whether Clinical Decision Support that Automates the Matching of Ordered Drugs to Problems (Clinical Diagnoses) on the Problem List Can Enhance the Maintenance of Both Medication and Problem Lists in the Electronic Medical Record, We Designed a Clinical Decision Support System to Match Ordered Drugs on the Medication List and Ongoing Problems on the Problem List. We Evaluated the Capability and Performance of This Clinical Decision Support System in Medication-Problem Matching using Physician Expert Chart Audits to Match Ordered Drugs to Ongoing Clinical Problems. a Clinical Decision Support System Was Shown to Be Useful in Improving Medication-Problem Matches …
Three-Dimensional Modeling Of The Plasma Arc In Arc Welding, Gu Xu, J. Hu, Hai-Lung Tsai
Three-Dimensional Modeling Of The Plasma Arc In Arc Welding, Gu Xu, J. Hu, Hai-Lung Tsai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as …
Phase Transitions In Lafeaso: Structural, Magnetic, Elastic, And Transport Properties, Heat Capacity And Mössbauer Spectra, Michael A. Mcguire, Andrew D. Christianson, Athena S. Sefat, Brian C. Sales, Mark D. Lumsden, Rongying Jin, Edward Andrew Payzant, David G. Mandrus, Yanbing Luan, Veerle M. Keppens, Vijayalaksmi Varadarajan, Joseph W. Brill, Raphäel P. Hermann, M. T. Sougrati, Fernande Grandjean, Gary J. Long
Phase Transitions In Lafeaso: Structural, Magnetic, Elastic, And Transport Properties, Heat Capacity And Mössbauer Spectra, Michael A. Mcguire, Andrew D. Christianson, Athena S. Sefat, Brian C. Sales, Mark D. Lumsden, Rongying Jin, Edward Andrew Payzant, David G. Mandrus, Yanbing Luan, Veerle M. Keppens, Vijayalaksmi Varadarajan, Joseph W. Brill, Raphäel P. Hermann, M. T. Sougrati, Fernande Grandjean, Gary J. Long
Chemistry Faculty Research & Creative Works
We present results from a detailed experimental investigation of LaFeAsO, the parent material in the series of “FeAs” based oxypnictide superconductors. Upon cooling, this material undergoes a tetragonal-orthorhombic crystallographic phase transition at ~160 K followed closely by an antiferromagnetic ordering near 145 K. Analysis of these phase transitions using temperature dependent powder x-ray and neutron-diffraction measurements is presented. A magnetic moment of ~0.35µB per iron is derived from Mössbauer spectra in the low-temperature phase. Evidence of the structural transition is observed at temperatures well above the transition temperature (up to near 200 K) in the diffraction data as well …
Iron Oxide Deposits Associated With The Ectosymbiotic Bacteria In The Hydrothermal Vent Shrimp Rimicaris Exoculata, Laure Corbari, Marie Anne Cambon-Bonavita, Gary J. Long, Fernande Grandjean, Magali Zbinden, Françoise Gaill, Philippe Compère
Iron Oxide Deposits Associated With The Ectosymbiotic Bacteria In The Hydrothermal Vent Shrimp Rimicaris Exoculata, Laure Corbari, Marie Anne Cambon-Bonavita, Gary J. Long, Fernande Grandjean, Magali Zbinden, Françoise Gaill, Philippe Compère
Chemistry Faculty Research & Creative Works
The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR) hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the …
Photorefractivity In A Polymeric Composite Photosensitized With Nis Nanocrystals, Tyler M. Fears, Charles Anderson, Jeffrey G. Winiarz
Photorefractivity In A Polymeric Composite Photosensitized With Nis Nanocrystals, Tyler M. Fears, Charles Anderson, Jeffrey G. Winiarz
Chemistry Faculty Research & Creative Works
The photorefractive performance of a polymeric composite photosensitized through the inclusion of NiS nanocrystals is described. The nanocrystals were characterized using visible-absorption spectroscopy, energy-dispersive x-ray spectroscopy, and transmission electron microscopy. We further demonstrate the ability to enhance various aspects of the composite's photorefractive performance by performing ligand exchange on the nanocrystals prior to their incorporation into the polymer composite. This procedure resulted in a lowering of the overmodulation voltage from ~70 to ~50 V/µm without affecting the maximum diffraction efficiency of ~40%. An increase in the two-beam-coupling gain coefficient was similarly observed, increasing from 38 to 79 cm−1. The photoconductivities …
