Engineering Commons^™

Stability And Redispersion Of Platinum Nanoparticle Suspensions For Attachment To Dyes In Low-Cost Solar Cells, Jeffrey Rothstein

Honors Scholar Theses

The project involves optimizing the synthesis, washing, and redispersion of platinum nanoparticles. The nanoparticles are to be attached to dye molecules where they will act as nanocatalysts to reduce energy losses in low-cost dye-sensitized solar cells. The goal is to develop a process based on a pure or mixed solvent that will maintain a stable dispersion of the nanoparticles without interfering with their ability to bond with the dye molecules in the solar cell.

Novel Contrasts In Photoacoustic Tomography, Ruiying Zhang

McKelvey School of Engineering Theses & Dissertations

Photoacoustic tomography (PAT) combines rich optical contrast and high ultrasonic resolution in optically scattering tissue at depths. Taking advantage of its 100% sensitivity to optical absorption, PAT has been widely applied to structural, functional and molecular imaging, with both endogenous and exogenous contrasts, at superior depths than pure optical methods. This dissertation explores novel absorption contrast mechanisms of PAT based on optical/thermal patterns, endogenous cellular chromophores, nanoparticles, small-molecule dyes and genetically-encoded proteins. With these novel contrasts, the proof-of-concept applications of PAT have been extended to include homogenous flow measurements, targeted angiogenesis imaging and therapy, label-free white blood cell imaging, 3D-whole-organ …

Elucidating The Effects Of Metabolic State On Nanoparticle Distribution In Mice And In Vitro Uptake, Kevin James Quigley

Doctoral Dissertations

Since almost 70% of the U.S. population over 20 years old is overweight and 30% is obese, with much of the western world following suit, many patients that will potentially be administered circulating nanoparticles designed to localize to tumors and avoid non-target areas will have significant amounts of white adipose tissue (WAT), enlarged livers, and additional metabolic complications such as type 2 diabetes. However, studies on nanoparticle biodistribution and efficacy take place almost without exception in lean rodents with healthy metabolic states. In this work, I determined the biodistribution of model nanoparticles – neutral filomicelles and polystyrene spheres both carrying …

Coarse-Grained Simulations Of The Self-Assembly Of Dna-Linked Gold Nanoparticle Building Blocks, Charles Wrightsman Armistead

Graduate Theses and Dissertations

The self-assembly of nanoparticles (NPs) of varying shape, size, and composition for the purpose of constructing useful nanoassemblies with tailored properties remains challenging. Although progress has been made to design anisotropic building blocks that exhibit the required control for the precise placement of various NPs within a defined arrangement, there still exists obstacles in the technology to maximize the programmability in the self-assembly of NP building blocks. Currently, the self-assembly of nanostructures involves much experimental trial and error. Computational modeling is a possible approach that could be utilized to facilitate the purposeful design of the self-assembly of NP building blocks …

Mechanism Of Interaction Of Peptide Modified Nanoparticles With Porphyromonas Gingivalis., Ankita Jain

Electronic Theses and Dissertations

Studies suggest that P. gingivalis functions as a keystone pathogen and interacts with primary colonizers in the supragingival biofilm such as S. gordonii. This interaction contributes to the initial colonization of the oral cavity by P. gingivalis and thus represents a potential target for therapeutic intervention. We have identified a peptide (BAR) derived from the streptococcal SspB protein that functions to inhibit P. gingivalis adherence to S. gordonii. In addition, we showed that nanoparticles (NPs) functionalized with BAR inhibit this interaction more potently than free soluble peptide, possibly by promoting interaction with P. gingivalis at higher valency than …

Electrochemical Fabrication Of Energetic Thin Films, Jonathan J. Coleman

Chemical and Biological Engineering ETDs

Current thermal battery heat sources suffer from slow reaction propagation rates and require extreme care when handling to protect from inadvertent ignition sources. Nanostructured intermetallic heat sources are strong candidates for improved heat sources as they have high enthalpy of reaction, are highly conductive before and after firing and are completely gasless reactions. Current fabrication methods of these heat sources rely on a PVD multistep layering process that is time and capital intensive, and cost prohibiting to their use. The composition and nanostructuring these films require can be provided with electrochemical codeposition, where the two components (aluminum and nickel) are …

Magnetoelectric Nanoparticles: Paradigm Shift In Biomolecular Diagnostics, Chooda Mani Khanal

