Nanoscience and Nanotechnology Commons^™

Electrochemical Corrosion And Protection Of Copper Foil Treated By Surface Siloxane Filming, Wei-Jun Miao, Yu-Bao Zhang, Ning-Yu Gu, Feng Liu

Journal of Electrochemistry

Copper foil specimens were immersed in hydro-alcoholic solution of 3-amino-propyl-trimethoxy-silane (γ-APS) to prepare a protective self-assembled siloxane membrane on the surface. Potentiodynamic polarization and electrochemical impedance spectroscopic tests were performed in 0.1 mol.L^-1 NaCl to evaluate the effects of the self-assembled siloxane membranes prepared at different pH of γ-APS on corrosion of copper foil. The surface morphology of siloxane membrane was studied by SEM. Experimental results revealed that the γ-APS self-assembled siloxane membranes effectively inhibited the corrosion of copper foil and the optimum anti-corrosion effect was found when the pH value of the silane solution was 7.

Electrochemical Sensing Of Guanine And Adenine Based On The Boron-Doped Carbon Nanotubes Modified Electrode, Ya-Lin Xia, Chun-Yan Deng, Juan Xiang

Journal of Electrochemistry

In this work, the boron-doped carbon nanotubes (BCNTs) modified glassy carbon (GC) electrode was simply fabricated, and the electrochemical oxidation behaviors of guanine and adenine at the BCNTs/GC electrode were investigated. Compared with the bare GC and CNTs/GC electrodes, the BCNTs-modified electrode exhibited extraordinary electrocatalytic activity towards the oxidations of guanine and adenine as indicated by the obvious increase in current responses. Moreover, the peak separation between guanine and adenine was large enough for their potential recognition in mixture without any separation or pretreatment. Therefore, the simultaneous determination of guanine and adenine was successfully achieved. The BCNTs/GC electrode showed high …

Probing And Controlling Fluid Rheology At Microscale With Magnetic Nanorods, Alexander Tokarev

All Dissertations

This Dissertation is focused on the development of new methods for characterization and control of fluid rheology using magnetic nanorods. This Dissertation consists of five chapters. In the first chapter, we review current microrheologial methods and develop a Magnetic Rotational Spectroscopy (MRS) model describing nanorod response to a rotating magnetic field. Using numerical modeling, we analyze the effects of materials parameters of nanorods and fluids on the MRS characteristic features. The model is designed for a specific experimental protocol. We introduce and examine physical parameters which can be measured experimentally. The model allows identification of MRS features enabling the calculation …

An Extension To Particle Polarizability To Predict Coupling Behavior In Periodic Nanoplasmonic Arrays, Drew Dejarnette

Graduate Theses and Dissertations

Plasmonic nanoparticles organized in arrays interact to create spectral patterns which are amplified by individual particle polarizability. It was hypothesized that particle polarizability could be used as a predictor of spectral behavior from far-field interactions within the array. Inter-particle coupling produced an extraordinary peak in extinction efficiency at wavelengths equal to or larger than the single particle plasmon resonance peak. Interactions that produced constructive coupling were found to mimic changes in the particle polarizability model. Testing of the hypothesis was performed using the coupled dipole approximation with parametric characterization of array geometries, giving specific particle size and lattice constant combinations …

Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li

Graduate Theses and Dissertations

The bottom-up colloidal synthesis opened up the possibility of finely tuning and tailoring the semiconductor nanocrystals. Numerous recipes were developed for the preparation of colloidal semiconductor nanocrystals, especially the traditional quantum dots. However, due to the lack of thorough understanding to those systems, the synthesis chemistry is still on the empirical level. CdS quantum dots synthesis in non-coordinating solvent were taken as a model system to investigate its molecular mechanism and formation process, ODE was identified as the reducing agent for the preparation of CdS nanocrystals, non-injection and low-temperature synthesis methods developed. In this model system, we not only proved …

Nanoencapsulated Copper Pthalocyanine As Photodynamic Antimicrobial Chemotherapy, Prathima Arrabelly

All Capstone Projects

The growing resistance developed by microbes towards antimicrobial agents has driven our focus on developing alternative treatment modalities such as Photodynamic antimicrobial chemotherapy (PACT). It would be difficult for the microbes to develop resistance towards singlet oxygen generated during the PACT process. Photosensitizers are the vehicles of the transfer and translation of light energy into a type II chemical reaction (singlet oxygen generation) in photodynamic antimicrobial chemotherapy. PACT is proposed as a potential, low cost approach to treatment of locally occurring infection.