Photolithographically Patterned Covalently Bonded Polythiophene Films Using In Tandem Sol-Gel, Surface Initiated Free Radical And Redox Polymerization Methods, Anand Ghanashyam Sedekar, Naveen Chandrasekaran, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Photolithographically Patterned Covalently Bonded Polythiophene Films Using In Tandem Sol-Gel, Surface Initiated Free Radical And Redox Polymerization Methods, Anand Ghanashyam Sedekar, Naveen Chandrasekaran, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Chemistry Faculty Research & Creative Works
A bifunctional monomer, 3,4-bis(vinyloxy)thiophene (BVOT), that can be polymerized both by radical as well as by redox chemistry was utilized in the fabrication of lithographic patterns of conducting polymer films via a sol-gel method. The judicious use of several chemistries yields polythiophene patterns covalently bonded to substrate showing superior adhesion relative to physically bonded counterparts. The films were characterized electrically and mechanically. Surface confinement starts with a bidentate free radical initiator (Si-AIBN) synthesized via condensation reaction between 3-aminopropyltriethoxysilane (APTES) and azobiscyano-valeric acid. Si-AIBN is attached to the surface of glass by hydrolysis of the ethoxy groups and reaction with the …
Preparation Of Macroporous Conductive Carbon Cerogels From Pyrolysis Of Isocyanate-Crosslinked Resorcinol Formaldehyde Aerogels, Sudhir Mulik, Nicholas Leventis, Chariklia Sotiriou-Leventis
Preparation Of Macroporous Conductive Carbon Cerogels From Pyrolysis Of Isocyanate-Crosslinked Resorcinol Formaldehyde Aerogels, Sudhir Mulik, Nicholas Leventis, Chariklia Sotiriou-Leventis
Chemistry Faculty Research & Creative Works
Carbon aerogels combine typical aerogal properties such as high surface area and low density with electrical conductivity. They are prepared by pyrolysis under N2 or Ar at 600-2100 degrees C of resorcinol formaldehyde (RF) aerogels, which in turn are prepared via aqueous sol-gel chemistry. Carbon aerogels are considered for numerous applications such as separation media in HPLC, as supercapacitors, as materials for hydrogen storage, as non-reflective materials, and as anodes in lithium-ion batteries. Meanwhile, porous carbons with high hydrophobic surface areas and large pore volumes are used as industrial adsorbents. In addition, macropores enhance mass transport for applicatoins in energy …
A Structural, Magnetic, And Mössbauer Spectral Study Of The Dyco₄₋ₓfeₓb Compounds, With X=0-3, Hervé Mayot, Olivier Isnard, Fernande Grandjean, Gary J. Long
A Structural, Magnetic, And Mössbauer Spectral Study Of The Dyco₄₋ₓfeₓb Compounds, With X=0-3, Hervé Mayot, Olivier Isnard, Fernande Grandjean, Gary J. Long
Chemistry Faculty Research & Creative Works
The DyCo4-xFexB compounds, with x=0, 1, 1.5, 2, 2.5, and 3, have been investigated by x-ray diffraction, magnetic measurements, and iron-57 Mössbauer spectroscopy. The substitution of cobalt by iron induces both an anisotropic increase in the unit-cell volume and a large increase in the Curie temperature. The 4.2 K magnetization decreases with increasing iron content. The Mössbauer spectra of the DyCo4-xFexB compounds with x=1, 1.5, and 2 reveal rather small iron hyperfine fields of approximately 16 T and large quadrupole interactions of +1.0 and -1.0 mms, for the 6i and 2c sites, …
Method Of Preparing A Chiral Substrate Surface By Electrodeposition, Jay A. Switzer, Hiten M. Kothari, Shuji Nakanishi, Eric W. Bohannan
Method Of Preparing A Chiral Substrate Surface By Electrodeposition, Jay A. Switzer, Hiten M. Kothari, Shuji Nakanishi, Eric W. Bohannan
Chemistry Faculty Research & Creative Works
