Chemistry Commons^™

Elucidation Of The Toxicity Of Anthropogenic Nanoparticles In Environments Containing Heavy Metals, Chartanay Bonner

Dissertations

The design, synthesis, and applications of anthropogenic nanoparticles continue to rise as technologies utilizing the unique chemical and physical properties of materials with nanoscale dimensions emerge. Engineered silver nanoparticles (Ag NPs) possess antimicrobial properties toward several strains of antibiotic-resistant bacteria. The manufacturing and use of Ag NPs have led to their increased presence in the environment as pollutants. The interaction of Ag NPs with other pollutants influence their surface properties, aggregation state, stability and consequently, their toxic response toward microbial pathogens. In the present study, we examined the interaction of heavy metal ions (Cd²⁺, Hg²⁺, and …

Synthesis, Modification, Characterization And Processing Of Molded And Electrospun Thermoplastic Polymer Composites And Nanocomposites, Tamalia Julien

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on the versatility and integrity of a novel, ultrasoft polycarbonate polyurethane (PCPU) by the introduction of nanoparticles and lithium salts. Additionally, the research takes into account the use of electrospinning as a technique to create PCPU and polyimide (PI) fibers. These polymers are of interest as they offer a wide range of properties and uses within the medical and industrial fields.

An industrial batch of an ultrasoft thermoplastic polyurethane (TPU) was synthesized using a two-step process. The first was to create an end capped pre-polymer from methylene bis (4-cyclohexylisocyanate), and a polycarbonate polyol made up of 1,6- …

Robust Microplate-Based Methods For Culturing And In Vivo Phenotypic Screening Of Chlamydomonas Reinhardtii, Timothy C. Haire, Cody Bell, Kirstin Cutshaw, Brendan Swiger, Kurt Winkelmann, Andrew G. Palmer

Biomedical Engineering and Sciences Faculty Publications

Chlamydomonas reinhardtii (Cr), a unicellular alga, is routinely utilized to study photosynthetic biochemistry, ciliary motility, and cellular reproduction. Its minimal culture requirements, unicellular morphology, and ease of transformation have made it a popular model system. Despite its relatively slow doubling time, compared with many bacteria, it is an ideal eukaryotic system for microplate-based studies utilizing either, or both, absorbance as well as fluorescence assays. Such microplate assays are powerful tools for researchers in the areas of toxicology, pharmacology, chemical genetics, biotechnology, and more. However, while microplate-based assays are valuable tools for screening biological systems, these methodologies can significantly alter the …

Chemotherapeutic Applications Of Rhodamine Based Nanogumbos, Nimisha Bhattarai

LSU Doctoral Dissertations

The work presented in this dissertation employs nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) for selective chemotherapeutic applications. GUMBOS, similar to ionic liquids, are organic salts consisting of a bulky cationic and anionic moiety. In contrast to ionic liquids, these materials have melting points ranging from 25–250 °C, making them solid phase at room temperature. Similar to ionic liquids, GUMBOS display tunable properties, such as hydrophobicity and solubility, through counter ion variation. These tunable properties provide a variety of applications for these GUMBOS, including selective chemotherapeutics applications. The …

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 …

Removal Of Five Cationic Dyes Using A Resin Coated With Nickel/Nickel Boride Nanoparticles, Merve Çinar, Yasemi̇n İşlek Coşkun, Tüli̇n Deni̇z Çi̇ftçi̇

Turkish Journal of Chemistry

Resins coated with nickel/nickel boride nanoparticles were used to remove brilliant green, methyl violet, methylene blue, phenosafranine, and brilliant cresyl blue from water. The effects of pH, adsorbent dose, contact time, and initial dye concentration on the adsorption efficiencies were investigated. The point of zero charge for the adsorbent was pH 9.5. Isotherm studies were conducted using Langmuir, Freundlich, and Dubinin--Radushkevich models, and thermodynamic studies were also performed. Adsorption of the five dyes was found to obey the Langmuir isotherm model and was endothermic. The maximum adsorption capacities calculated from the Langmuir isotherm were 66.7, 88.5, 144.9, 56.2, and 147.1 …

Chemically And Biologically Responsive Nanoparticle Systems For Biomarker Detection And Combination Cancer Therapy, Neil M. Robertson

Legacy Theses & Dissertations (2009 - 2024)

The uniqueness and expression of miRNAs as biomarkers in certain cancers has the potential to radically alter the detection, and therefore the treatment, of the disease. Not only are current detection methods time consuming, and not sensitive enough for biomedical applications, but these small RNAs have yet to be fully utilized in treatment. By utilizing different nanomaterials we aimed to create novel nanodevices for the early, sensitive and specific detection of these biomarkers in a minimally invasive way and develop dual drug releasing nanoparticles, which are entirely controllable, to aid in the treatment of resistant cancer phenotypes.