Photodynamic inactivation (PDI) of Escherichia coli and Staphylococcus aureus has been studied in cultures treated with photoactivated copper …

Multidentate Resorcinarene Surfactants For The Phase Transfer Of Metal Nanoparticles And Nanodiamonds: Applications In Catalysis And Diamond Film Growth, Vara Prasad Sheela

Chemistry & Biochemistry Theses & Dissertations

One main objective of the present work is to functionalize cuboctahedral platinum nanoparticles with various multidentate resorcinarene surfactants and study their influence in determining their catalytic activity. We hypothesized that catalytically active and recyclable catalysts can be achieved by incomplete yet strong passivation of the nanoparticle surfaces by using multidentate resorcinarene surfactants. We have developed phase transfer protocols for functionalizing cuboctahedral platinum nanoparticles with resorcinarene thiol or amine. Fluorescence assay confirmed that both these nanoparticles contained almost comparable unpassivated metal area. The activity of such phase transferred nanoparticles was tested in the catalytic hydrogenation of allyl alcohol. The conversion of …

Preparation And Electrochemical Performance Of Tio2/Gns Nanocomposite As Anode Materials For Lithium-Ion Batteries, Lin-Lin Qin, Huan Zhang, Xiao-Jing Liu, Jian-Hui Xu, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The honeycomb-like porous TiO₂/graphenes (TiO₂/GNs) nanocomposite was prepared by a reflux method. SEM and TEM results showed that nanosized anatase TiO₂ (about 5~10 nm) were dispersed uniformly on the surface of the GNs. The TiO₂/GNs composite showed excellent rate and cycling performance: A stable charge capacity of 169.5 mAh·g^-1 was obtained at 30C, and can restore to 241.7 mAh·g^-1 while current went back to 1C. The stable charge capacity of TiO₂/GNs nanocomposite electrode up to 201.9 mAh·g^-1 was achieved at 10C in the first cycle, and could be …

Preparation And Characterization Of Prussian Blue Modified Nanoelectrode, Wei Wang, Bao-Fa Su, Dong-Ping Zhan

Journal of Electrochemistry

The Pt nanoelectrodes were fabricated by using a laser-based pipet puller and the recessed nanoelectrodes were prepared by etching of disk Pt nanoelectrodes wtih high frequency ac voltage. Prussian blue microcrystal was synthesized electrochemically on the both disk and recessed Pt nanoelectrodes. The strength of mechanical adhesion for the Prussian blue microcrystal on the nanoelectrode was enhanced. A novel method for the controllable synthesis of single particle is proposed, which has potential applications in modified electrodes and single particle electrocatalysis.

On The Molecular Mechanism Of Electron Transfer Of Cytochrome C Modulated By Gold Nanoparticles In Nano-Sandwich Architecture, Shou-Rui Lin, Li-Xu Wang, Xiu-E Jiang, Li-Ping Guo

Journal of Electrochemistry

The effects of adsorbed gold nanoparticles on the surface-enhanced infrared absorption (SEIRA) difference spectra of redox-induced cytochrome (Cyt) c in AuNPs/Cyt c/Au sandwich architecture were monitored by SEIRA spectroscopy. The results indicated that the intensity of SEIRA difference spectrum for the vibration of the heme was significantly increased due to the adsorption of gold nanoparticles on the Cyt c. This was induced by the electron transfer between the heme and the gold nanoparticles, which also promoted electron transfer of adsorbed protein. This study suggested a new technique for optimizing the electrochemical property of adsorbed protein.

Detection Of Pml/Rarî± Fusion Gene Using Gold Nanopaticles Modified Electrode By Chronocoulometry, Li-Man Wang, Li-Qing Lin, Shao-Huang Weng, Xin-Hua Lin, Yuan-Zhong Chen

Journal of Electrochemistry

A gold nanoparticles modified electrode was prepared by electrodeposition at constant potential. The sulfydryl modified probe was immobilized onto surface of gold nanoparticles via Au-S covalent bond and hybridized with complementary target DNA sequences, then the DNA sensor was fabricated for the detection of PML/RARα fusion gene by chronocoulometry in acute promyelocytic leukemia (APL). Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) were used to characterize the surface morphology of gold nanoparticles and the constructing process of sensor. With hexaammineruthenium(Ⅲ) chloride (RuHex) as a novel electrochemical indicator, the chronocoulometric DNA biosensor was employed to monitor artificial APL PML/RARα fusion …

Protonization Of Amino Functional Groups Confined In Nanochannels, Hong-Li Gao, Kai-Lin Zhou, Chen Wang, Su-Juan Li, Hui Zhang, Xing-Hua Xia