A solid substrate comprising a surface comprising an achiral array of atoms having thereupon a chiral metal oxide surface. The chiral metal oxide surface is prepared by electrodeposition of a chiral metal oxide array from a solution of a chiral salt of the metal. In one embodiment, chiral CuO is grown on achiral Au(001) by epitaxial electrodeposition. The handedness of the film is determined by the specific enantiomer of tartrate ion in the deposition solution. (R,R)- tartrate produces an S—CuO(l 1 T) film, while (S,S)-tartrate produces an R—CuO(Tl 1) film. These chiral CuO films are enantiospecific for the electrochemical oxidation …
Synthesis And Characterization Of Two Metallic Spin-Glass Phases Of Femo₄Ge₃, Peter J. Baker, Peter D. Battle, Stephen J. Blundell, Fernande Grandjean, Thomas M. Lancaster, Gary J. Long, Sophie E. Oldham, Timothy John Prior
Synthesis And Characterization Of Two Metallic Spin-Glass Phases Of Femo₄Ge₃, Peter J. Baker, Peter D. Battle, Stephen J. Blundell, Fernande Grandjean, Thomas M. Lancaster, Gary J. Long, Sophie E. Oldham, Timothy John Prior
Chemistry Faculty Research & Creative Works
Polycrystalline samples of FeMo4Ge3 have been synthesized by the reduction of an oxide mixture at 1248 K and characterized by a combination of diffraction, muon spin relaxation (µ+SR), Mössbauer spectroscopy, magnetometry, transport, and heat-capacity measurements. The compound adopts a tetragonal W5Si3 structure (space group I4/mcm); the iron and molybdenum atoms are disordered over two crystallographic sites, 16k and either 4a or 4b. The synthesis conditions determine which fourfold site is selected; occupation of either leads to the presence of one-dimensional chains of transition metals in the structure. In both cases, …
Structural Evolution Of Ammonia Borane For Hydrogen Storage, Jinbo Yang, Jagat Lamsal, Qingsheng Cai, William B. Yelon, William Joseph James
Structural Evolution Of Ammonia Borane For Hydrogen Storage, Jinbo Yang, Jagat Lamsal, Qingsheng Cai, William B. Yelon, William Joseph James
Physics Faculty Research & Creative Works
We have studied the crystal structure of fully deuterated BH3NH3 using powder neutron diffraction at different temperatures. It is evident that an order-disorder phase transition occurs around 225 K. At low temperature, the compound crystallizes in the orthorhombic structure with space group Pnm21 and gradually transforms to a high temperature tetragonal structure with space group I4 mm above 225 K. At 16 K, the BD3-ND3 unit stacks along the c axis with a tilt angle of about 16° between the N-B bond and the c axis. As the temperature is increased, the BD3-ND3 groups start to reorient along the c …
The Decomposition Of Yba₂Cu₃O₇₋Δ Doped Into Ba₂Yruo₆, H. A. Blackstead, William B. Yelon, M. Kornecki, M. P. Smylie, P. J. Mcginn, Jinbo Yang, Qingsheng Cai, William Joseph James
The Decomposition Of Yba₂Cu₃O₇₋Δ Doped Into Ba₂Yruo₆, H. A. Blackstead, William B. Yelon, M. Kornecki, M. P. Smylie, P. J. Mcginn, Jinbo Yang, Qingsheng Cai, William Joseph James
Physics Faculty Research & Creative Works
One of the persistent criticisms of claims for observation of superconductivity in Ba2YRu1−uCuuO6 (O6) is that the diamagnetism is actually due to the decomposition of the material into YBa2Cu3O7−delta and other phases. We report a series of experiments in which YBa2Cu3O7−delta is doped into Ba2YRuO6 and carried through a series of sintering steps which were followed by magnetization, neutron diffraction, and scanning electron microscopy/microprobe measurements. It was found that the dopant YBa2Cu3O7−delta decomposed and failed to reform with cooling. It is concluded that the O6 phase is the stable high-temperature phase. The Cu released from the Y123 decomposition doped the …
Colossal Positive Magnetoresistance In A Doped Nearly Magnetic Semiconductor, Rongwei Hu, Karin Jessica Thomas, Yong Jae Lee, Thomas J. Vogt, Eun Sang Choi, Vesna F. Mitrovic, Raphäel P. Hermann, Fernande Grandjean, Paul C. Canfield, Jong Woo Kim, Alan I. Goldman, Cedomir Petrovic