FIU Electronic Theses and Dissertations

Recently discovered multiferroic nanoparticles (MFNs) known as magnetoelectric nanoparticles (MENs) promise to revolutionize next-generation biomedical diagnostic techniques and enable rapid and cost-effective screening of lethal diseases. Due to the quantum-mechanically caused intrinsic magnetoelectric (ME) effect, these nanoparticles display strongly coupled magnetic and electric moments and thus provide a unique pathway to monitor and optionally control intrinsic characteristics of bio organisms via application of external magnetic fields. Due to the ME effect, when placed in the microenvironment of a biomolecular sample, MENs’ magnetic properties change to reflect the molecular nature of the sample. Such an unprecedented intrinsic connection to cells and …

Ginseng Polysaccharides Nanoparticles - Synthesis, Characterization, And Biological Activity, Kazi Farida Akhter

Electronic Thesis and Dissertation Repository

North American (NA) ginseng is a widely used medicinal plant. Polysaccharides (PS), the major medicinal fractions derived from NA ginseng root, have been shown several biological activities including anti-carcinogenic, anti-aging, immunostimulatory and antioxidant activity. This work focused on nanoprocessing of ginseng PS for enhancing their immunostimulation. Herein, we have developed a novel microfluidic approach to synthesize ginseng PS nanoparticles (NPs) from NA ginseng root. The microfluidics was found to provide unimodal PS spheres down to 20 nm with very narrow particle size distributions. In addition, the immunostimulating effect was investigated on Murine macrophage cell lines, with the results revealing an …

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …

Effect Of Aggregation And Particle Size On The Thermal Conductivity Of Nickel-Epoxy Nanocomposites, Jacob M. Faulkner, Xiangyu Li, Xiulin Ruan Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microprocessor advancements have been stunted in recent years by inadequate means of heat dissipation as power continues to grow and size continues to shrink. One way to increase thermal conductivity while maintaining electrical insulation is to add metal nanoparticles to a polymer matrix. This cheap material has become a popular thermal interface for this reason. However, optimization of the interface is dependent upon a number of factors including particle size, shape, orientation, and aggregation. Various theoretical models and numerical approximations have been developed to find the effective thermal conductivity of such nanocomposites, but none has been able to fully incorporate …

Enhanced And Tunable Optical Quantum Efficiencies From Plasmon Bandwidth Engineering In Bimetallic Coag Nanoparticles, A. Malasi, H. Taz, M. Ehrsam, J. Goodwin, H. Garcia, Ramki Kalyanaraman

Faculty Publications and Other Works -- Materials Science & Engineering

Plasmonic nanoparticles are amongst the most effective ways to resonantly couple optical energy into and out of nanometer sized volumes. However, controlling and/or tuning the transfer of this incident energy to the surrounding near and far field is one of the most interesting challenges in this area. Due to the dielectric properties of metallic silver (Ag), its nanoparticles have amongst the highest radiative quantum efficiencies (η), i.e., the ability to radiatively transfer the incident energy to the surrounding. Here we report the discovery that bimetallic nanoparticles of Ag made with immiscible and plasmonically weak Co metal can show comparable and/or …

Life Cycle Assessment And Comparison Of Magnesium Oxide Nanoparticles Prepared By Aqueous And Microwave Synthesis Methods, Jesse Cartland

Materials Engineering

Abstract: Magnesium oxide nanoparticles are being used increasingly as catalysts for organic synthesis, fuel oil additives, and CO₂ adsorbents. There are many ways to produce magnesium oxide nanoparticles, but there is little information available regarding the environmental costs of production. As demand for environmentally friendly materials increases, it is important to understand environmental impact differences between various production methods. This study will compare the differences in embodied energy and global warming potential (GWP) between two synthesis methods: microwave combustion synthesis (microwave synthesis) and oxidation of magnesium hydroxide (aqueous synthesis). The resulting nanoparticles were characterized using scanning electron microscopy (SEM), …

Sensing Gyroscopic Properties Of Rotating Magnetic Nanoparticles In Solution, Brian Gerald Krug

Dissertations

A new sensor using magnetic nanoparticles and rotating magnetic fields has been developed. By spinning the nanoparticles in a rotating magnetic field, it is feasible to infer angular position and inertia if an external force is applied to the system. The nanoparticles are treated as a multitude of miniature gyroscopes whose overall effect can be combined as one single gyroscope. Two sensors were built to test the feasibility, both containing Fe3O4 nanoparticles.

