Physical Sciences and Mathematics Commons^™

Synthesis, Molecular Characteristics, And Antibacterial Assessment Of Marine Hydroid Aqueous Extract-Based Silver Bio-Nanoparticles, Fredryk Mandey, Aulia Rhamdani Arfan, Rugaiyah Andi Arfah

Makara Journal of Science

This investigation aims to synthesize, analyze the molecularity, and test the ability of bacterial inhibition capability of silver nanoparticles that have been synthesized by simply mixing silver nitrate and aqueous extracts of marine natural products with and without the addition of amylum as a stabilizing agent. This research, with and without the addition of amylum as a stabilizing agent, obtained 39.0 and 55.2 mg of solids of round-shaped morphology silver nanoparticles with diameters of 87.9 and 103.0 nm., respectively. In addition, the antibacterial testing assay against Staphylococcus aureus and Escherichia coli showed some considerably good results. S. aureus with the …

New Ways To Improve Dispersibility Of Nanotubes: Approaching From The Formation Of Silicon Nanoparticles By High Energy Reactive Ball Milling (Herbm) In Polar Solvents, Julie P. Vanegas, Yolanda V. Gutierrez, Joaquin Rivera, Juan García Jr.

Research Symposium

Background: This research aims to synthesize stable silicon nanoparticles using different molar ratios of N-Cyclohexyl-2-pyrrolidone (CHP) and Silicon to demonstrate if there is any significance towards the production of effective nanotubes. To determine this, the synthesized nanoparticles will be characterized by scanning electron microscopy (SEM), UV visible absorption spectroscopy, and photoluminescence spectroscopy (PL).

Methods: 50 Mg of silicon wafer are added with differing ratios of ligand (CHP), 5mL of water, and 3 steel iron balls into a ball milling vial. Vials are then placed into a ball milling apparatus for 7 cycles or 3.5 hours. Once the cycles are complete, …

Scalable Solution Processing Of Niox Nanoparticles., Peter James Armstrong

Electronic Theses and Dissertations

Perovskite solar cells (PSCs) are a promising alternative to silicon-based photovoltaics. However, PSCs face several challenges due to shortcomings in their stability, module efficiency, and scaled production. Although PSCs is still a young field of research, significant attention has been given to demonstrating power conversion efficiencies that are on par with traditional silicon. With that target reached, converting the laboratory demonstration into practical materials to increase access and abundance of solar energy are among the next large targets for the field. This comes with material challenges for perovskite and their companion charge transport layers (CTLs). Among the charge transport materials …

Fabrication Of Gold Nanoraspberry Arrays By Soft Lithography, Christy Yu-Qing Xie

Undergraduate Student Research Internships Conference

Nanostructures and nanoparticles have garnered increasing interest over the past decade due to their unique properties and applications. These properties include localized surface plasmon resonance (LSPR) and allow for surface modification. We can tune these properties depending on the nanoparticle’s size, shape, and geometry.

This work aims to fabricate plasmonic platforms through patterning gold nanoparticles (raspberries) by microcontact printing, a simple and cost-effective soft lithography technique. This is done through large-scale patterning using polydimethylsiloxane (PDMS) stamps to pattern an adhesion template and spatially guide the adsorption of gold nanoparticles (AuNPs).

Sol-Gel Synthesis And Spectroscopic Characterization Of Titanium Dioxide Doped With Copper And Iron, Erin L. Jacoski

Chemistry Senior Theses

A source of bioavailable iron in open oceans stems from aerosols, increasing phytoplankton growth and the sequestration of atmospheric carbon dioxide. These aerosols contain semiconductors, like titanium dioxide, which is known to increase the bioavailability and can trigger photoreduction of Fe3+. Recently, it is suspected that other metals in the aerosols also influence the release of iron. In this work, the effects of doping with iron and copper on the physical characteristics of titanium dioxide nanoparticles, since the photocatalytic potential of titanium dioxide depends on its structure and metal content (anatase vs. rutile), were explored. Titanium dioxide nanoparticles were prepared …