Colossal Positive Magnetoresistance In A Doped Nearly Magnetic Semiconductor, Rongwei Hu, Karin Jessica Thomas, Yong Jae Lee, Thomas J. Vogt, Eun Sang Choi, Vesna F. Mitrovic, Raphäel P. Hermann, Fernande Grandjean, Paul C. Canfield, Jong Woo Kim, Alan I. Goldman, Cedomir Petrovic
Chemistry Faculty Research & Creative Works
We report on a positive colossal magnetoresistance (MR) induced by metallization of FeSb2, a nearly magnetic or “Kondo” semiconductor with 3d ions. We discuss the contribution of orbital MR and quantum interference to the enhanced magnetic field response of electrical resistivity.
Adhesion Enhancement Of Polymeric Films On Glass Surfaces By A Silane Derivative Of Azobisisobutyronitrile (Aibn)., Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Adhesion Enhancement Of Polymeric Films On Glass Surfaces By A Silane Derivative Of Azobisisobutyronitrile (Aibn)., Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Chemistry Faculty Research & Creative Works
Adhesion of polymeric films on surfaces can be due to a combination of van der Waals, electrostatic or covalent interactions between the two materials. The interfacial adhesion between a polymer film and glass or metal can be improved by using a broad class of silane coupling agents. Typically, silane coupling compounds used for adhesion improvement have structure similar to (R´O)3-Si-R, where R´O- is an alkoxy group and -R is an organofunctional group. Under appropriate reaction conditions alkoxy groups condense with hydroxyl groups available on the surface, resulting in surfaces decorated with organofunctional -R groups, which promote formation of covalent bonding …
Compressive Behavior Of Crosslinked Mesoporous Silica Aerogels At High Strain Rates, Hongbing Lu, H. Luo, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Compressive Behavior Of Crosslinked Mesoporous Silica Aerogels At High Strain Rates, Hongbing Lu, H. Luo, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis
Chemistry Faculty Research & Creative Works
Aerogels are low-density mesoporous materials with exceptionally low dielectric constants, low thermal conductivities (up to 40 times better thermal insulators than the best fiberglass) and high acoustic impedance. Their practical applications, however, have been slow due to their hydrophilicity and brittleness. The fragility problem was resolved by nanocasting a ~2-4 nm thick polymer layer on the skeletal silica nanoparticles that strengthens the weak inter-nanopartical necks. The thin polymer coats conformally the skeletal framework without clogging the mesopores and reinforces the structure by chemically crosslinking the nanoparticles. With a density increase by only three times, crosslinking aerogels have the flexural strength …
Synthesis And Evaluation Of Vegetable (Soybean) Oil Based Epoxy Resin For Beverage Can Coating And Enzymatic Synthesis And Characterization Of Tailored N&C End Protected Oligopeptides, Ying Gao
Doctoral Dissertations
"Research described in this dissertation covers two topics. Part-I is related to the development of a soybean oil based epoxy resin and its application in beverage can coatings. Interior surfaces of beverage can are invariably coated with polymer coating. The most commonly used coatings at present are derived from bisphenol A (BPA) based epoxy reins. However, due to perceived endocrine disrupting nature of BPA and consequential adverse effects on humans and wildlife concerns for the use of BPA based coatings and its leaching into beverages have been expressed. The research in the first part describes the synthesis and evaluation of …
Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat
Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat
Masters Theses