Journal of Electrochemistry

Protonization process is the key step of acid-base reaction and occurs in many biological processes. Study of the protonization process of molecules and/or functional groups in confined conditions would assist understanding in the acid-base theory and confinement effect of biomolecules. In this paper, we developed a novel approach to study protonization of functional groups in porous anodic alumina array nanochannels by measuring the flux of electrochemical active probes using an Au film electrochemical detector sputtered at the end of the nanochannels. The protonization status of the surface functional groups in nanochannels can change the surface charges and further modulate the …

Active Response Of Polymer Materials From External Stimuli – Solvents And Light; Grafting Reactions On Perovskite Layers, Jianxia Zhang

LSU New Orleans Theses and Dissertations

The active response of a series of polymeric materials was investigated. Both solvent activated and light activated thin films and wire systems show dynamic behaviors when exposed to different stimuli.

Solvent mediated fluxional behavior of polymer thin films involved extensive, rapid curling both on infusion and evaporation of good solvents. These films can be either lab-fabricated ones or commercial ones, and the curling behavior can be as fast as seconds. Conditions including polymer materials, chosen solvents, and film geometry can affect the behavior.

Methods that allowed for the creation and retention of distorted wire structures were also developed; the asymmetric …

Use Of Ultra High Vacuum Plasma Enhanced Chemical Vapor Deposition For Graphene Fabrication, Shannen Adcock

Graduate Theses and Dissertations

Graphene, what some are terming the "new silicon", has the possibility of revolutionizing technology through nanoscale design processes. Fabrication of graphene for device processing is limited largely by the temperatures used in conventional deposition. High temperatures are detrimental to device design where many different materials may be present. For this reason, graphene synthesis at low temperatures using plasma-enhanced chemical vapor deposition is the subject of much research. In this thesis, a tool for ultra-high vacuum plasma-enhanced chemical vapor deposition (UHV-PECVD) and accompanying subsystems, such as control systems and alarms, are designed and implemented to be used in future graphene growths. …

Electrochemical Preparation Of Nanostructural Pt-Ni And Pd-Ni Films For Ethanol Electro-Oxidation, Chen-Zhong Yao, Hui-Xuan Ma, Bo-Hui Wei

Journal of Electrochemistry

The Pt-Ni and Pd-Ni films were successfully prepared on Ti substrates by electrodeposition method. The porous Pt-Ni nanoflakes appeared to be uniform with the thickness of the slices about 10 ~ 20 nm. The porous Pd-Ni nanoparticles with a flower shape appeared to be uniform with the diameters of 50 ~ 60 nm. The XRD patterns also indicated that the Pd-Ni and Pt-Ni nanostructures have the poor crystallinity. The onset potentials of ethanol oxidation were negatively shifted to –0.74 V on Pt-Ni electrodes and –0.71 V on Pd-Ni electrodes, respectively. Addition of Ni could enhance catalytic activities and antitoxic properties …

Electrochemical Performances Of Carbon-Coated Na2Ti6O13 Nanotubes, Guo-Ran Li, Shuai Sun, Xue-Ping Gao

Journal of Electrochemistry

With rutile TiO₂ and NaOH as starting materials, the Na₂Ti₆O₁₃ nanotubes were prepared by a hydrothermal reaction. The carbon-coated Na₂Ti₆O₁₃ nanotubes were obtained by treating the Na₂Ti₆O₁₃ nanotubes for 4 h in glucose aqueous solutions containing 0.1 mol·L^-1 NaOH. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microcopy (TEM). The results showed that the dimensions of carbon-coated Na₂Ti₆O₁₃ nanotubes were 14 ~ 19 nm of outer diameter, 2 ~ 5 …

Functional Magnetic Nanoparticles, James Gass

USF Tampa Graduate Theses and Dissertations

Nanoparticle system research and characterization is the focal point of this research and dissertation. In the research presented here, magnetite, cobalt, and ferrite nanoparticle systems have been explored in regard to their magnetocaloric effect (MCE) properties, as well as for use in polymer composites. Both areas of study have potential applications across a wide variety of interdisciplinary fields.