Towards Semiconductor Nanorods With Nickel/Iron Cocatalyst., Kehinde Ayorinde

Masters Theses & Specialist Projects

The adverse effects associated with the utilization of fossil fuels has led to the need to provide an alternative cleaner energy. Photocatalytic hydrogen evolution reaction via water splitting provides a renewable pathway to generating energy. Our photocatalyst system includes a semiconductor component (CdSe/CdS core/shell nanorods) to capture light and an attached metal (cocatalyst) for the hydrogen evolution reaction. Platinum is an effective metal catalyst for this reaction due to strong proton binding energy that easily facilitates the reduction of water to produce hydrogen gas. However, due to the high cost of platinum, there is a need to find a less …

Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri

Doctoral Dissertations

High-entropy materials (HEMs) have emerged as a new class of multi-principal-element materials with great technological prospects. As a unique class of concentrated solid-solution materials, HEMs, formed on the premise of incorporating five or more principal elements into a single crystalline phase, provide an excellent opportunity to access superior catalytic materials ‘hiding’ in the unexplored central regions of a multicomponent phase space of higher orders.

However, the fabrication of HEMs is energy-intensive, typically requiring extreme temperatures and/or pressures under which agglomeration of particles occurs with a commensurate decrease in surface area. For most catalytic applications, non-agglomerated particles with high surface areas …

Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk

Dissertations, Theses, and Capstone Projects

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism …

Development Of Biomaterials For Drug Delivery, Raquel De Castro

Graduate Theses and Dissertations

Drug delivery systems (DDS) have highly evolved in the last decades with the development of hydrogels and nanoparticles. However, high systemic uptake, side effects, low bioavailability, and encapsulation efficiency continue to be a major hurdle faced by such DDSs.

Nanoparticles and hydrogels can be specifically designed for targeted DDSs to mitigate some of the problems. This dissertation aimed to design two DDSs for ocular drug delivery and one for cancer treatment. The first project sought to develop chitosan nanoparticles (Cs-NP) using PEGDA as a copolymer to encapsulate gentamicin (GtS) for ocular drug delivery. Cs-NPs contain positive charges that can interact …

Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal, Jazlynn Sikes

Graduate Theses and Dissertations

Nanomaterials have revolutionized science and technology. Their unique properties can be exploited, and nanoparticles are being used as catalysts, antimicrobials, drug delivery vehicles, sensors, and more. However, the fundamental properties of nanomaterials and their interactions with their surrounding environments are still poorly understood. In this work, a single-particle approach was used to observe the effects of capping ligand, surrounding solution, and particle shape on the oxidative process to gain deeper understanding of silver nanoparticle properties. When allowed the opportunity, the particles will adsorb to the electrode surface then oxidize in rapid succession upon electrode activation, regardless of capping ligand as …

Carrier-Free Chemo-Ptt/Pdt Ionic Nanomaterials For Combination Cancer Therapy, Samantha Macchi

Arkansas Women in STEM Conference

Herein, we describe a carrier-free combination nanodrug for treatment of cancer. In this work, we combined a photothermal compound and a chemotherapeutic drug using ionic liquid chemistry. We utilized a facile, one-step metathesis approach to replace the counter cation of a near infra-red (NIR) dye (photothermal agent) with a chemotherapeutic cation to synthesize an ionic material-based combination cancer therapy drug to deliver multiple mechanisms simultaneously. The nanodrugs were developed by using a reprecipitation method. The detailed photophysical properties of this new combination therapy molecule was investigated in ethanol solution as well as in nanoparticles forms in aqueous media. The singlet …

Fabrication Of Metal-Silicon Nanostructures By Reactive Laser Ablation In Liquid, Eric J. Broadhead

Theses and Dissertations

Metal-silicon nanostructures are a growing area of research due to their applications in multiple fields such as biosensing and catalysis. In addition, silicon can provide strong support effects to metal nanoparticles while being more cost effective than traditionally used supports, like titania. Traditional wet-chemical methods are capable of synthesizing metal-silicon nanostructures with a variety of composition and nanoparticle shapes, but they often require high temperatures, toxic solvents, strong reducing agents, or need capping agents added to stabilize the nanoparticles. Laser processing is an emerging technique capable of synthesizing metal-silicon composite surfaces that offers a faster, simpler, and greener synthesis route …

Investigating The Accumulation, Sub-Organ Distribution, And Biochemical Effects Of Nanomaterials Using Mass Spectrometry, Kristen Nicole Sikora

