Physical Sciences and Mathematics Commons^™

Manufacturing Of A Flexible Piezoelectric Nanogenerator By Functionalizing Polyvinylidene Fluoride With Lithium Tantalate And Multiwalled Carbon Nanotubes For Energy Harvesting And Sensing Applications, Islam Uddin Shipu

Theses and Dissertations

Mechanical energy is one of the readily accessible green energy sources that could be employed to meet the small-scale energy requirement. In order to capture mechanical energy, power the next generation of electronic gadgets, and health monitoring flexible piezoelectric nanogenerators made of light weight polymers and carbon nanotubes have drawn a lot of attention. Lithium tantalate (LiTaO3), a ferroelectric substance, was prepared here and utilized to create a flexible piezoelectric nanogenerator (FPNG). A compact piezoelectric nanogenerator that successfully transfers mechanical energy into electricity was then created using lightweight polyvinylidene fluoride (PVDF), multi-walled carbon nanotube (MWCNT), and LiTaO3 nanoparticles. To create …

Expanding The Scope Of Clickable Azide-Functionalized Nanoclusters To Include Au144, Johanna A. De Jong

Electronic Thesis and Dissertation Repository

Thiolate-protected Au₁₄₄ nanoclusters (NCs) are an intriguing member of the gold NC family. Their geometric structure, distinct electrochemical features, and susceptibility to structural rearrangement under the duress of ligand exchange have been studied. However, there are currently no established protocols for surface modification or tuning of their ligand shells post synthesis. Here, the direct synthesis of three regioisomers of azide-modified Au₁₄₄ NCs with 60 azide moieties, i.e., Au₁₄₄(SC₂H₄C₆H₄-N₃)₆₀, is reported, in which the azide functionality is located at the ortho-, meta-, or …

Tailored Nanomaterials For Advancing Fast-Charge Research, Wessel Van Den Bergh

Theses and Dissertations

The demand for fast, energy-dense storage has driven research into nanoscale intercalation materials. Nanoscale materials not only accelerate kinetics but also can modify reaction path thermodynamics, intercalant solubility, and diffusivity. Pioneering works have revealed such nanoscale changes, often without the need to separately probe each fundamental transport process. While electrodes can be designed to have one transport processes dominant, there remain opportunities to better understand energy-dense designs with multiple concomitant transport constraints. The contents herein highlight emerging an method using tailored, energy-dense nanomaterials and the process of elimination to clearly correlate architectural features to performance. For example, this method revealed …

Optimizing The Fluorescent Quantum Yield Of Carbon Dots, Megan B. Prado

MSU Graduate Theses

Carbon dots (CDs) are a subclass of carbon nanomaterials that exhibit unique properties of fluorescence, photostability, low toxicity, and biocompatibility. These unique properties have enabled numerous applications including biosensing, heavy-metal detection, and pH-sensing, among others. Their optical properties can be modified via doping to produce increasingly fluorescent CDs after appropriate purification. Herein, doped CDs were synthesized in four bottom-up methods for comparison using sucrose or citric acid as carbon precursors. Varying hetero-atom dopants (N, S, B) were used in differing molar ratios. The pH-dependent fluorescence and fluorescent quantum yield (QY) were measured for each sample. Characterization was conducted using Fourier-Transform …

Rational Design Of Multifunctional Nanocatalysts For Environmental Remediation And Energy Conversion Technologies, Md Ariful Ahsan

Open Access Theses & Dissertations

The discovery of efficient and sustainable carbon-based nanotechnologies to solve both the scarcity of drinking water and global energy crisis has become a paramount task in the last decades. Owed to the fast population growth and industrialization of the modern society, access to potable water and clean energy technologies is becoming very hard around the globe. Water pollutants have become a serious threat to the environment and ecology because of their toxic nature. Parallelly, the current hydrocarbon-based fuel industries are generating high levels of contamination across the planet, making imperative the development of cleaner energy technologies. In this regard, the …

Design, Synthesis, And Catalytic Application Of Crystalline Porous Nanomaterials, Zainab Abdullah Almansaf

Graduate Theses and Dissertations

Chapter 1: COFs (covalent organic frameworks) are a new type of microporous crystalline polymer connected by organic units via strong covalent bonds. Due to their well-defined crystalline structures and excellent chemical and thermal stabilities, COF materials are considered promising candidates in applications such as gas adsorption, catalysis, and energy storage.Chapter 2: A new covalent organic framework (COF) based on imine bonds was assembled from 2-(4-formylphenyl)-5-formylpyridine and 1,3,6,8-tetrakis(4-aminophenyl)pyrene, which showed an interesting dual-pore structure with high crystallinity. Postmetallation of the COF with Pt occurred selectively at the N donor (imine and pyridyl) in the larger pores. The metalated COF served as …