"Obscurants have been used for centuries to conceal and protect military assets from direct enemy attack, or as a signal between units. Obscurants still play a significant role in protecting soldiers on the battlefield. This research was geared towards development of highly efficient man portable obscurant generation system to demonstrate its use with biogenic oils as the obscurants. The research reported in the thesis was directed evaluating the performance of a mini-jet based generator in the laboratory and field with two different obscurant oils, Fog Oil (FO) the oil used by the US Army at present and potential replacement oil …
Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil
Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil
Masters Theses
"Crosslinking of aerogels is a promising approach to combine the advantages of inorganic and polymeric materials. In the present study, two types of polyimide-silica hybrid aerogels, APTES-BTDA-MDA (mol ratio: 2:2:1) and APTES-BTDA-MDA (mol ratio: 2:3:2), were synthesized using a sol-gel process followed by heating in order to imidize the polyamic acid that is formed quickly and is covalently bonded to silica. The hybrid aerogels were made using 3-aminopropyltriethoxysilane (APTES) endcapped polyamic acids and tetramethoxysilane (TMOS) as precursors. Polyimide crosslinked aerogels were characterized by TGA, SEM, FT-IR, BET, solid state NMR and gas pycnometry. These hybrid aerogels exhibit high thermal stability …
Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum
Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum
Chemistry Faculty Research & Creative Works
Ultra-thin polymer films attached to solid substrates (supported films) have attracted significant interest in recent years. Supported films are used in the design of advanced materials like photoresists, lubricants and other electronic devices. Glass transition temperatures (Tgs) of supported polymer films have also been of significant interest. The Tg has been shown to depend on the thickness of the polymer film on the surface and the inherent nature of the surface. The effect of end-grafting of a polymer chain to a surface, on the Tg of the polymer has been studied previously.1 Reports on the study of glass transition behaviors …
Polyaniline Nanofiber-Based Gas Sensors, Zhe-Fei Li, Frank D. Blum, Massimo F. Bertino, Chang-Soo Kim
Polyaniline Nanofiber-Based Gas Sensors, Zhe-Fei Li, Frank D. Blum, Massimo F. Bertino, Chang-Soo Kim
Chemistry Faculty Research & Creative Works
There has been recent interest in conducting polymers that have very promising chemical and electrical applications. Some of these polymers have shown great potential for use in sensors.1 Polyaniline is one particular example of a prospective material. In our laboratory, we have studied the synthesis of polyaniline nanofibers. We have carried out one-pot syntheses to obtain polyaniline nanofibers in aqueous solutions where the polymerization was influenced by γ-radiation2 or UV-radiation.3 This polymer can also be patterned with an appropriate photo mask. In our present report, polyaniline nanofiber thin film sensors have been fabricated in one step by employing UV-irradiation and …
A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski
A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski
Masters Theses
"Alpha hydroxy acids (AHAs) - carboxylic acids with a hydroxyl substitution on the alpha carbon are an important class of molecules. Hydroxy Methyl Thiobutanoic Acid (HMTBA) is an α-hydroxy analog of essential amino acid methionine; it finds extensive use as a feed supplement for avian and bovine species. Efficacy of alpha hydroxy acid uptake is important for nutritional studies and such studies rely on accurate and precise methods for determination of these chemicals in biological samples. Several methods for AHAs determination have been reported, however, the methods are tedious, requiring multiple sample preparation steps. Experiments reported in this thesis were …
X-Ray Lithography Of Metal And Semiconductor Nanoparticles, Nicholas Leventis, Suchi Guha, Massimo F. Bertino, Raghuveer Reddy Gadipalli, Brian R. Heckman, John Katsoudas, Ralu Divan, Lane A. Martin, Derrick C. Mancini