Block-Copolymer Assisted Fabrication Of Anisotropic Plasmonic Nanostructures, Calbi J. Gunder

Graduate Theses/Dissertations

The anisotropic nanostructures of noble metals are of great interest for plasmonic applications due to the possibility of tuning the localized surface plasmon resonance (LSPR) across the UV-VIS-NIR without sacrificing the linewidth as well as to achieve larger local field enhancement. Here, we report a simple and promising fabrication method of anisotropic gold nanostructures film using polystyrene-b-2vinylpyridine (PS-b-P2VP) block copolymers (BCP) as a template. In this approach, PS-b-P2VP spherical micelles were first synthesized as a template followed by selective deposition of Au precursor inside P2VP core of the micelles using ethanol solution of Au salt. Subsequently, heat treatment of the …

Metal Nanoparticles/Carbon Nanotube Modified Electrodes For Voltammetric Determination Of Boron, Lokman Li̇v, Zekerya Dursun, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This study describes a sensitive and accurate voltammetric method for determination of boron using metal nanoparticles/carbon nanotube modified electrodes. The oxidation peak of Alizarin Red S (ARS) at -0.59 V in the boron-ARS complex formed in ammonium/ammonia buffer solution (pH 8.5) was evaluated as a response. The electrode modification conditions and experimental parameters affecting the peak height were optimized. The characteristics of modified electrodes were investigated using cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscope, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The limits of detection (3s$_{y/x})$ and the analytical ranges for gold nanoparticles/carbon …

Fabrication And Application Of Functional Polymer-Protein Coreshell Nanoparticles, Lin Lu

Theses and Dissertations

The study of polymer-protein nanoparticles is of increasing interest due to their various potential applications in biosensing, imaging, bioseparations, gene and drug delivery, etc. Synthetic polymers can be tailored with different functional groups and properties, therefore, they can serve as platforms to impart proteins with additional features and assist proteins to better perform biological functions. In this dissertation work, we were mainly focusing on the preparation of polymer-protein core-shell nanoparticles by synthesizing new functional polymers and assembling them with proteins for different applications. In chapter 1, a pyridine grafted diblock copolymer P(CL-g-Py)-b-PCL was prepared through ROP and CuAAC reactions. …

Structural Transformations Of Multimetallic Nanoparticles, Guangfang Li

Theses and Dissertations

Atomic-level understanding of the structural transformations of multimetallic nanoparticles (NPs) triggered by external stimuli is of vital importance to the enhancement of our capabilities to precisely fine-tailor the key structural parameters and thereby to fine-tune the catalytic properties of the NPs. In this work, I firstly show that Au-Cu bimetallic NPs demonstrate stoichiometry-dependent architectural evolutions during chemical dealloying processes and nanoporosity-evolving percolation dealloying only occurs for Au-Cu alloy NPs with Cu atomic fractions above the parting limit. The electrochemically active surface area and the specific activity of the dealloyed nanoframes can be systematically tuned to achieve the optimal electrocatalytic activity. …

Synthesis And Characterization Of Polydiene-Grafted Nanoparticles, Zaid Mohammed Abbas Alajeeli

Theses and Dissertations

This dissertation presents the design, synthesis, and characterization of polydiene grafted nanoparticles as a way to tailor nanocomposite interfaces and properties via interface design. The polymerization of dienes was done via reversible addition fragmentation chain transfer (RAFT) polymerization. The grafting of polymer chains on the surface of silica nanoparticles can be controlled through the molecular design of the RAFT agents attached to the nanoparticles surface. The properties of the nanocomposites largely depended on the interface between the particles and the polymer matrix. In the first part of this work, the polymerization of diene monomers was done on 15 nm diameter …

Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor

LSU Doctoral Dissertations

The growth and self-assembly of molecules on surfaces can be directly visualized at the molecular level using studies which combine nanoscale lithography and high-resolution imaging. Nanopatterning provides a unique and practical approach for direct views of surface changes after the key chemical steps of nanopatterning, providing landmarks and baselines for measuring growth in vertical and lateral dimensions. Controlling the arrangement of materials on surfaces at the nanoscale can be achieved using particle lithography. Arrays of well-defined nanostructures can be prepared with reproducible geometries and arrangement. Results for the preparation of nanopatterns produced with particle lithography are presented using high resolution …