The typical input current was 250 milliamps. When the sensor deviated from its magnetic axis by a small angle, the input current changed between 1 and 2 milliamps …

Graphene Quantum Dots-Based Drug Delivery For Ovarian Cancer Therapy, Yiru Qin

USF Tampa Graduate Theses and Dissertations

Ovarian cancer, one of the most dreadful malignancies of the female reproductive system, poses a lethal threat to women worldwide. In this dissertation, the objective was to introduce a novel type of graphene quantum dots (GQDs) based nano-sized drug delivery systems (DDS) for ovarian cancer treatment. As a starting point, the facile synthesis method of the GQDs was established. Subsequently, the targeting ligand,folic acid (FA), was conjugated to GQDs. Next, a FDA approved chemotherapeutic drug, Doxorubicin (DOX), was loaded to form the GQDs-FA-DOX nano-conjugation as the DDS. Moreover, the uptake profile and anti-cancer effect of the GQDs-FA-DOX were validated in …

Symbiotic Plasmonic Nanomaterials: Synthesis And Properties, Abhinav Malasi

Doctoral Dissertations

Metal particles of the dimensions of the order of 1 to 100's of nanometers show unique properties that are not clearly evident in their bulk state. These nanoparticles are highly reactive and sensitive to the changes in the vicinity of the particle surface and hence find applications in the field of sensing of chemical and biological agents, catalysis, energy harvesting, data storage and many more. By synthesizing bimetallic nanoparticles, a single nanoparticle can show multifunctional characteristics. The focus of this thesis is to detail the synthesis and understand the properties of bimetallic nanomaterial systems that show interesting optical, chemical, and …

The Effect Of Mechano-Chemical Activation Of Fly Ash- Nanoparticle Blends On Performance Of Cement Based Composites And Self-Consolidating Concrete, Rani G K Pradoto

Theses and Dissertations

Other than water, portland cement concrete is the most used commodity. Major parts of civil and transportation infrastructure, including bridges, roadway pavements, dams, and buildings are made of concrete. Because of wide-scale applications of these important structures in different climatic zones and associated exposures, concrete durability is often of major concern. In 2013, the study of American Society of Civil Engineers (ASCE) estimated that one-third of America’s major roads are in poor or mediocre condition [1]. The same article reports that annual investments of $170 billion on roads and $20.5 billion for bridges are needed to substantially improve the condition …

Nanostructured Organic/Inorganic Semicondutor Photovoltaics: Investigation On Morphology And Optoelectronics Performance, Aruna Wanninayake

Theses and Dissertations

Organic solar cell is a promising technology because of the versatility of organic materials in terms of tunability of their electrical and optical properties. In addition, their relative insensitivity to film imperfections potentially allows for very low-cost high-throughput roll-to-roll processing. However, the power conversion efficiency of organic solar cell is still limited and needs to be improved in order to be competitive with grid parity. This work is focused on the design and characterization of a new organic/inorganic hybrid device to enhance the efficiency factors of bilayer organic solar cells such as: light absorption, exciton diffusion, exciton dissociation, charge transportation …

Magnetism Of Magnetite Nanoparticles As Determined By Mössbauer Spectroscopy, Hien-Yoong Hah

Masters Theses

Fe₃O₄ [Magnetite] nanoparticles have magnetism that differs greatly from their bulk counterparts. Whereas bulk Fe₃O₄ is a ferrimagnet, single-domain Fe₃O₄ nanoparticles have been found to be superparamagnetic. This allows for increased magnetization of the nanoparticles compared to the bulk when in a magnetic field. For most paramagnets, magnetization requires applied fields of a few Tesla at low temperatures. This is achievable through the application of superconducting magnets. In superparamagnets, the high susceptibility of the particles allows magnetization through a Nd-Fe-B permanent magnet at room temperature. This is caused by an increased …

Recent Progresses In Molybdenum-Based Electrocatalysts For The Hydrogen Evolution Reaction, Ze-Xing Wu, Jie Wang, Jun-Po Guo, Jing Zhu, De-Li Wang

Journal of Electrochemistry

Electrochemical catalytic production of hydrogen has been considered as a promising and sustainable strategy for clean and renewable energy technologies. Molybdenum-based non noble metal catalysts for the hydrogen evolution reaction have attracted extensive attention due to its effective catalytic performance. In this review, the recent progresses in molybdenum-carbide, phosphide, nitride and sulfide electrocatalysts are presented. In addition, the strategies to improve the catalytic performance are analyzed and the prospects for the future development trends are expected.