X-Ray Lithography Of Metal And Semiconductor Nanoparticles, Nicholas Leventis, Suchi Guha, Massimo F. Bertino, Raghuveer Reddy Gadipalli, Brian R. Heckman, John Katsoudas, Ralu Divan, Lane A. Martin, Derrick C. Mancini
Physics Faculty Research & Creative Works
In the last few years, a considerable amount of research has focused on the three-dimensional fabrication of contacts and electronic devices. Most techniques, however, are essentially based on photoreduction, and are limited to noble- and semi-noble metals. We present here a general method that allows patterning of porous matrices in 3D with metal, but also with semiconductor nanoparticles which is of potential relevance for microfabrication applications. In our method, the pore-filling solvent of a sol-gel material is exchanged with a solution of precursors. The precursors are photodissociated and nanoparticles are formed when the monoliths are irradiated. In a series of …
Thermal Analysis Of Adsorbed Poly(Vinyl Acetate) On Silica, Boonta Hetayothin, Frank D. Blum
Thermal Analysis Of Adsorbed Poly(Vinyl Acetate) On Silica, Boonta Hetayothin, Frank D. Blum
Chemistry Faculty Research & Creative Works
The physical properties of polymers at interfaces can be quite different from those in bulk due to the interaction between the absorbed polymer and the surface. This phenomenon can be probed through the dynamic behavior of the polymer chains at the interface which can be experimentally probed by techniques such as nuclear magnetic resonance spectroscopy (NMR),1 viscoelasticity, and calorimetry. At the polymer-air interface, polymer chains have more flexibility than those at the polymer-substrate interface. On the other hand, at the silica-polymer interface, where chains are more restricted on the surface, a higher glass transition temperature (Tg) results as compared with …
The Effect Of Free Chlorine And Monochloramine On Lead In Drinking Water And Epitaxial Electrodeposition Of Tin Sulfide, Sansanee Boonsalee
The Effect Of Free Chlorine And Monochloramine On Lead In Drinking Water And Epitaxial Electrodeposition Of Tin Sulfide, Sansanee Boonsalee
Doctoral Dissertations
"Electrochemical deposition is utilized in various electronic and photovoltaic applications and in the protective coating industries. This dissertation primarily addresses the environmental aspects of electrochemical deposition. In the first part of this study, Pb dissolution in drinking water was investigated in the presence of two disinfectants: free chlorine (in the form of HOCI/OCr) and monochloramine (NH₂Cl). In the second part of this study, epitaxial SnS nanodisks were electrodeposited onto a Au(100) substrate. Water utility systems use either free chlorine or monochloramine in their disinfection program. Whereas free chlorine reacts with natural organic matter in the water to produce halogenated organic …
Simulation Of The Evolution Of The Nanostructure Of Crosslinked Silica-Aerogels Under Compression, Hongbing Lu, Boshen Fu, Nitin Daphalapurkar, Jay Hanan, Nicholas Leventis, Chariklia Sotiriou-Leventis
Simulation Of The Evolution Of The Nanostructure Of Crosslinked Silica-Aerogels Under Compression, Hongbing Lu, Boshen Fu, Nitin Daphalapurkar, Jay Hanan, Nicholas Leventis, Chariklia Sotiriou-Leventis
Chemistry Faculty Research & Creative Works
Silica-aerogels are ultra-low-density assemblies of silica nanoparticles, and possess superior acoustic, specific energy absorption and thermal insulation properties. A new class of aerogels encapsulated with polymer is classified as crosslinked silica-aerogels. Manufacturing of such crosslinked silica-aerogel structures, depending on the type and shape of the nanoparticles, the polymer cross-linker and the chemistry in use, yields structures with vastly different morphologies and a wide range of mechanical behavior. With this, it has become necessary to understand the nanostructure / macroscopic properties relationship. Modeling of the aerogel material properties from mesoscale and up approach is needed, which is not considered by the …