Doctoral Dissertations

Gold nanoparticles (AuNPs) are attractive materials for use in various biomedical applications, such as therapeutic delivery, due to their unique chemical properties and modular tunability. Mass spectrometry methods, including laser desorption/ionization mass spectrometry (LDI-MS) and inductively coupled plasma mass spectrometry (ICP-MS) have been successfully used to evaluate the distribution of AuNPs in complex biological systems. As new AuNP-based materials are developed for applications in therapeutic delivery, it is essential to simultaneously develop analytical techniques that can comprehensively assess their behavior in vivo. In this dissertation, novel mass spectrometric methods have been developed and utilized to evaluate the uptake, distribution, …

Low-Load Metal-Assisted Catalytic Etching Produces Scalable Porosity In Si Powders, Konstantin Tamarov, Riku Kiviluoto, Josph D. Swanson, Bret A. Unger, Alexis T. Ernst, Mark Aindow, Joakim Riikonen, Vesa-Pekka Lehto, Kurt W. Kolasinski

Chemistry Faculty Publications

The recently discovered low-load metal-assisted catalytic etching (LL-MACE) creates nanostructured Si with controllable and variable characteristics that distinguish this technique from the conventional high-load variant. LL-MACE employs 150 times less metal catalyst and produces porous Si instead of Si nanowires. In this work, we demonstrate that some of the features of LL-MACE cannot be explained by the present understanding of MACE. With mechanistic insight derived from extensive experimentation, it is demonstrated that (1) the method allows the use of not only Ag, Pd, Pt, and Au as metal catalysts but also Cu and (2) judicious combinations of process parameters such …

Chemical Manipulation Of Macrophages: Nanomaterial And Molecular Approaches, Joseph Hardie

Doctoral Dissertations

Macrophages, phagocytic cells of the innate immune system, are the body’s first line of defense against pathogens and are responsible for tissue maintenance. Macrophages are capable of sensing and internalizing external stimuli, and in response change their morphology and phenotype accordingly. Because macrophages are integral to immune function and tissue maintenance, dysregulation of macrophage behavior is associated with a range of diseases including infections, cancer, autoimmune disorders, atherosclerosis, and more. Because of the implications of macrophage failure, there is interest in creating new materials to manipulate macrophage behavior for a therapeutic effect. In this thesis, I describe the application of …

Enhancing Upconversion Nanoparticle Performance Of Nayf4: Yb,Tm With Doping Optimization And Shell Addition And Of Nayf4: Yb,Er With Yb,Nd Shell Addition, Ashleigh M. Chov

Honors Thesis

Upconversion (UC), is a phenomenon that occurs when low-energy excitation (usually near-infrared (NIR)) results in higher-energy emission. Upconversion nanoparticles (UCNPs) are particles less than 100 nm in size that are synthesized using rare earth metals such as Yb, Er, Tm, and Y. UCNPs have important applications in a variety of fields, including bio-imaging, security printing, and latent fingerprint development. Traditional methods for latent fingerprint development such as fluorescent powder dusting have several drawbacks including low contrast, high background interference, and autofluorescence. NIR-to-NIR UCNPs are composed of NaYF₄: Yb, Tm and emit 800 nm light under 980 nm excitation …

Powering Advances In Next-Generation Photovoltaics Through Materials Synthesis And Characterization, Christie L.C. Ellis

Doctoral Dissertations

Solar energy is our most abundant natural resource: the energy from sunlight that strikes the Earth in one hour is more than the energy consumed globally in a year. This makes photovoltaics, which convert solar energy into electrical energy, a critical technology to pursue. 95% of the photovoltaic market is dominated by silicon; its high efficiency, stability, and plummeting manufacturing costs made it the clear choice for commercialization. However, silicon solar cells are thick, heavy, opaque, and rigid, limiting potential applications. They are energy- and resource-intensive to produce, and their manufacturing process uses and produces several toxic substances. “Next-generation” photovoltaic …

Preparation Of Folic Acid-Carbon Dots-Doxorubicin Nanoparticles As Targeting Tumor Theranostics, Samson Dada

