Chemical Engineering Commons^™

A Novel Silica-Based Nano Pigment As A Titanium Dioxide Replacement, Ryan Stoneburner

Masters Theses

This research focused on the evaluation of a new Silica-based pigment for the replacement of titanium dioxide (TiO₂) in paperboard coatings. The silica-based pigment has shown the ability to be a replacement in terms of functionality and runnability. TiO₂ is currently the highest opacifying pigment used in paper coatings, but it is also the most costly. Finding a less expensive pigment that doesn't reduce effectiveness is critical to reducing the cost of TiO₂ formulations. To evaluate the new pigment, coatings will be applied using a Cylindrical Laboratory Coater (CLC) with varying amounts of TiO₂ and …

Graphene-Supported Metal Nanoparticles And Its Potential Civilian And Military Applications, Hany A. Elazab Dr

Chemical Engineering

It is now well established that nanoparticles (1-100 nm) exhibit unique chemical and physical properties that differ from those of the corresponding bulk materials. The dependence of the properties of nanoscale materials on the size, shape and composition of the nanocrystal is a phenomenon of both fundamental scientific interest and many practical and technological applications. These properties are often different, and sometimes superior, to those of the corresponding bulk materials. Due to its unique properties and high surface area, Graphene has become a good candidate as an effective solid support for metal catalysts. The Nobel Prize in Physics for 2010 …

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …

Electrocatalytic Processing Of Renewable Biomass-Derived Compounds For Production Of Chemicals, Fuels And Electricity, Le Xin

Dissertations, Master's Theses and Master's Reports - Open

The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with …

Gold-Magnetite Nanoparticle-Biomolecule Conjugates: Synthesis, Properties And Toxicity Studies, Akshay Pariti

Masters Theses

"This thesis study focuses on synthesizing and characterizing gold-magnetite optically active magnetic nanoparticle and its conjugation with biomolecules for biomedical applications, especially magnetic fluid hyperthermia treatment for cancerous tissue. Gold nanoparticles have already displayed their potential in the biomedical field. They exhibit excellent optical properties and possess strong surface chemistry which renders them suitable for various biomolecule attachments. Studies have showed gold nanoparticles to be a perfect biocompatible vector. However, clinical trials for gold mediated drug delivery and treatment studied in rat models identified some problems. Of these problems, the low retention time in bloodstream and inability to maneuver externally …

Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li

Journal of Electrochemistry

Dispersed spherical Fe₃O₄ nanoparticles were synthesized by a hydrothermal method. The influences of odecyl trimethyl ammonium bromide (DTAB) concentration on the morphology and particle size of the as-prepared Fe₃O₄ were studied. Electrochemical performance of the as-prepared sample as anode materials of lithium ion battery was investigated. It is found that the as-prepared sample exhibits superior rate performance and cycle performance. The nano-sized materials provide structural stability and favor the transfer of lithium ions.

Binding, Transcytosis And Biodistribution Of Anti-Pecam-1 Iron Oxide Nanoparticles For Brain-Targeted Delivery, Mo Dan, David B. Cochran, Robert A. Yokel, Thomas D. Dziubla

Pharmaceutical Sciences Faculty Publications

OBJECTIVE: Characterize the flux of platelet-endothelial cell adhesion molecule (PECAM-1) antibody-coated superparamagnetic iron oxide nanoparticles (IONPs) across the blood-brain barrier (BBB) and its biodistribution in vitro and in vivo.

METHODS: Anti-PECAM-1 IONPs and IgG IONPs were prepared and characterized in house. The binding affinity of these nanoparticles was investigated using human cortical microvascular endothelial cells (hCMEC/D3). Flux assays were performed using a hCMEC/D3 BBB model. To test their immunospecificity index and biodistribution, nanoparticles were given to Sprague Dawley rats by intra-carotid infusion. The capillary depletion method was used to elucidate their distribution between the BBB and brain parenchyma.

RESULTS: Anti-PECAM-1 …

Batch And Continuous Production Of Stable Dense Suspensions Of Drug Nanoparticles In A Wet Stirred Media Mill, Afolawemi Afolabi

Dissertations

One way to improve the bioavailability of poorly water-soluble drugs is to reduce particle size of drug crystals down to nanoscale via wet stirred media milling. An increase in total surface area per mass loading of the drug and specific surface area as well as reduced external mass transfer resistance allow a faster dissolution of the poorly-water soluble drug from nanocrystals. To prevent aggregation of nanoparticles, polymers and surfactants are dissolved in water acting as stabilizers via adsorption onto the drug crystals.