Assemblies Of Nanoparticles As 3d Scaffolds For New Materials Design: From Polymer Crosslinked Aerogels To Polymer Matrix Composites, Nicholas Leventis, Chariklia Sotiriou-Leventis, Sudhir Mulik, Vishal U. Patil, Dhairyashil Mohite, Yanli Zhang, Hongbing Lu
Assemblies Of Nanoparticles As 3d Scaffolds For New Materials Design: From Polymer Crosslinked Aerogels To Polymer Matrix Composites, Nicholas Leventis, Chariklia Sotiriou-Leventis, Sudhir Mulik, Vishal U. Patil, Dhairyashil Mohite, Yanli Zhang, Hongbing Lu
Chemistry Faculty Research & Creative Works
From a materials perspective, nanotechnology furnishes materials with useful macroscopic properties by manipulating matter in the 1-100 nm size regime. Improvements in performance in terms of strength, modulus and wetability are accomplished by, for example, introducing nanoparticles as fillers in plastics . Two issues that usually interfere with optimal materials performance are agglomeration of the nanoparticles and materials compatibility. Agglomeration cancels the advantage of using nanoparticulate matter as dopant, while lack of materials compatibility introduces a discontinuity at the polymer/dopant interface from where failure may begin. Agglomeration is encountered with surfactants that keep nanoparticles dispersed, while materials compatibility is improved …
Dynamics Of Adsorbed Pma-D₃ - Effect Of Substrate, Frank D. Blum, Burak Metin, Macduff O. Okuom
Dynamics Of Adsorbed Pma-D₃ - Effect Of Substrate, Frank D. Blum, Burak Metin, Macduff O. Okuom
Chemistry Faculty Research & Creative Works
In the last few years, our group has focused much of our attention on studying the dynamics of polymers adsorbed at interfaces. Much of our work, to date has been on labeled poly(vinyl acetate)-d3 (PVAc-d3)1 and poly(methyl acrylate)-d3 (PMA-d3)2 on silica. We have been able to probe the effects of adsorbed amount,3 molecular mass,4,5 and the effect of overlayer.6 These studies have provided a view of the adsorbed polymer consistent with a motional gradient in the layer with the more mobile segments being those at the air-polymer interface and the less-mobile segments at the substratepolymer interface. However, we have not …
Dynamics Of Pipa-D₇ On Silica Surface, Piyawan Krisanangkura, Frank D. Blum
Dynamics Of Pipa-D₇ On Silica Surface, Piyawan Krisanangkura, Frank D. Blum
Chemistry Faculty Research & Creative Works
Molecular motion of polymer chains is an important determinant in understanding the physical properties of polymeric materials. Glass transition temperature (Tg) is a physical property of polymers, which is of primary interest. The study of the dynamics of polymer segments assists in understanding the dependence of Tg on polymer structure.1 For decades, studies have addressed the molecular motion in various polymers. Some of them have probed the dynamics of polymer backbones.2,3 the properties of a polymer at an interface may change because of the type of polymer, the substrate, or other variables. The side chain of a polymer can also …
A Tour-De-Force In Polymer Crosslinked Aerogels, Sudhir Mulik
A Tour-De-Force In Polymer Crosslinked Aerogels, Sudhir Mulik
Doctoral Dissertations
"In the quest of building mechanically strong materials with low density and high porosity, polymer crosslinked aerogels stand as the most promising nano-engineered examples. Covalent attachment of polymers and bridging of skeletal nanoparticles of typical aerogels is demonstrated by using surface initiated polymerization (SIP) with a bidentate free-radical initiator structurally related to azobisisobutyronitrile (AIBN) and confined on mesoporous silica surfaces. Different monomers were introduced in the mesopores and upon heating at 70⁰C, all mesoporous surfaces throughout the entire skeletal framework were coated conformally with a 10-12 nm thick polymer layer indistinguishable spectroscopically from the respective commercial bulk materials. The new …