Electronic Theses and Dissertations

Carbon dots (CDs) have attracted much attention as an excellent gene/drug delivery and biological imaging agent for early cancer theranostics. In this study, we prepared two series of nanoparticles (NPs), which are composed of (CDs) with a targeting agent, folic acid (FA), and a chemotherapeutic agent Doxorubicin (Dox). All the NPs and their intermediates were characterized using ultraviolet-visible spectroscopy (UV-vis), fluorescence spectroscopy, and Fourier transform-infrared spectroscopy (FT-IR). The drug loading capacity (DLC) and drug loading efficiency (DLE) of two series of FA-CDs-Dox were assessed using UV-vis absorption spectroscopy at the wavelength of 485 nm. Both showed good DLE and DLC …

Zinc–Phosphorus Clusters For Solution Synthesis Of Zinc Phosphide Nanoparticles, Kyungseop Lee

Electronic Thesis and Dissertation Repository

Synthesis of zinc phosphide (Zn₃P₂) nanoparticles is an emerging topic of investigation as Zn₃P₂ is a candidate material for the next generation solar cells. Despite the early discovery of its favorable electronic properties that are well-suited for photovoltaic applications, a major focus of synthetic strategy was with vapor/chemical deposition methods. Solution methods with greater control over size, crystal structure and composition at a lower production cost, has been underdeveloped in comparison. In this context, this thesis describes the synthesis, characterization and reactivity of zinc phosphido clusters: [Zn₂(μ-PPh₂)₂(PPh …

Synthesis And Characterization Of Multifunctional Transition Metal Oxide Nanoparticles Through A Modified Sol-Gel Method With Application In Energy Storage, Julien Lombardi

Dissertations, Theses, and Capstone Projects

The Synthesis of transition metal oxide nanoparticles has been studied in great detail over the many years. The most studied transition metal oxide nanoparticles are perovskites of the ABO₃ stoichiometry (A and B = transition metal) and more recently double perovskite crystal structures of the AA’BO₆ or A₂BB’O₆ stoichiometry due to the many different properties arising from the many different combinations of elements possible. These materials have proven potentially useful in many fields, but due to properties such as ferroelectricity and ferromagnetism, the desire to integrate these materials into electronics is ever growing. Many synthesis …

Deposition Of Platinum Particles On Surface-Modified Carbon Ultramicroelectrodes, Caitlin Millsaps

Undergraduate Honors Theses

Nanoparticles are used as electrocatalysts due to their large surface area-to-volume ratios. Most studies of nanoparticle electrocatalysis are performed on collections of particles on a support, which represent ensemble average behavior influenced by spatial distribution of the nanoparticles. Therefore, recent emphasis has been placed on analyzing electrocatalytic behavior of single particles. The focus here is to develop carbon ultramicro- and nanoelectrode platforms for studying the electrocatalytic properties of single metal nanoparticles. Ultramicroelectrodes were prepared using chemical vapor deposition of carbon in pulled quartz capillaries. Electrode diameters were determined by cyclic voltammetry. Electrodes were modified using a soft nitriding technique to …

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 …

The Investigation Of Photocatalytic And Adsorptive Properties Of Humic Acid Grafted Magnetite Nanoparticles For The Remediation Of Arsenic, Selenium And Phosphorous From Water, Mohammad Mamunur Rashid

FIU Electronic Theses and Dissertations

The crisis of freshwater has been a big concern worldwide. Water contamination that occurs through the discharge of toxic pollutants from different natural and anthropogenic sources have worsened the situation. Adsorption has emerged as a simple and economical water treatment procedure although the challenge is to find the right adsorbent that can efficiently remove the target contaminant followed by their easy recovery from the reaction vessel. In this dissertation, I have focused on the synthesis, characterizations and applications of environmentally compatible and magnetic humic acid coated magnetite nanoparticles (HA-MNP) as a potential adsorbent for water purification.

Phosphate is an essential …

Imidazolium Ionic Liquids As Multifunctional Solvents, Ligands, And Reducing Agents For Noble Metal Deposition Onto Well-Defined Heterostructures And The Effect Of Synthetic History On Catalytic Performance, Michael Drake Ballentine

Masters Theses & Specialist Projects

1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]Tf2N) was investigated as a multifunctional solvent, ligand, and reducing agent for platinum deposition onto well-defined CdSe@CdS nanorods. Platinum deposition was carried out thermally and photochemically using Pt(acac)2 as the metal precursor. Thermal deposition was investigated in [BMIM]Tf2N with and without addition of a sacrificial reducing agent, and product topology was compared with the products obtained from polyol reduction using 1,2-hexadecanediol, oleic acid, and oleylamine in diphenyl ether. Photochemically induced platinum deposition was carried out at room temperature in [BMIM]Tf2N, and product topology was compared with the photodeposition products obtained from a toluene dispersion. Thermal deposition of platinum …