Chitosan Graphene Composite Fabrication And Characterization For Treatment Of Harmful Algal Blooms And Toxins, Sarah Zetterholm

Master's Theses

Chitosan graphene composites were fabricated and characterized as a management strategy for harmful algal blooms (HABs) caused by various species of cyanobacteria. These chitosan graphene materials were compared to previously studied chitosan graphene-oxide composites in both material properties and HAB treatment. In previous studies, adsorption of the cyanobacteria onto the surface of the composite materials has been observed. Investigations of the pure materials for these composites are also included in this study to determine whether removal is a result of charge interactions with the composite, or as an inherent property of the graphene or graphene oxide. Initial results suggest that …

Investigations On The Surface Chemistry Of Colloidal Quantum Dots Towards Fluorescent Biological Probes, John Hardin Dunlap

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) have garnered significant interest as promising materials for biological applications due to their improved photostability and narrow, tunable photoluminescence properties compared to organic fluorophores. To facilitate their utility as fluorescent bioimaging probes, QDs must undergo post-synthetic modifications to exchange their native hydrophobic ligands from synthesis with hydrophilic ones that enable colloidal dispersions in aqueous environments. Many examples exist that demonstrate surface modifications for water-soluble QDs and their efficacy in biological systems, however, there is a need to develop a more thorough understanding of how hydrophilic ligands coordinate to QD surfaces in order to develop more …

Design And Development Of 2d Functional Semiconductor Nanocrystals, Andrew Hunter Davis

Dissertations - ALL

Anisotropic nanocrystals (NCs) have become of keen interest in recent years, especially for applications in optoelectronic devices due to their directionally oriented emissions, narrow emission spectra, and suitable morphologies for device integration. Of the desired anisotropic NCs, two-dimensional (2D) NCs are of profound interest, due to their impressive optical and electronic properties as well as their prospective advantages towards applications in layered optoelectronic devices, such as solar cells. However, 2D NCs face many challenges, including limited synthetic derivation, as well as decreased stability and optical response, due to their large surface-to-volume ratio and reactive planar surface increasing surface defect state …

Nanoorthogonal Surface Modifications Of Gold Nanoparticles And Nanoclusters Through Strain-Promoted Cycloaddition Chemistry, Praveen N. Gunawardene

Electronic Thesis and Dissertation Repository

This thesis explores the preparation of thiolated gold nanoparticles (AuNPs) and thiolated gold nanoclusters (AuNCs) capable of undergoing post-assembly surface modifications using two common “bioorthogonal” click reactions: the strain-promoted alkyne-azide cycloaddition (SPAAC) reaction (which occurs between a strained-alkyne and an azide) and the strain-promoted alkyne-nitrone cycloaddition (SPANC) reaction (which occurs between a strained-alkyne and a nitrone). Due to their rapid and modifiable reaction kinetics, high chemoselectivity, and stability of the reactive partners, these reactions were originally designed to tether functional substrates to biologically sensitive biomolecules, without altering their structure or perturb the biologically sensitive environments in which they …

Plasmonic Metallic And Semiconductor Nanomaterials, Mengqi Sun

Theses and Dissertations

The earliest account of localized surface plasmon resonance (LSPR) has to date back to the ancient age of Rome in 400 A.D. The famous glass of Lycurgus cup told the story of unique light-and-matter interaction at the nanoscale that confines the electromagnetic field resonance at its surface and therefore allows LSPR feature to noticeably arise. The conventional metallic LSPR nanomaterials, like Au and Ag nanoparticles attract constant attentions due to their synthetic simplicity, chemical robustness, and visible spectral response. Its ability to generate sensitive dielectric sensing of the surroundings, strong electromagnetic field and active charge carriers upon optical excitation triggered …

Light-Directed Growth Of Semiconductor Nanomaterials By Photoelectrodeposition, Chu Qin

Arts & Sciences Electronic Theses and Dissertations

In this work, the chemical and physical properties of semiconductor microcrystals and metastable polymorphs were transformed through photoexcitation during electrochemical synthesis. Interfacial charge transfer using photogenerated carriers were used to successfully control the growth of metal oxide semiconductors and change their morphology, composition improve their catalytic activity. The main material systems studied in this thesis are electrodeposited copper oxide (Cu2O) and manganese oxide (MnOx) semiconductor films. Illumination can direct the shape transformation of Cu2O crystals at the nanoscale by facet-selective charge transfer. During photoelectrodeposition on Cu2O microcrystals with well-developed facets, light mediates the deposition of copper metal selectively on the …