Heating Element Including Carbon Nanotube (Cnt) Layer, Santhosh Kumar Loganathan, Virginie Rollin, Daewon Kim

Publications

Apparatus , materials , and techniques and techniques herein can include providing a deposited layer comprising a com posite material including carbon nanotubes ( CNTs ) . Accord ing to various examples , the composite can be applied to a substrate such as using a solution containing CNTs and other constituents such as sulfur . The solution can be spray applied to a substrate , or spin - coated upon a substrate , such as to provide a uniform , conductive , and optically - transpar ent film layer . In one application , such a film layer can be …

Mens Doped Adhesive And Influence On Fracture Toughness, Kao Z. Yang

FIU Electronic Theses and Dissertations

Composites are in high demand; however, fasteners are often required for joining process and can reduce their advantages. One solution is adhesive bonding, but uncertainty exists regarding long term durability and the ability to interrogate bonds noninvasively. One potential solution to qualify bond integrity over its service life is to dope an adhesive with magneto-electric nanoparticles (MENs). MENs can yield output magnetic signatures that are influenced by bond quality and damage state. In this study, adhesives have been doped with MENs prior to bonding at 1% volume concentration. For optimum implementation, this health monitoring system should be evaluated for effects …

Ultrahigh Field Magnetic Resonance Imaging – Technical Development And Translational Applications, Judy Alper

Dissertations and Theses

Magnetic resonance imaging (MRI) may be used to provide detailed images of the human body with excellent soft tissue contrast. Alongside its current widespread clinical applications for diagnosis and treatment, MRI allows researchers to measure structure and function of different tissue types in order to advance our understanding of human biology and enable new medical applications of MRI. In particular, diseases affecting nerves and vessels, such as trigeminal neuralgia, with uncertain etiology can be studied using multiple MRI modalities so that treatment planning can we more effective and patient outcomes can be improved. Ultrahigh field MRI scanners, such as those …

Dlvo Approximation Methods For Predicting The Attachment Of Silver Nanoparticles To Ceramic Membranes, Anne M. Mikelonis, Sungmin Youn, Desmond F. Lawler

All Engineering Faculty Research

This article examines the influence of three common stabilizing agents (citrate, poly(vinylpyrrolidone) (PVP), and branched poly(ethylenimine) (BPEI)) on the attachment affinity of silver nanoparticles to ceramic water filters. Citrate-stabilized silver nanoparticles were found to have the highest attachment affinity (under conditions in which the surface potential was of opposite sign to the filter). This work demonstrates that the interaction between the electrical double layers plays a critical role in the attachment of nanoparticles to flat surfaces and, in particular, that predictions of double-layer interactions are sensitive to boundary condition assumptions (constant charge vs constant potential). The experimental deposition results can …

Expeditious And Eco-Friendly Hydrothermal Polymerization Of Pedot Nanoparticles For Binderfree High Performance Supercapacitor Electrodes, Murugesan Rajesh, C Justin Raj, Byung Chul Kim, Ramu Manikandan, Sung Jin Kim, Sang-Yeup Prof Sang-Yeup Park, Kwangsoo Lee, Kook Hyun Yu

Australian Institute for Innovative Materials - Papers

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a promising conjugated polymer that has attracted attention because of its outstanding electronic properties, useful for a wide range of applications in energy storage devices. However, synthesis of high-quality PEDOT occurs via vapour phase polymerization and chemical vapour deposition techniques using extrinsic hard templates or complicated experimental setups. This study introduces a simple hydrothermal polymerization technique using ferric chloride (FeCl3) as an oxidizing agent to overcome the above drawback, which results in good conductive, crystalline PEDOT nanodendrites and nanospheres. The effects of varying the molar ratio of FeCl3 oxidant were investigated in terms of the structural, morphological …

Encapsulation Of Fe3o4 Nanoparticles Into N, S Co-Doped Graphene Sheets With Greatly Enhanced Electrochemical Performance, Zunxian Yang, Kun Qian, Jun Lv, Wenhuan Yan, Jiahui Liu, Jingwei Ai, Yuxiang Zhang, Tailiang Guo, Xiongtu Zhou, Sheng Xu, Zaiping Guo