In the last two decades, ample experimental data were generated in the area of wet stirred media milling …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …

Applications Of Antioxidant And Anti-Inflammatory Polymers To Inhibit Injury And Disease, David B. Cochran

Theses and Dissertations--Chemical and Materials Engineering

There is an undeniable link between oxidative stress, inflammation, and disease. Currently, approaches using antioxidant therapies have been largely unsuccessful due to poor delivery and bioavailability. Responding to these limitations, we have developed classes of polymer and delivery systems that can overcome the challenges of antioxidant and anti-inflammatory therapy. In our initial studies, nanoparticles of poly(trolox), a polymeric form of trolox, were surface-modified with antibodies. This modification allows for specific targeting to endothelial cells, affording controllable and localized protection against oxidative stress. We have shown these targeted nanoparticles bind, internalize, and provide protection against oxidative stress generation and cytotoxicity from …

Novel Microwave Assisted Synthesis Of Zns Nanomaterials, Suresh Pillai, Michael Seery, Damian Synnott, John Colreavy, Stephen Hinder

Articles

A novel ambient pressure microwave-assisted technique is developed in which silver and indium modified ZnS is synthesised. The as prepared ZnS is characterised by X-ray diffraction, UV-Vis spectroscopy, X-ray photoelectron spectroscopy and luminescence spectroscopy. This procedure produced crystalline materials with particle sizes below 10 nm. The synthesis technique leads to defects in the crystal which induce mid energy levels in the band gap and lead to indoor light photocatalytic activity. Increasing the amount of silver causes a phase transition from cubic blende to hexagonal phase ZnS. In a comparative study, when the ZnS cubic blende is heated in a conventional …

Gravure Printability Of Indium Tin Oxide Nanoparticles On Glass And Pet Films For Applications In Printed Electronics, Dania Awni Alsaid

Dissertations

The advancements in the field of solution processable electro-active materials and their ability to be printed on different substrates have led to the evolution of printed electronics. In this field, electronic components are manufactured with conventional printing methods. Transparent electrodes made from indium tin oxide (ITO) are part of many electronic devices. Currently in industry, highly conductive ITO films are prepared by sputtering. The sputtering and then patterning of ITO films is a sophisticated process that consumes high energy, generates waste and produces films with limited flexibility. Therefore, there is a need to investigate processing methods for creating ITO films …

Refractive Index Chemical Sensing With Noble Metal Nanoparticles, Phillip Blake

Graduate Theses and Dissertations

Chemical sensing is a key component in modern society, especially in engineering applications. Because of their widespread impact, improvements to chemical sensors are a significant area of research. One class of sensors, plasmonic sensors, is being heavily researched because of their ability to detect low levels of analyte in near real time without destroying the analyte. This work studies a new class of plasmonic sensor that utilizes diffractive coupling to improve sensor performance. Specifically, this work outlines the first study of diffractive coupling sensors with typical nanoparticle shapes. Sensitivity of this new class of sensor is directly compared to typical …

Rat Brain Pro-Oxidant Effects Of Peripherally Administered 5 Nm Ceria 30 Days After Exposure, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Rebecca L. Florence, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield

Chemistry Faculty Publications

The objective of this study was to determine the residual pro-or anti-oxidant effects in rat brain 30 days after systemic administration of a 5 nm citrate-stabilized ceria dispersion. A ∼4% aqueous ceria dispersion was iv-infused (0 or 85 mg/kg) into rats which were terminated 30 days later. Ceria concentration, localization, and chemical speciation in the brain was assessed by inductively coupled plasma mass spectrometry (ICP-MS), light and electron microscopy (EM), and electron energy loss spectroscopy (EELS), respectively. Pro- or anti-oxidant effects were evaluated by measuring levels of protein carbonyls (PC), 3-nitrotyrosine (3NT), and protein-bound-4-hydroxy-2-trans-nonenal (HNE) in the hippocampus, cortex, and …

Fabrication Of Printed Substrate For Surface Enhanced Raman Spectroscopy, Ali Eshkeiti

Masters Theses

A novel surface enhanced Raman spectroscopy (SERS) substrate was successfully fabricated on a silicon wafer using inkjet printing and on polyethylene terephthalate (PET) using gravure printing. Silver (Ag) nanoparticle (NP) based ink, was used for roughening of the surface of silicon and PET. A thickness of 400 nm was measured for the printed Ag NP printed film on silicon and the thickness of the single and double layered films on PET were measured as 340 nm and 680 nm, respectively by using vertical scanning interferometry. The Ag NP printed SERS substrate was tested for application with heavy metal compounds like …

Electrochemical Deposition Of Ag-Sn Nanoparticles For Photovoltaic Current Collection Efficiency, Rebecca Wilson

Honors Theses and Capstones

Photovoltaic cells utilize a semiconductor to harness the sun's energy, then conduct the energy by silver current collector lines to an energy storage device. To make photovoltaic cells less expensive and more energy efficient, silver-tin nanoparticles were researched to incorporate into the silver polymer paste that makes up current collector lines. The Ag-Sn alloy was synthesized by electrochemical deposition, and was then characterized by it's melting point and crystal structure.

Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

The modification of a glassy carbon (GC) electrode with platinum (PtNPs) and gold (AuNPs) nanoparticles is targeted to fabricate efficient anodes for the electrooxidation of formic acid (FA). A proper adjustment of the deposition sequence of PtNPs and AuNPs could eventually enhance the electrocatalytic activity of the electrode in such a way that suppresses the CO poisoning effect during FA oxidation. The highest catalytic activity is obtained at the Au/Pt/GC electrode (with PtNPs firstly deposited on the GC electrode followed by AuNPs). This superb enhancement is quantified by comparing the relative ratio of the direct vs. the indirect oxidation peaks …

Design Of Colloidal Composite Catalysts For Co2 Photoreduction And For Co Oxidation, Bijith D. Mankidy

USF Tampa Graduate Theses and Dissertations

In this doctoral dissertation, novel colloidal routes were used to synthesize nanomaterials with unique features. We have studied the impact of nanoparticle size of catalyst, role of high surface area of a photocatalyst, and the effect of varying elemental composition of co-catalytic nanoparticles in combination with core-shell plasmonic nanoparticles. We have demonstrated how physical and chemical characteristics of nanomaterials with these unique features play a role in catalytic reactions, specifically the oxidation of CO and the photoreduction of CO2. The first objective of this doctoral dissertation involved the preparation of CoO nanoparticles with discrete nanoparticles sizes (1-14 nm) using a …

Novel Routes For Synthesis Of Pd Nanoparticles And Faceted Zno Supports For Heterogeneous Catalysts, Patrick David Burton

Chemical and Biological Engineering ETDs

Alcohol steam reforming is a promising source of hydrogen as fuel, and could be improved by the use of an optimal catalyst. The methanol steam reforming reaction, CH3OH+H2O --> 3H2+CO2 frequently conducted by means of a Cu/ZnO catalyst. Unfortunately, this catalyst deactivates quickly and is pyrophoric. Pd catalysts are much more stable, but reactions using these catalyst follow the decomposition pathway, CH3OH --> 2H2+CO. PdZn alloys can achieve the desired selectivity, and have been noted to form under reaction conditions from Pd/ZnO heterogeneous catalysts. In the present work, careful synthesis techniques of specific support and nanoparticle surfaces have been developed …

Boron And Rare Earth Oxide Composite Nanoparticles For Enhancement Of Combustion, Jacob Hanberry

LSU Master's Theses

Metallic fuels are of interest as additives in bio-fuel combustion because of their high heating values, and this thesis deals with the experimental investigation of boron nanoparticles and their effect on ethanol combustion. Two grades of boron nanoparticles were commercially purchased and modified to obtain different physical characteristics, by ball milling and sintering. Also, a mixture of rare-earth oxide (CeO2, La2O3, and Gd2O3) nanoparticles was synthesized and added to the boron nanoparticles in varying amounts to form composite mixtures. The effects of rare-earth oxides on boron combustion were investigated using these composites. Particle characterizations were carried out by X-ray diffraction, …

Effect Of Titanium Dioxide Supports On The Activity Of Pt-Ru Toward Electrochemical Oxidation Of Methanol, Roderick E. Fuentes, Brenda L. García, John W. Weidner

Faculty Publications

TiO₂and Nb-TiO₂ were investigated as stable supports for Pt-Ru electrocatalysts towards methanol oxidation. X-ray photo-electron spectroscopy (XPS) data for all these TiO₂-based supports show oxidation states of Ti⁴⁺, with no Ti³⁺, suggesting low electronic conductivity. However, the deposition of metal nanoparticles onto the supports at loadings of 60 wt% metal dramatically increased conductivity, making these electrodes (metal particles + support) suitable for electrochemistry even though the supports have low conductivity. For some of these TiO₂-based supports, the activity of Pt-Ru towards methanol oxidation was excellent, even surpassing the activity …

Catalytic Hydrogenation Of Co To Higher Alcohols, Nachal Devi Subramanian

LSU Doctoral Dissertations

The interest in converting synthesis gas to alcohols and oxygenated fuel additives via CO hydrogenation is growing rapidly due to the increasing rise in oil prices. Among the potential end products, ethanol is desirable since it serves as a clean alternative fuel, a gasoline blend, and a hydrogen carrier to supply fuel cells. The high cost and limited availability of the most active/selective Rh-based catalysts has led to the development of base metal catalysts such as modified Cu-based catalysts. Literature suggests that a combination of Co (or Mn) with Cu can facilitate higher alcohol formation by a non-dissociative adsorption of …