Magnetite nanoparticles have been successfully dispersed in a polymer. The surface chemistry of the magnetic nanoparticle proves critical to obtaining a homogenous and well separated high density dispersion in PMMA. Theoretical studies found in the literature have indicated that surface interface energy …

Folate Nanoparticle Conjugates, Safwat A. Masood

All Capstone Projects

The folate receptor is overexpressed on the surface of numerous cancer cell types including those of the breast, lung, kidney, ovary, and brain. Recent interest has exploded in the use of folate to deliver payloads and imaging agents to folate receptor positive cancer cells based on several positive clinical trials including phase III trials of EC-145, which is poised to become the first folate targeted, FDA approved drug. Given the success of EC-145 and numerous other agents in the pharmaceutical pipeline, there remains a great interest in the exploitation of this technology in the delivery of nanoscale agents to folate …

Multidimensional Spectroscopy Of Semiconductor Quantum Dots, Jason Michael Bylsma

USF Tampa Graduate Theses and Dissertations

The coherent properties of semiconductor nanostructures are inherently difficult to measure and one-dimensional spectroscopies are often unable to separate inhomogeneous and homogeneous linewidths. We have refined and improved a method of performing multidimensional Fourier transform spectroscopy based on four-wave

mixing (FWM) experiments in the box geometry. We have modified our system with broadband beamsplitters in all interferometer arms, high-resolution translation stages and the ability to work in reflection geometry. By improving the phase-stability of our setup and scanning pulse delays with sub-optical cycle precision, we are able to

reproduce 2DFT spectra of GaAs multiple quantum wells. With the FWM signal …

Electrochemical Fabrication Of The Ordered Polyaniline Nanowires Array, Yan-Xin Gao, Li-Chao Sun, Su-Yuan Xie, Kang Shi

Journal of Electrochemistry

The effects of electrochemical fabrication methods in different aniline concentrations on the morphologies of polyaniline, which was polymerized on the aligned-multi-walled carbon nanotubes electrode in H₂SO₄ or HClO₄ electrolyte solution, were investigated. It was demonstrated that the polyaniline nanowires would not be prepared by cyclic voltammotry, whereas the nanowires could be obtained by the potentiostatic method without forming the ordered array. Only when the aniline concentration in HClO₄ solution was high enough, the ordered polyaniline nanowires array could be fabricated by the constant current method.

Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan

Journal of Electrochemistry

The Ag nanoparticles were prepared in aqueous solutions through a chemical reduction method and transferred from water phase to toluene phase with the protection of 1-dodecanethiol (DDT). The polished iron electrode was immersed in the DDT-protected metal nanoparticles toluene solutions to form DDT/Ag nanoparticles self-assembled mixed films. Electrochemical methods such as electrochemical impedance spectroscopy and polarization curve measurement were used to study the inhibition properties of the self-assembled films in the 0.5 mol·L^-1 H₂SO₄ solution. The appearance of elements such as S and Ag from the XPS data identified the presences of DDT and Ag nanoparticles.

Synthesis And Characterization Of Nanocomposites For Electrochemical Capacitors, Farah Alvi

USF Tampa Graduate Theses and Dissertations

Presently there are deep concerns over the environmental consequences and the consumption of non-renewable energy sources, with the accelerated greenhouse effect, triggered enormous interest in the use of renewable energy sources e.g., solar, hydropower, wind and geothermal. However the intermittent nature of harvesting renewable energy sources has recently gained considerable attention in the alternative reliable, cost effective, and environmentally friendly energy storage devices. The supercapacitor and lithium ion batteries are considered more efficient electrical energy storage devices than conventional energy storage systems.

Both devices have many useful and important applications; they could be an excellent source for high power and …

Controlling Nanoparticles Formation In Molten Metallic Bilayers By Pulsed-Laser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman

Mathematics Faculty Publications

The impacts of the two-beam interference heating on the number of core-shell and embedded nanoparticles and on nanostructure coarsening are studied numerically based on the non-linear dynamical model for dewetting of the pulsed-laser irradiated, thin (< 20 nm) metallic bilayers. The model incorporates thermocapillary forces and disjoining pressures, and assumes dewetting from the optically transparent substrate atop of the reflective support layer, which results in the complicated dependence of light reflectivity and absorption on the thicknesses of the layers. Stabilizing thermocapillary effect is due to the local thickness-dependent, steady- state temperature profile in the liquid, which is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Linear stability analysis of the model equations set for Ag/Co bilayer predicts the dewetting length scales in the qualitative agreement with experiment.