Systematic Size Control In The Synthesis Of Zero-Valent Iron Nanoparticles, Grant C. Bleier

Chemistry and Chemical Biology ETDs

A novel synthetic method for the production of highly magnetic, low size-dispersity nanoparticles through reversible magnetic agglomeration is introduced and studied in detail. Initially, a weakly coordinating surfactant (3-octadecyl-2,4-pentanedione) is employed to produce a wide range of nanoparticle sizes ranging from 8 to 20 nm in diameter. The kinetics faced in these reactions by cheap and widely available iron complex precursors can be avoided in this method with the introduction of thermodynamic control, which occurs in the form of a magnetic precipitation event that essentially halts nanoparticle growth. Utilizing this synthetic method, the length of the alkyl chain on the …

Synthesis And Characterization Of Magnetic Cabides And Oxides Nanomaterials, Hei Man Tsui

Theses and Dissertations

The design and development of nanoparticles is of great interest in the current energy and electronic industry. However, based on the current materials available the production cost can be high with insignificant magnetic and mechanical properties. Specifically, rare-earth magnetic materials composed of neodymium and samarium are known for their high magnetic performance, however, due to the cost of development there is a need to develop a versatile and cost effective material. Alternatively, cobalt carbide nanomaterials have shown to be a promising alternative for rare-earth free magnets as they exhibit comparable properties as hexaferrite magnetic materials. The primary goal of this …

Water-Soluble Pd And Pd-Alloy Nanoparticles As Catalysts In Biphasic Solvent., Shekhar Bhama

Electronic Theses and Dissertations

This dissertation shows the chemical synthesis of Pd and Pd-alloy nanoparticles (NPs) and their hydrogen and thermal stabilities for applications in the homogeneous and pseudo-homogeneous catalysis of organic reactions. Mainly, this dissertation describes 1) the chemical synthesis of Pd, PdPt, PdAu and Cu-Pd core-shell NPs coated with various organic ligands (thiols, amines and citrate), with different metal compositions in different synthetic environment, 2) the stability of solutions containing various NPs in the presence of hydrogen or varying temperatures, 3) the evaluation of the catalytic activity of Pd, PdPt, PdAu and CuPd NPs for hydrogenation/isomerization of allylic alcohols, and 4) the …

Real Time Monitoring Of Photocatalysis: An Application And Expansion Of The Quartz Crystal Microbalance, Perrin Godbold

Senior Honors Projects, 2010-2019

There are many applications of photocatalytic chemistry, with hundreds of researchers investigating photocatalytic materials. Another method of investigation could aid these researchers and contribute significantly to this field. This study attempts to develop a new method of analysis by expanding the capabilities of the Quartz Crystal Microbalance (QCM) into the realm of photocatalysis. We coated QCM crystals with the stable and well-known photocatalyst, titanium dioxide, and utilized these coated crystals to begin to develop an analysis procedure for our modified instrument. Some indication of the QCM’s sensitivity was seen, but the UV irradiation elicited a frequency change independent of the …

Controlled Synthesis And Utilization Of Metal And Oxide Hybrid Nanoparticles, Cameron Cowgur Crane

Graduate Theses and Dissertations

This dissertation reports the development of synthetic methods concerning rationally-designed, hybrid, and multifunctional nanomaterials. These methods are based on a wet chemical, solution phase approach that utilizes the knowledge of synthetic organic and inorganic chemistry to generate building blocks in solution for the growth of nanocrystals and hybrid nanostructures. This work builds on the prior knowledge of shape-controlled synthesis of noble metal nanocrystals and expands into the challenging realm of the more reactive first row transition metals. Specifically, a microemulsion sol-gel method was developed to synthesize Au-SiO2 dimers as precursors for the synthesis of segmented heterostructures of noble metals that …

Design Of 3d Macroporous Inverse Opal Tio2 Binary And Ternary Composites Sensitized With Gold Nanoparticles And Cds Quantum Dots For Photocatalysis, Daniel A. Corella

Master of Science in Chemical Sciences Theses

Materials composed of titanium (IV) oxide (TiO₂) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports …