Nanoscience and Nanotechnology Commons^™

Utilizing Fluorescent Nanoscale Particles To Create A Map Of The Electric Double Layer, Quintus Owen

Theses and Dissertations

The interactions between charged particles in solution and an applied electric field follow several models, most notably the Gouy-Chapman-Stern model, for the establishment of an electric double layer along the electrode, but these models make several assumptions of ionic concentrations and an infinite bulk solution. As more scientific progress is made for the finite and single molecule reactions inside microfluidic cells, the limitations of the models become more extreme. Thus, creating an accurate map of the precise response of charged nanoparticles in an electric field becomes increasingly vital. Another compounding factor is Brownian motion’s inverse relationship with size: large easily …

Properties Of Titanium Dioxide Nanoparticles Aquesous Dispersions Stabilized By Anionic Surfactants, Anita Vuchkovska

Theses and Dissertations

The stability of titanium dioxide nanoparticles dispersed in aqueous solutions with and without anionic surfactants was investigated as a function of phase separation (sedimentation), particle size at the age of 33 and 303 days, polydispersity at 33 and 303 days, and zeta potential. Mechanical energy in the form of homogenization or mixing with propeller blade mixer was used to wet out the titanium dioxide (TiO2) nanoparticles in the aqueous media and this process was evaluated for the capability of developing a stable dispersion. The ultrasonic waves were used as a second step to form stable dispersions. The research results indicated …

Towards Environmental Sustainability Of Nanotechnology Through Improved Evaluations Of Impact And Risk To Aquatic Species: Cross-Species Comparisons From The Laboratory And Environmentally Realistic Exposure Scenarios In The Field, Becky J. Curtis

Theses and Dissertations

Engineered nanomaterials (ENMs) are utilized in a wide variety of applications and products, including everything from toothpaste and personal care products to industries such as aerospace, defense, medicine, electronics, and agriculture. Depending on the application, release of ENMs to the environment may occur through both unintentional and deliberate routes. High surface-area-to-volume ratios make ENMs more volatile than bulk counterparts, and their small size allows translocation within biological systems that would not be possible with larger materials. These and other characteristics make ENM-biological system interactions unpredictable, creating uncertainty about their potential risks to environmental health. The purpose of this research is …

Study Of The Chemical Fabrication Process Of Nsom Probes And The Modification Of The Probe Surface, Muhammad Nazmul Hussain

Theses and Dissertations

Near-field scanning optical microscopy (NSOM) merges scanning probe technology with the power of high-resolution optical microscopy and provides a natural view into the nanoworld. NSOM requires tapered probes with subwavelength optical apertures and wide cone angles to efficiently channel the illumination light to the tip apex so that it can acquire optical images beyond the diffraction limit. Tapered probes with a range of cone angles can be fabricated through chemical etching of optical fibers using hydrofluoric acid (HF) by varying the etching time. Apart from their use for NSOM imaging, such optical probes can also be transformed into nanosensors by …

Transport, Photoluminescence & Photoconduction Characteristics Of Free Standing Two-Dimensional Γ-Alumina & Titanium Superlattice Doped Two-Dimensional Γ-Alumina Grown By Graphene-Assisted Atomic Layer Deposition, Elaheh Kheirandish

Theses and Dissertations

This study presents a facile high-yield bottom-up fabrication, morphology, crystallographic and optoelectronic characterization of free-standing quasi-2D γ-alumina, a non van der Waals 2D material. The synthesis comprises a multi-cycle atomic layer deposition (ALD) of amorphous alumina on a porous interconnected graphene foam as a growth scaffold and removed next by annealing and sintering the alumina/graphene/alumina sandwich at ~ 800 °C in air . The crystallographic and structural characteristics of the formed non-van der Waals quasi 2D γ-alumina were studied by X-ray diffraction (XRD), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). This analysis revealed the synthesized 2D …

Investigating Mechanisms Of Nanotoxicity Of A Next-Generation Lithium Cobalt Oxide Nanomaterial, Nicholas Joseph Niemuth

Theses and Dissertations

Commercial use of engineered nanomaterials (ENMs; materials in the range of 1-100 nm) has grown dramatically since the discovery of the means to observe, characterize, and controllably synthesize these materials at the end of the 20th century. Today, ENMs represent a global market valued in the trillions of dollars, incorporated into products because of the unique properties they confer, including increased strength, catalytic activity, and interactions with light. In this time, ENMs have also grown from relatively simple first-generation materials, such as Au, Ag, and carbon ENMs, to complex next-generation materials incorporating numerous elements into materials with complex secondary structures, …

Novel Solar Cells Based On Two-Dimensional Nanomaterials And Recycled Lead Components, Xiaoru Guo

Theses and Dissertations

To meet the rapidly growing demand for energy and reduce the use of dwindling fossil fuels, the efficient utilization of renewable energy is a constant pursuit globally. Because solar cells convert vastly available sunlight into electricity, developing high-performance and low-cost solar cells is a top strategy for future energy supply. Dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs) are the most promising choices. In the meantime, highly concentrated sulfuric acids from retired lead-acid batteries become an environmental concern, and lead contamination in drinking water raises concerns in general public. This study addresses both above-mentioned problems by using two-dimensional (2D) …

Synthesis, Transport, And Thermoelectric Studies Of Topological Dirac Semimetal Cd3as2 For Room Temperature Waste Heat Recovery And Energy Conversion, Tahereh A. Hosseini

Theses and Dissertations

ABSTRACT

SYNTHESIS, TRANSPORT, AND THERMOELECTRIC STUDIES OF TOPOLOGICAL DIRAC SEMIMETAL CD3AS2 FOR ROOM TEMPERATURE WASTE HEAT RECOVERY AND ENERGY CONVERSION

by

The University of Wisconsin-Milwaukee, 2017

Under the Supervision of Professor Nikolai Kouklin

Rising rates of the energy consumption and growing concerns over the climate change worldwide have made energy efficiency an urgent problem to address. Nowadays, almost two-thirds of the energy produced by burning fossil fuels to generate electrical power is lost in the form of the heat. On this front, increasing electrical power generation through a waste heat recovery remains one of the highly promising venues of the …

Numerical And Experimental Studies Of Atomic Layer Deposition For Sustainability Improvement, Dongqing Pan

Theses and Dissertations

Atomic layer deposition (ALD) is an approved nano-scale thin films fabrication technique with remarkable uniformity and conformity in surface geometry. This dissertation presents numerical and experimental studies to investigate the transient physical and chemical ALD process in order to improve its sustainability performance in terms of throughput, wastes and emissions.

To be specific, in this dissertation, the transient process of ALD is studied extensively through both numerical and experimental approaches to find the influential factors on the two main critical sustainability issues: low throughput and negative environmental impacts. Different numerical schemes are developed and studied for ALD process simulations. In …

Effects Of Surface Topography And Vibrations On Wetting: Superhydrophobicity, Icephobicity And Corrosion Resistance, Rahul Ramachandran

Theses and Dissertations

Concrete and metallic materials are widely used in construction and water industry. The interaction of both these materials with water and ice (or snow) produces undesirable results and is therefore of interest. Water that gets absorbed into the pores of dry concrete expands on freezing and can lead to crack formation. Also, the ice accretion on concrete surfaces such as roadways can have disastrous consequence. Metallic components used in the water industry undergo corrosion due to contact with aqueous corrosive solutions. Therefore, it is desirable to make concrete water/ice-repellent, and to make metallic surfaces corrosion-resistant.

Recent advances in micro/nanotechnology have …

Novel Nanostructured Materials For Solar Fuel Production And Advanced Rechargeable Batteries, Cunyu Zhao

Theses and Dissertations

Non-renewable fossil fuels are the major sources to meet the energy, electricity and transportation demands of today's world. The over consumption of fossil fuels will lead to the increasing energy crisis and disastrous effects such as air pollution, global warming etc.

The primary greenhouse gas is CO2 mainly emits from the combustion of fossil fuels. Photocatalytic reduction of CO2 using sunlight as the energy input is a promising way to reduce CO2 level in the atmosphere and in the meantime produce alternative fuels such as CO, methane, methanol, etc. Among the various photocatalyst materials reported, nanomaterial TiO2 is the most …

Effect Of Relative Humidity In High Temperature Oxidation Of Ceria Nanoparticles Coating On 316l Austenitic Stainless Steel, Luis Giraldez Pizarro

Theses and Dissertations

A solution of 20 wt. % colloidal dispersion of Cerium Oxide (CeO2) in 2.5% of acetic acid, was used for depositing a coating film on an austenitic stainless steel 316L. Cerium compounds have been distinguished as potential corrosion inhibitors in coatings over several alloys. The oxidation behavior of the cerium oxide coating on 316L austenitic stainless steel alloy was evaluated in dry and humid environments, the weight changes (W/A) was monitored as a function of time using a custom built Thermogravimetrical Analysis (TGA) instrument at temperatures of 750C, 800C and 850C, and different relative humidity levels (0%, 10% and 20%) …

Fibrinogen-Conjugated Gold-Coated Magnetite Nanoparticles For Antiplatelet Therapy, Evan Schuerer Krystofiak

Theses and Dissertations

Ischemic stroke is the world's second leading cause of death and accounts for 2-4% of total worldwide healthcare costs. Ischemic stroke is caused by the occlusion of arteries responsible for supplying blood to the brain, which can result in disability or death. Arterial blood clots consist of aggregates of activated platelets wrapped in a mesh of fibrin. Tissue plasminogen activator, the only current FDA-approved treatment for ischemic stroke, functions by lysing fibrin in a blood clot. Unfortunately, tissue plasminogen activator significantly increases bleeding risks, which restricts its use. Alternatively, targeting and disrupting platelets within a clot could improve stroke outcome. …

Functional Organic Nanomaterials, Ryan R. Kohlmeyer

Theses and Dissertations

π-Conjugated polymers have a wide range of applications such as photovoltaics, light-emitting diodes, and sensors. To gain a better understanding of these systems, monodisperse oligomers can be used as a more simplistic model to generate predictive structural and physical properties of corresponding polymers. A divergent/convergent synthetic approach to synthesis of monodisperse π-conjugated oligomers has been developed. These well-defined, thiophene-containing molecular building blocks have been successfully coupled to a ferrocene hinge, which has been found to be highly efficient in the transport of gold atoms using a gold scanning tunneling microscopy tip.

Carbon nanotubes (CNTs) represent a rare class of materials, …

Development Of Nano-Zro2 Reinforced Self-Flowing Low And Ultra Low Cement Refractory Castables, Cem Gogtas

Theses and Dissertations

The main goal of this research is to develop high strength high toughness nano-ZrO2 reinforced self flow low cement (5%) and ultra low cement (3 and 1%) castables based on tabular alumina. In processing these castables, the Andreassen model was used to obtain optimum self flow properties in both, low and ultra low castables. The castables thus produced were fired at 110 and 1000, 1300 and 1500oC and the phases obtained were investigated by X-ray diffraction (XRD) including energy dispersive X-ray (EDX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). In addition, the other castable properties …