The Rational Synthesis Of Lanthanum Manganite Nanomaterials For Magnetic Refrigeration Applications, Caitlin Hunt

Theses and Dissertations

Refrigeration systems for the cooling of commercial and residential buildings are a major drain on energy resources and source of greenhouse gas emissions. Magnetic refrigeration, which employs the magnetocaloric effect, has the potential to mitigate the energy drain and greenhouse gas emissions for air conditioning. In order to commercialize magnetic refrigerators, a material with a high magnetic entropy change, ΔS, near room temperature which is simple and inexpensive to create is needed.¹ Current options for this solid refrigerant are either expensive, difficult to synthesize, or have a ΔS or T_c (the Curie Temperature, where ΔS is maximized) below …

Cytoviva Hyperspectral Imaging For Comparing The Uptake And Transformation Of Agnps And Ag+ In Mitochondria, Kristina Steingass

Browse all Theses and Dissertations

Nanomaterials have attracted significant attention in the last decade, with applications in everyday products. Amongst all known nanomaterials in use, silver is the leading metal, present in 531 different types of products, owing to their unique optical, electrical, antimicrobial, and thermal properties. Though silver nanoparticles (AgNPs) come in contact regularly with the general population, there is little known about their toxicity mechanism due to limited techniques for thorough analysis. CytoViva Hyperspectral Imaging (HSI) shows potential for filling these gaps. In this study, borohydride-capped AgNPs with an approximate diameter of 10 nm were synthesized using the modified Creighton method and characterized …

Pressure Driven Desalination Utilizing Nanomaterials, Fangyou Xie

Master's Theses

Nanomaterials such as graphene oxide and carbon nanotubes, have demonstrated excellent properties for membrane desalination, including decrease of maintenance, increase of flux rate, simple solution casting, and impressive chemical inertness. Here, two projects are studied to investigate nanocarbon based membrane desalination. The first project is to prepare hybrid membranes with amyloid fibrils intercalated with graphene oxide sheets. The addition of protein amyloid fibrils expands the interlayer spacing between graphene oxide nanosheets and introduces additional functional groups in the diffusion pathways, resulting in increase of flux rate and rejection rate for the organic dyes. Amyloid fibrils also provide structural assistance to …

Peo-Ppo-Peo Surfactant Mixtures As Templates For Silicas With Very Large Cylindrical Mesopores At Ambient Temperature And With Helical Mesopores At Sub-Ambient Temperature, Laurance Beaton

Dissertations, Theses, and Capstone Projects

The original research described herein concerns the synthesis of mesoporous silicas through a surfactant-templating method. The approach taken involved the use of a mixed surfactant system of two poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactants, with one of the copolymers containing a much larger percentage of hydrophobic (PPO) blocks than the employed co-surfactant. Systematic adjustments of experimental parameters initially enabled the preparation of 2-D hexagonally ordered mesoporous silicas (SBA-15) of uncommonly large pore diameter at ambient temperature. Comparable silica was synthesized with and without temperature control. Additional adjustments to experimental parameters, including reduction of the relative amount of framework precursor used in …

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

Spectroscopic Investigations Of Excited Charge Carriers In Ii-Vi Nanoparticles, William Matthew Sanderson

Arts & Sciences Electronic Theses and Dissertations

The large absorption cross sections and the tunability of the energetic spacings between the states in the conduction (CB) and valence band (VB) within a semiconductor nanoparticle (NP) make them promising media for capturing electromagnetic radiation and converting it into charge carriers, or electricity. In photovoltaic devices that incorporate semiconductor NPs, it would be ideal if every photon could be absorbed by a NP and the carriers could be collected with perfect efficiency and without loss of energy. The relaxation pathways of the carriers within the NPs down to the band edge and their fate at the band edge contribute …

Laser Ablation In Liquid For The Controlled Production Of Photoluminescent Graphene Quantum Dots And Upconverting Nanoparticles, Rosemary Lynn Calabro

Theses and Dissertations--Chemistry

Photoluminescent­ (PL) nanomaterials play an important role in areas including displays, sensing, solar, photocatalysis, and bio applications. Traditional methods to prepare PL materials suffer many drawbacks such as harsh chemical precursors, complicated synthetic steps, and production of many byproducts. Laser ablation in liquid (LAL) has emerged as a promising alternative to prepare materials that is single-step, fast, uses fewer precursors, produces fewer side products, and has simple purification steps. During LAL, a solid target is irradiated with a pulsed laser source. The laser pulses cause plasma plumes of the target material to form which are cooled, condensed, and can react …