The Sintering And Stability Of Catalytic Nano-Particles, Andrew Delariva

Chemical and Biological Engineering ETDs

Studies were performed on three different catalysts in order to determine their stability and sintering behavior. Pd deposited on a flat single crystal substrate made of Al2O3 was characterized to determine if the mechanism of Ostwald ripening was solely dominated by vapor phase transport of metal atoms. The atoms emitted could be determined by the rate of evaporation and an attempt was then made in order to relate the rates of emission to sintering (instability of nanoparticles). It was found that the rates of emission did not fully reflect vapor phase transport (direct evaporation). The particle-support interaction was increasing the …

Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The fluidization of nanoparticle agglomerates can be largely improved by using downward pointing micronozzles, creating a high-velocity jet, as experimentally shown. By discrete particle simulations – treating the agglomerates as single particles – we show that the main reason is probably the reduction of the agglomerate size by agglomerate-agglomerate collisions.

Fluidization Of Nanopowders: Experiments, Modeling, And Applications, J. Ruud Van Ommen, Robert Pfeffer

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Nanopowders are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process nanoparticles. However, nanoparticles cannot be fluidized individually; they fluidize as very porous agglomerates. Often, it is needed to apply an assisting method, such as vibration or microjets, to obtain proper fluidization. In this paper, we give a brief review of the developments in nanopowder fluidization.

Mesoporous Tin Oxide As An Oxidation-Resistant Catalyst Support For Proton Exchange Membrane Fuel Cells, Peng Zhang, Sheng-Yang Huang, Branko N. Popov

Faculty Publications

Mesoporous catalyst support based on tin oxide (SnO₂) is synthesized with high surface area of 205 m² g⁻¹ and with narrow pore size distribution. Modified polyol method is used to deposit platinum on SnO₂. The physical properties of the support and the SnO₂-supported Pt catalyst (Pt/SnO₂) are characterized by using the Brunauer, Emmett, and Teller method, X-ray diffraction, and transmission electron microscopy. The electrochemical stability and durability of the Pt/SnO₂ catalyst are investigated by the accelerated stress tests proposed by the U.S. Department of Energy. Pt/SnO₂ catalyst exhibits …

Precipitation Of Micro/Nanoparticles In Enhanced High Energy Dissipation Mixing Systems, Giuseppe Di Benedetto

Dissertations

Crystallization is the most common unit operation used in the pharmaceutical industry to synthesize active ingredients. Rapid development of a drug candidate is dependent on the ability to produce a desired drug substance with consistent properties, These properties include stability and purity, which are directly affected by the crystallization process and which affect, in turn, bioavailability, drug dissolution rate, drug stability, and shelf life.

The objective of this work is to produce micro/nanoparticle crystals within existent glass-lined pharmaceutical stirred-tank reactors by modifying the current reactor configuration to include features that can increase the local rate of energy dissipation in the …

Enhanced Fluidization Of Nanoparticle Agglomerates, Daniel Lepek

Dissertations

Gas fluidization of nanoparticle agglomerates has recently received much attention due to the excellent way in which these novel nanornaterials can be dispersed in a gaseous medium. Nanopowders have a very high surface area to volume ratio which allows them have unique chemical and physical properties especially at the surface. Fluidization is a popular technique for the continuous dispersal of solid materials in the fluidlike state.

Recently it has been found that nanoparticles exist in a highly agglomerate state which allow them to become fluidizable. The fluidization behavior of the nanopowders is dependent on the bulk and material properties of …

Particle-Chemical Interactions And Environmental Chemodynamics Of Fine And Ultrafine Particles In A Natural Disaster Scenario, Nicholas A. Ashley

LSU Doctoral Dissertations

The interactions of fine and ultrafine particles with chemicals play a dominant role in determining the mobility and availability of pollutants in the environment. Fine particles in sediments can sequester chemicals from the water column, and release volatile and semi-volatile organic compounds to the gas phase upon exposure to air. Ultrafine particles which are photoreactive can degrade these vapor-phase contaminants, and may transform the molecules into species which are more toxic or hazardous than the parent. As the widespread, commercial use of ultrafine particles becomes more common, understanding the chemodynamics of these particles and their interactions with chemicals in the …

Production Of Nanocrystalline Rdx By Ress : Development And Material Characterization, Victor Stepanov

Dissertations

The aim of the present work was to address the hazardous vulnerability of energetic materials to accidental initiation. An improved form of the explosive RDX with a significantly reduced sensitivity to stimuli including shock and impact was sought. The direction of this research was to investigate the effect of RDX crystal size reduction down to nano-scale dimensions on the sensitivity characteristics. Although size reduction of energetic crystals has been demonstrated often to result in a sensitivity reduction, the effect at the nano-scale particle size has not been investigated.

To generate nanocrystalline RDX a recrystallization process was developed based on rapid …