Nanoscience and Nanotechnology Commons^™

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes. …

Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee

Mechanical Engineering Research Theses and Dissertations

Solid‐state nanopore sensors have been used to measure the size of a nanoparticle by applying a resistive pulse sensing technique. Previously, the size distribution of the population pool could be investigated utilizing data from a single translocation, however, the accuracy of the distribution is limited due to the lack of repeated data. In this study, we characterized polystyrene nanobeads utilizing single particle recapture techniques, which provide a better statistical estimate of the size distribution than that of single sampling techniques. The pulses and translocation times of two different sized nanobeads (80 nm and 125 nm in diameter) were acquired repeatedly …

The Rheology And Roll-To-Roll Processing Of Shear-Thickening Particle Dispersions, Sunilkumar Khandavalli

Doctoral Dissertations

Particle dispersions are ubiquitous in our daily lives ranging from food and pharmaceutical products to inks. There has been great interest in the recent years in formulation of functional inks to fabricate myriad flexible electronic devices through high-throughput roll-to-roll technologies. The formulations often contain several functional additives or rheological modifiers that can affect the microstructure, rheology and processing. Understanding the rheology of formulations is important for tuning the formulation for optimal processing. This thesis presents investigations on the rheology of particle dispersions and their impact on roll-to-roll technologies. Shear-thickening behavior is common in particle dispersions, particularly, concentrated particulate inks. We …

Metal Sulfides As Anode For Lithium Ion And Sodium Ion Battery, Ali Abdulla

Electronic Thesis and Dissertation Repository

Abstract

Nanomaterials have been studied intensively in the last decades due to their unique physical and chemical properties and their potential for applications in different domains. Among these applications, energy storage has become the center of focus by many research groups and companies to develop high efficiency and reliable energy devices such as the commercial lithium ion batteries (LIBs). However, LIBs has not yet met the growing requirements of the high demand for increasing energy density. More efforts are requested to improve the performance of the batteries by designing better electrode materials and increasing the battery safety. Another type of …

Deformation Behavior Of Al/A-Si Core-Shell Nanostructures, Robert Andrew Fleming

Graduate Theses and Dissertations

Al/a-Si core-shell nanostructures (CSNs), consisting of a hemispherical Al core surrounded by a hard shell of a-Si, have been shown to display unusual mechanical behavior in response to compression loading. Most notably, these nanostructures exhibit substantial deformation recovery, even when loaded much beyond the elastic limit. Nanoindentation measurements revealed a unique mechanical response characterized by discontinuous signatures in the load-displacement data. In conjunction with the indentation signatures, nearly complete deformation recovery is observed. This behavior is attributed to dislocation nucleation and annihilation events enabled by the 3-dimensional confinement of the Al core. As the core confinement is reduced, either through …

Enhanced Visible Light Photocatalytic Remediation Of Organics In Water Using Zinc Oxide And Titanium Oxide Nanostructures, Srikanth Gunti

USF Tampa Graduate Theses and Dissertations

The techniques mostly used to decontaminate air as well as water pollutants have drawbacks in terms of higher costs, require secondary treatment, and some methods are very slow. So, emphasis has been given to water though the use of photocatalysts, which break organic pollutants to water and carbon dioxide and leave no trace of by-products at the end. Photocatalytic remediation aligns with the waste and wastewater industries’ zero waste schemes with lower cost, eco-friendly and sustainable treatment technology. The commonly used photocatalysts such as titanium oxide (TiO₂), zinc oxide (ZnO), tungsten oxide (WO₃) have band gap …

Optimization Of Reduced Graphene Oxide Deposition For Hydrogen Sensing Technologies, Matthew Pocta

Mechanical Engineering Undergraduate Honors Theses

Graphene is known to be a key material for improving the performance of hydrogen sensors. High electrical conductivity, maximum possible surface area with respect to volume, and high carrier mobility are a few of the properties that make graphene ideal for hydrogen sensing applications. The problem with utilizing graphene is the difficulty in depositing uniform, thin layers onto substrate surfaces. This study examines a new method of optimizing graphene deposition by utilizing an airbrush to deposit both graphene oxide (GO) and reduced graphene oxide (rGO) onto glass substrates. The number of depositions were varied among samples to study the effect …

Nanoscale Investigations Of Thermal And Momentum Transport In Graphene – Water Systems, Drew Champion Marable

Masters Theses

Demand for miniaturized electronic devices has given rise to new challenges in thermal management. Integration with graphene, a two-dimensional (2D) material with excellent thermal properties, allows for further reduced sizes and combats thermal management issues within novel devices. Moreover, due to its wide availability and adequate thermal properties, liquid water is commonly used within traditional thermal systems to enhance cooling performance; as such, water is expected to yield similar performance in smaller-scale applications. However, at reduced sizes descending to the nanoscale realm, system behaviors deviate from traditional macroscale-based theory as interfacial effects become amplified. Employing insight provided by molecular dynamics …

Nanotextured Titanium Surfaces For Implants: Manufacturing And Packaging Aspects, Sachin Bhosle

Dissertations, Master's Theses and Master's Reports

It has been shown that nanotexturing the surface of otherwise smooth titanium orthopedic materials increases osteoblast proliferation in vitro, and the bone-implant contact area and pullout force in vivo. However, this prior work has not focused on the requirements for scale-up to industrial processes. This dissertation reports on titanium surface modifications by electrochemical anodization using a benign NH₄F electrolyte, and a hybrid electrolyte also containing AgF, rather than hazardous hydrofluoric acid used elsewhere. Nanotube fabrication of Ti6Al4V foils, rods, thermal plasma sprayed commercial implants, and laser and e-beam melted powder materials was demonstrated.

It was found …

Degradation Resistant Surface Enhanced Raman Spectroscopy Substrates, Ryan D. Scherzer

UNF Graduate Theses and Dissertations

Raman spectroscopy is employed by NASA, and many others, to detect trace amounts of substances. Unfortunately, the Raman signal is generally too weak to detect when very small, but non-trivial, amounts of molecules are present. One way around this weak signal is to use surface enhanced Raman spectroscopy (SERS).

When used as substrates for SERS, metallic nanorods grown using physical vapor deposition (PVD) provide a large enhancement factor to the Raman signal, as much as 10¹². However, Silver (Ag) nanorods that give high enhancement suffer from rapid degradation as a function of time and exposure to harsh environment. …