Coupled Plasmon/Molecule Dynamics Near Core-Shell Nanoparticles: Synthesis, Ultrafast Characterization, And Quantum/Classical Modeling, Holden Tyler Smith

LSU Doctoral Dissertations

In this dissertation, the resonance coupling of chromaphoric dyes adsorbed on the surface of plasmonic nanoparticles (NPs) are investigated using a combined theoretical and experi- mental approach. Colloidal gold, gold-silver core-shell, silver-gold core-shell, and gold-silver- gold core-shell-shell NPs are considered. These NPs are thiolated with mercaptosuccinic acid, and malachite green dyes are adsorbed to the surface of the nanoparticle (NP) via elec- trostatic interactions. Second harmonic generation is used to determine the surface to the isotherm of the molecular dyes to the colloidal nanoparticle surface. Adsorption isotherms show that the SHG intensity increases as the concentration of dye increases, reaching …

Evaluation Of Functionalized Magnetite Nanoparticles For The Removal Of Heavy Metal Ions From Aqueous Media, Khaula A. Ai Jahoushi

Theses

Sorption is one of the most efficient techniques for the removal of heavy metal ions from waste water. It involves the use of solid materials, known as sorbents, which can be natural of synthetic in origin. Recently, synthetic nanomaterials of various compositions have been used as sorbents. Among these materials, calcium phosphate; also known as hydroxyapatite (HAp), and magnetite were previously investigated as potential sorbents. In the current study, commercial HAp, and magnetite nanoparticles as well as their physical and chemical mixtures were investigated as potential sorbents for the removal of Cd²⁺ ions from simulated wastewater. A comparison is made …

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 …

One-Pot Syntheses And Characterizations Of “Click-Able” Polyester Polymers For Potential Biomedical Applications, James F. Beach Ii

Electronic Theses & Dissertations

In this study, a synthetic polyester polymer was designed using polyethylene glycol, sorbitol, glutaric acid and 4-pentynoic acid as monomers. The synthesis was carried out using standard melt polymerization technique and catalyzed by Novozyme-435, an enzyme suitable for polyesterification of biocompatible compounds. The progress of the reaction was monitored with respect to time and vacuum exposure, with samples being subjected to standard characterization protocols. Polymers with high molecular weight and water solubility were chosen for further modification into folate-functionalized polymeric nanoparticles for targeted drug delivery to cancer cells. This was achieved by employing a solvent diffusion method, wherein the polymer …

Real-Time Atomistic Observation Of Structural Phase Transformations In Individual Hafnia Nanorods, Bethany M. Hudak, Sean W. Depner, Gregory R. Waetzig, Anjana Talapatra, Raymundo Arroyave, Sarbajit Banerjee, Beth S. Guiton

Chemistry Faculty Publications

High-temperature phases of hafnium dioxide have exceptionally high dielectric constants and large bandgaps, but quenching them to room temperature remains a challenge. Scaling the bulk form to nanocrystals, while successful in stabilizing the tetragonal phase of isomorphous ZrO₂, has produced nanorods with a twinned version of the room temperature monoclinic phase in HfO₂. Here we use in situ heating in a scanning transmission electron microscope to observe the transformation of an HfO₂ nanorod from monoclinic to tetragonal, with a transformation temperature suppressed by over 1000°C from bulk. When the nanorod is annealed, we observe with …

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 …

Design And Characterization Of Plasmonic Nanoprobes And Interparticle Interactions For Surface Enhanced Raman Scattering And Biomolecular Detection, Zakiya Skeete

Graduate Dissertations and Theses

Functional nanoparticles serve as an intriguing class of probes in medical theranostics for enabling rapid, sensitive, multiplexing, and point-of-care treatment and diagnosis. One important aspect of these applications is the exploitation of the unique plasmonic properties of certain metal nanoparticles. A key challenge is the understanding of effective harnessing of the plasmonic coupling of the nanoparticles upon interacting with the targeted biomolecular species. This thesis work focuses on investigating the interparticle interactions of chemcially-labled and bioconjugated gold and silver based nanoparticles and their influences on the plasmonic coupling for specctroscopic detection of biomolecules. Examples of the interparticle interactions include dye-mediated …

Synthesis Of Polythioether Nanoparticles Via Thiol-Alkene/Alkyne Photopolymerization In Miniemulsion, Susan E. Walley

Honors Theses

Emulsion-based processes – such as miniemulsion polymerizations – provide well-studied synthetic routes to polymer nanomaterials. Miniemulsion polymerizations are characterized as aqueous dispersions of small, narrowly distributed monomer droplets created through high shear and stabilized against Ostwald ripening/collisional degradation by addition of an appropriate surfactant and costabilizer. In this work, thiol–alkene/alkyne photopolymerization in miniemulsion is demonstrated as a simple, rapid, and one-pot synthetic approach to polythioether nanoparticles with tuneable particle size and clickable functionality. Nanoparticles with mean particle diameters ranging from 45 nm to 200 nm were synthesized through simple modifications to the miniemulsion formulation and processing parameters. Facile access to …

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 …

Biosorption Of Pharmaceuticals And Noble Metals Nanoparticles By Algal Turf Communities, Haider Abid Faraj

Dissertations

Pharmaceuticals and nanoparticles are increasingly released into the aquatic ecosystem, while removing these contaminants from waters can be challenging. This study explores the use of periphytic algal turf communities to remove these contaminants. Initially algal turfs from different locations and aquatic systems were analyzed for pharmaceuticals commonly observed in wastewater outflows. Lab-grown turfs were exposed to a mixture of six representative pharmaceuticals of different functionality (acid, base, neutral and steroidal). Analysis of water column and the algal biomass showed pharmaceutical removal rates varied, specific to each pharmaceutical. Caffeine and estradiol had the highest removal rates while carbamazepine was not removed. …

Synthesis Of Complex/Multifunctional Metal (Hydr)Oxide/Graphite Oxide/Aunps Or Agnps Adsorbents And Analysis Of Their Interactions With Chemical Warfare Agents, Dimitrios A. Giannakoudakis

Dissertations, Theses, and Capstone Projects

One of the most widely used chemical warfare agent (CWA) is mustard gas, which is a highly toxic blistering agent. In this study we investigated the interactions of mustard gas surrogates’ vapors on zinc and zirconium hydroxides and their composites with graphite oxide (GO) and/or Au or Ag nanoparticles. Even though a small quantity of reports about the detoxification of CWAs on metal oxides is reported in the literature, almost all of these studies are performed in the liquid phase. Both herein reported Zn(OH)₂ and Zr(OH)₄ showed a good adsorption performance, with the former being photoactive under visible …

Synthesis Of Discrete Transition Metal (Ni, Fe, Co, Mn) Phosphide Nanoparticles: Compositional Effect On Catalytic And Magnetic Properties, Da Li

Wayne State University Dissertations

This dissertation research is focused on the synthesis, characterization of binary and ternary transition metal (Ni, Co, Fe, Mn) phosphide nanomaterials and their catalytic and magnetic properties.

A phase-control strategy enabling the arrested-precipitation synthesis of nanoparticles of Ni5P4 and NiP2 is presented. The composition and purity of the product can be tuned by changing key synthetic levers, including the metal precursor, the oleylamine (OAm) and Trioctylphosphine (TOP) concentrations, temperature, time and the presence or absence of a moderate temperature soak step to facilitate formation of Ni and/or Ni-P amorphous nanoparticle intermediates.

New CoxFe2-xP nanoparticles (0 ≤ x ≤ 2), Co2-xMnxP …

Synthesis, Characterization, And Enhanced Magnetic Properties Of Iron Carbide Nanomaterials, Brent M. Williams

Theses and Dissertations

Permanent magnets are classified as hard magnetic materials with the main purpose of generating flux for applications such as electric motors, turbines, and hard drives. High coercivity, magnetic remanence, and saturation values with high stability are some of the requirements for permanent magnets. Rare-earth magnets including neodymium and samarium based magnets are known to have superior magnetic properties due to their high magnetocrystalline anisotropy. However, due to the price of rare-earth materials development of alternate permanent magnets composed of inexpensive materials is an ongoing process. Previously cobalt carbide (Co_xC) have shown promise as a potential rare-earth free magnet …

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles can …

Cost Effective Surface Functionalization Of Gold Nanoparticles With A Mixed Dna And Peg Monolayer For Nanotechnology Applications, Risheng Wang, Isabella Bowling, Wenyan Liu

Chemistry Faculty Research & Creative Works

A cost effective and generally applicable co-functionalization of gold nanoparticles with a mixed DNA and PEG polymers is reported. Compared to the pure DNA functionalization method, this protocol uses a much smaller amount of thiol-DNA to achieve a similar binding efficacy of gold nanoparticles with DNA origami nanostructures. The lower consumption of DNA provides a scaling-up potential for the application of DNA-nanoparticle conjugates in nanotechnology.