Faculty of Engineering and Information Sciences - Papers: Part A

Particular N, S co-doped graphene/Fe₃O₄ hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe₃O₄ nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe₃O₄ composite electrode exhibits a high initial reversible capacity …

Synchrotron Activation Radiotherapy: Effects Of Dose-Rate And Energy Spectra To Tantalum Oxide Nanoparticles Selective Tumour Cell Radiosensitization Enhancement, Elette Engels, Michael L. F Lerch, Moeava Tehei, Konstantin K. Konstantinov, Susanna Guatelli, Anatoly B. Rosenfeld, Stephanie Corde

Faculty of Engineering and Information Sciences - Papers: Part A

Synchrotron radiation is unique in its ability to deliver dose at high dose rates using kiloelectronvolt photons. We are investigating the use of Tantalum pentoxide (Ta2O5) nano-structured particles (NSPs) that are to date unexplored in synchrotron radiation fields as they have high atomic number (Z=73) are biocompatible and are therefore potential radio sensitizers. We exposed cell culture flasks containing 9L gliosarcoma tumour cells or Madin-Darby Canine Kidney (MDCK) non-tumour cells to the NSPs and treated the cells using a broad synchrotron beam (140 keV median energy; average dose rate of 50 Gy/s) at the Australian Synchrotron. We compare the results …

Synthesis And Characterization Of Curcumin Polymer For Application In Radiation Induced Lung Damage, Mark C. Bailey

Theses and Dissertations--Chemical and Materials Engineering

Radiotherapy is used as a primary treatment for many cancers, including lung cancer. Although radiotherapy has proven to be an effective cancer treatment, its use is heavily limited due to the peripheral toxicity to healthy tissue. In this work, the antioxidant, curcumin, was tested as a radioprotectant to reduce radiation damage to healthy cells. Curcumin has been limited in use due to its poor bioavailability. In order to avoid problems associated with free curcumin delivery, curcumin poly(beta-amino ester) (CPBAE) was synthesized.

The first study investigated the in vitro radioprotection effect of curcumin in HUVEC dosed with gamma radiation. Cells treated …

Improving Nano-Drug Delivery By Using Near-Real Time Sensing And Feedback, Pratik Adhikari

Doctoral Dissertations

Personalized medicine, seen as the solution to address the variability among the individuals, is the movement which proposes customization of medical procedures based on the need of the patient during the stages of prevention, diagnosis, treatment, and follow up. As the technology in medicine expands and newer methods of diagnosis and treatment are introduced in the clinic, real time data from the procedures is critical to assess the performance at point of care. Real time feedback, through collection of data at point of care would help make informed clinical decisions, potentially improving the efficacy of the treatment. In this dissertation, …

Bioactive Poly(Beta-Amino Ester) Biomaterials For Treatment Of Infection And Oxidative Stress, Andrew L. Lakes

Theses and Dissertations--Chemical and Materials Engineering

Polymers have deep roots as drug delivery tools, and are widely used in clinical to private settings. Currently, however, numerous traditional therapies exist which may be improved through use of polymeric biomaterials. Through our work with infectious and oxidative stress disease prevention and treatment, we aimed to develop application driven, enhanced therapies utilizing new classes of polymers synthesized in-house. Applying biodegradable poly(β-amino ester) (PBAE) polymers, covalent-addition of bioactive substrates to these PBAEs avoided certain pitfalls of free-loaded and non-degradable drug delivery systems. Further, through variation of polymer ingredients and conditions, we were able to tune degradation rates, release profiles, cellular …

Bioresponsive Polymer Coating On Nanoparticles, Tunyaboon Laemthong

Masters Theses

"Nanotechnology incorporated with molecular biology became a promising way to treat cancer. The size of nanoparticles enables them to overcome the side effects noticed in cancer treatment like chemotherapy and surgery. Various types and shapes of nanoparticles have been synthesized and used in drug delivery to tumor sites. However, one of problems of using these nanoparticles is the aggregation after injecting them into human body due to flow rate of bloodstream. The coagulation and aggregation will result in clogging blood vessel and lower therapeutic efficacy.

In this thesis, a solution to the aggregation problem was proposed, which is coating biopolymer …