Ultrafast And Real-Time Dynamics Of Nanomaterials Studied By Advanced Spectroscopic Techniques, Jeewan Chaminda Ranasinghe

LSU Doctoral Dissertations

Ultrafast and nonlinear spectroscopies are used to study excited-state dynamics and monitor real-time growth dynamics of different types of nanomaterials. In the first study, the growth dynamics of colloidal gold-silver core-shell nanoparticles are studied using in situ second harmonic generation and extinction spectroscopy. The growth lifetimes are studied under different reaction conditions, resulting in different silver shell thicknesses, with spectral comparisons to finite-difference time-domain calculations. The results are consistent with a three-step growth process. During the first step of the nanoparticle growth reaction, rough and uneven surfaces are formed rapidly giving rise to plasmonic hot spots with corresponding broad, red-shifted …

Modification Of 2d Materials Utilizing Functional Polymer Interfacial Layers, Ryan Selhorst

Doctoral Dissertations

This dissertation describes the modification of 2D transition metal dichalcogenides (TMDCs). These materials exhibit unique electronic properties, ranging from metallic to insulating, and can transport either electrons (n-type) or holes (p-type). Polymers containing electronically-active moieties offer a path to control the electronic properties of a 2D material without altering the inherent structure of the semiconductor. This dissertation focuses on the synthesis of polymers bearing chalcogen-rich or zwitterionic moieties to alter the electronic and solution properties of 2D materials. Chapter 2 describes polymers containing sulfur-rich tetrathiafulvalene (TTF) and their effects as electroactive coatings on the TMDC molybdenum disulfide (MoS₂). …

Development Of Bioorthogonal Molecular Tools On Gold Nanoparticles, Wilson Luo

Electronic Thesis and Dissertation Repository

This thesis describes the development of bioorthogonal chemical tools — originally designed to form bonds cleanly and selectively in living systems — on gold nanoparticles (AuNPs) as a model reactive nanomaterial template to showcase chemical modifications in a facile and robust manner. To achieve this goal, new methodologies to cleanly incorporate strained alkyne (SA) and cargo-bearing triarylphosphine derivatives onto AuNPs were developed. The protocols described herein provide well-defined reactive AuNP interfaces that undergo bioorthogonal bond-forming and breaking reactions cleanly, selectively, and rapidly to enable chemical tuning of their properties and function.

In order to circumvent the high reactivity of SAs, …

Synthesis, Stabilization, And Modification Of Zinc Oxide Nanoparticles For Biological Applications, Allison Kimberly Freese

MSU Graduate Theses

Nanoparticles have become very useful as delivery systems in biomedicine. The nanoparticles can be layered with different compounds to produce a vessel for transport of biological materials. Specifically, gold nanoparticles layered with a reducing agent, lysozyme, and polyelectrolytes can be synthesized to transport lysozyme into a cell. However, zinc oxide nanoparticles are cheaper, biocompatible nanoparticles that can be used for the same process. Here in, zinc oxide nanoparticle conjugates were synthesized, modified, and analyzed to be used as a biological material delivery system. The zinc oxide nanoparticles were synthesized using zinc chloride and sodium hydroxide. The particles were then layered …

Design Of Cotton Fabric-Based Binary And Ternary Composite Materials Containing Nanostructured Zno, Tio2, And Plasmonic Nanoparticles: Photocatalytic Applications, Latanya Downer

Master of Science in Chemical Sciences Theses

Nanostructure metals and metal oxides can be used for surface functionalization and combined with different materials to increase functionality. Recently, surface functionality has been of interest due to its multi-component and its ability to generate new material properties. One of its main application is the creation of nanomaterials because of its novel physical properties which contribute towards stabilization, strength, and catalytic properties. Nanomaterials makes it possible to fabricate objects in the nanoscale size range which offers beneficial physical properties. The nanomaterial distinctiveness allows for the creation of materials with unique characteristics for different applications such as photocatalytic coatings. Semiconductor and …

Binary And Ternary Transition Metal Pnictide Nanoparticles And Their Three-Dimensional Assemblies: Towards Promising Magnetic Refrigeration Materials, Malsha Anuradhi Hettiarachchi

Wayne State University Dissertations

BINARY AND TERNARY TRANSITION METAL PNICTIDES NANOPARTICLES AND THEIR THREE DIMENSIONAL ASSEMBLIES: TOWARDS PROMISING MAGNETIC REFRIGERATION MATERIALS

by

MALSHA ANURADHI HETTIARACHCHI

May 2019

Advisor: Dr. Stephanie L. Brock

Major : Chemistry

Degree : Doctor of Philosophy

Bulk MnAs has been recognized as a potential MR material with large MCE. However, the magnetic transition of bulk MnAs suffers from a large thermal hysteresis of 6 K precluding efficient MR cycling, and the magnetic entropy change associated with the phase transition is limited to a narrow temperature range, making the temperature control window very small. Solid solutions of MnAs, synthesized by both …

Nanomaterials For Double-Stranded Rna Delivery, Stuart Lichtenberg

Theses and Dissertations--Plant and Soil Sciences

RNA interference has enormous potential as a potent, specific, and environmentally friendly alternative to small molecule pesticides for crop protection. The use of exogenous double-stranded RNA offers flexibility in targeting and use in crops in which transgenic manipulation is not an option. The combination of RNAi with nanotechnology offers further advantages that are not available with dsRNA alone. In this work, I have evaluated several different combinations of nanomaterials and polymers for use in RNAi-based pest control systems. First, I have characterized the use of chitosan/dsRNA polyplex nanoparticles for gene knockdown using the model nematode Caenorhabditis elegans. Though chitosan/dsRNA …

Nanoscale Building Blocks: Bridging The Gap Between Potential And Realized Applications, Nicole Ritter

Theses and Dissertations (Comprehensive)

The vast potential of nanoparticles and nanotechnology remains largely untapped; the crucial bottleneck being the knowledge gap between making and using nanoparticles (NPs). This PhD work bridges this gap by focusing on synthesizing nanoparticles with applications at the forefront. Four peer-reviewed publications are presented in Chapters 3-6, a safety and toxicological perspective is given in Chapter 7, and current work and future progress are summarized in Appendix 1. Bimorphic silver nanoparticles were prepared, presenting an innovative method to synthesize diverse nanostructures using polymeric surface blocking to break symmetry in seeded regrowth (Chapter 3).¹ Silver stars with D_5h symmetry …

Nanomaterials Of Iron Oxide, Boron, And Boron Nitride: On The Path To Magnetic Guided Bioconjugates For Medical Applications, John Ryan Wozny

Graduate Research Theses & Dissertations

The functionalization of boron-based bioconjugates has long been studied for their potential use as a drug candidate for boron neutron capture therapy (BNCT). Also, magnetic nanoparticles have received greater attention due to their interesting magnetic properties and behaviors for selectively guiding them with an external magnetic field through the blood. A combination of the two ideas gives the framework for nanotechnology that has the potential to revolutionize drug delivery systems. This thesis will focus systematically on individual elements required for the many moving pieces required for magnetic drug targeting.

The research discussed in this thesis is divided into three parts. …

Influence Of Applied Potential And Metal Ion Concentraion On Metal Electrodeposition At Micron Gap Gold Electrodes, Krista Michel Riggins

Online Theses and Dissertations

Zamborini and Coworkers developed, a simple, low cost, and highly parallel electrochemical approach for fabricating nano-scale (metal/metal) or molecular (metal/polymer or self-assembled monolayer (SAM)/metal) junctions that should be useful in preparing working sensors and molecular electronic devices. The fabrication of metal/metal junctions involves metal deposition on one set of electrodes (E1), where the metal grows and becomes connected to a second set of electrodes (E2) of an Au interdigitated array of electrodes with a 5 µm separation. However, when different metals were deposited, they deposited in different fashions. Ag grew in the form of wires and Palladium deposited in the …

Temperature-Dependent Kinetic Studies Of Arsenicals Adsorption From Solution To Hematite Nanoparticles, Sara Soldoozy

Theses and Dissertations (Comprehensive)

Surface chemistry is the study of the chemical and physical phenomena that transpire at interfaces such as liquid-solid, solid-gas, liquid-gas, and liquid-liquid. To study the reactions occurred at the surfaces, surface sensitive techniques come to play. Adsorption of arsenical compounds (liquid adsorbate), particularly arsenate (iAs) and dimethylarsinic acid (DMA), to the surface of iron bearing materials (solid adsorbent) that frequently are found in geosorbents such as hematite (Fe₂O₃) has been studied in this thesis. Arsenical compounds can pollute the environment through natural sources and anthropogenic activities, and ultimately contaminate water. Absorbing these pollutants to a material …