Metal Chalcogenide Nanoparticle Gel Networks: Their Formation Mechanism And Application For Novel Material Generation And Heavy Metal Remediation Via Cation Exchange Reactions, Irina Ramona Pala

Wayne State University Dissertations

METAL CHALCOGENIDE NANOPARTICLE GEL NETWORKS: THEIR FROMATION MECHANISM AND APPLICATION FOR NOVEL MATERIAL GENERATION AND HEAVY METAL REMEDIATION VIA CATION EXCHANGE REACTIONS

by

IRINA R. PALA

February 2012

Advisor: Dr. Stephanie L. Brock

Major: Chemistry

Degree: Doctor of Philosophy

The dissertation research is focused on (1) uncovering the mechanism of metal chalcogenide nanoparticle gel formation; (2) extending the cation exchange reaction protocol to zinc sulfide gel networks, with the goal of accessing new aerogel chemistries and understanding the factors that drive the process; and (3) conducting a quantitative analysis of the ability of ZnS aerogels to remove heavy metal ions …

Experimental And Theoretical Analysis Of Strain Engineered Aluminium Nitride On Silicon For High Quality Aluminium(X)Indium(Y)Gallium(1-X-Y)Nitride Epitaxy, Mihir Hemant Tungare

Legacy Theses & Dissertations (2009 - 2024)

III-Nitrides on Si are of great technological importance due to the availability of large area, epi ready Si substrates and the ability to heterointegrate with mature silicon micro and nanoelectronics. The major roadblock with realizing this is the large difference in thermal expansion coefficients and lattice constants between the two material systems. A novel technique developed in our research lab shows the potential of simultaneous and substantial reduction in dislocation and crack density in GaN on Si (111). Research undertaken in the current doctoral dissertation, validates the superior GaN quality on Si obtained using our technique and determines the factors …

(In, Al) Co-Doped Zinc Oxide As A Novel Material System For Quantum-Well Multilayer Thermoelectrics, Sean C. Teehan

Legacy Theses & Dissertations (2009 - 2024)

Waste heat recovery from low efficiency industrial processes requires high performance thermoelectric materials to meet challenging requirements. The efficiency such a device is quantified by the dimensionless figure of merit ZT=S2σT/қ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature and қ is the thermal conductivity. For practical applications these devices are only cost-effective if the ZT is higher than 2.

The Influence Of Copper Substrate Orientation On Graphene Growth, Zachary Robert Robinson

Legacy Theses & Dissertations (2009 - 2024)

This dissertation is focused on determining the influence of the copper substrate on graphene grown by \ac{CVD}. Graphene, which can be grown in single atomic layers on copper substrates, has potential applications in future electronic devices. One of the key issues for the use of graphene grown by chemical vapor deposition for device applications is the influence of defects on the transport properties of the graphene. For instance, growth on metal foil substrates results in multi-domain graphene growth because the foil substrates themselves have a variety of different surface terminations. Therefore, they don't serve as a very good template for …

A Novel Fabrication Technique For Three-Dimensional Nanostructures, Ravi Kiran Bonam

Legacy Theses & Dissertations (2009 - 2024)

Three dimensional micro- and nano-structures are commonly used in the field of Photonics, Optoelectronics, Sensors and Biological applications. Although numerous physical models are developed, a major challenge has been in their fabrication which is commonly limited to conventional layer-by-layer techniques. In this dissertation, a novel method for fabricating three dimensional structures using Electron Beam Lithography (EBL) will be presented.

Microfluidic Separation Of Live And Dead Yeast Cells Using Reservoir-Based Dielectrophoresis, Saurin Patel, Daniel Showers, Pallavi Vedantam, Tzuen-Rong Tzeng, Shizhi Qian, Xiangchun Xuan

Mechanical & Aerospace Engineering Faculty Publications

Separating live and dead cells is critical to the diagnosis of early stage diseases and to the efficacy test of drug screening, etc. This work demonstrates a novel microfluidic approach to dielectrophoretic separation of yeast cells by viability. It exploits the cell dielectrophoresis that is induced by the inherent electric field gradient at the reservoir-microchannel junction to selectively trap dead yeast cells and continuously separate them from live ones right inside the reservoir. This approach is therefore termed reservoir-based dielectrophoresis (rDEP). It has unique advantages as compared to existing dielectrophoretic approaches such as the occupation of zero channel space and …

Microscopic And Spectroscopic Analysis Of Wo3 And Ti-Doped Wo3 Thin Films, Young Taek Yun

Open Access Theses & Dissertations

Tungsten oxide (WO3) has been a subject of high interest for its unique properties, and recently for its importance in different types of industrial applications which ranges from non-emissive displays, optical, microelectronic, catalytic/photocatalytic, humidity, temperature, gas, and biosensor devices. In this study, WO3 and Ti doped thin films were prepared using radio frequency magnetron reactive sputtering at different substrate temperatures ranging from room temperature to 500 ºC in increments of 100 ºC. After forming a hypothesis based on knowledge of established WO3 properties, we attempt in this work to investigate how the doping influences the roughness and the mean grain …