Nanoscience and Nanotechnology Commons^™

Resistive-Pulse Analysis Of Single Phospholipid Vesicles Using Quartz Nanochannels, Jonathan T. Cox, Bo Zhang

Journal of Electrochemistry

We report the uses of resistive-pulse method and quartz nanochannels for the detection and size analysis of single vesicles. Cylindrical shape quartz nanochannels have been used to detect single phospholipid vesicles ranging from 100 to 300 nm and polystyrene nanoparticles ranging from 170 to 400 nm in diameter. Translocations of single vesicles and nanoparticle were detected as individual square current pulses, which could be used to determine particle size. Our results show excellent agreement between the particle/vesicle sizes obtained from nanochannels and those from dynamic light scattering (DLS) and scanning electron microscopy (SEM). This electronic-based method was found to be …

Comparison Of Oxygen Reduction Reaction Activity Of Pt-Alloy Nanocubes, Yongan Tang, Lin Dai, Shouzhong Zou

Journal of Electrochemistry

Alloying Pt with the first row non-noble transition metals has been demonstrated to increase the catalytic activity toward oxygen reduction reaction (ORR), which is the cathode reaction of the proton exchange membrane fuel cells (PEMFCs) and metal-air batteries. However, how much the ORR activity improvement comes from the alloying elements remains controversial. In this paper, the nanocubes of PtMn, PtFe, PtCo, and PtNi with the similar size and composition were prepared and their ORR activities were explored, in order to investigate the effects of alloying elements on the catalytic activity. The use of cubic shape particles minimizes the contribution to …

Rutile Tio2 Nanosheet Arrays Planted On Magnetron Sputtered Ti Metal Layers For Efficient Perovskite Solar Cells, Nang Zhang, Meidan Ye, Xiaoru Wen, Changjian Lin

Journal of Electrochemistry

In this work, vertical rutile titanium oxide (TiO₂) nanosheet arrays (NSAs) were firstly hydrothermally grown on the top of thin titanium (Ti) metal layers which were loaded on fluorine doped tin oxide (FTO) substrates by the DF magnetron sputtering deposition method. After an annealing post-treatment, the Ti metal layers were transformed into the compact TiO₂ layers with a strong connection between the rutile TiO₂ NSAs and the FTO substrates. For comparison, the rutile TiO₂ NSAs were similarly planted over two compact TiO₂ layers fabricated through atomic layer deposition (ALD) and spin coating (SC) methods, …

Electrodeposition Of Ruo2 Layers On Tio2 Nanotube Array Toward Co2 Electroreduction, Bei Jiang, Lina Zhang, Xianxian Qin, Wenbin Cai

Journal of Electrochemistry

RuO₂/TiO₂ composite materials have multitude of electrocatalytic applications including but not limited to CO₂ reduction reaction (CO₂RR). RuO₂/TiO₂ electrodes were previously prepared by repetitive coating and thermal decomposition (TD) of a Ru(III) precursor solution on Ti substrate. In this work, electrochemical potential cycling is applied to deposit amorphous RuO₂ (α-RuO₂) layers onto TiO₂ nanotube array (TNA) (RuO₂^CV/TNA) preformed on Ti foil. SEM, GIXRD, and voltammetry are applied to characterize the structures of the resulting RuO₂^CV/TNA. Ru loading on the RuO_{2 …}

Molecular And Biochemical Technologies For Modifying Plant Cell Walls And Producing Functional Biobased Products, Ningning Zhang

Student Theses and Dissertations

There is a continuing need for new molecular and biochemical processing technologies to more sustainably utilize biomass such as sugar beet pulp for environmental and economic benefit. This research project addressed the overarching research hypothesis that innovative molecular and biochemical technologies can enable more efficient processing of plant biomass and generate renewable biobased products for food and industrial use. Specifically, this research investigated upstream processing technologies toward re-engineering the plant cell wall for improved biomass processability and downstream processing technologies for efficient cell wall-depolymerizing (CWD) enzyme production and biomass processing. There were two Specific Aims addressed in this project: 1.) …

Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

No abstract provided.

Dna Directed Assembly Of Gold-Tipped Metallic Single-Walled Carbon Nanotubes Into Electrical Devices, Ronald D. Salesky

Nanoscience and Microsystems ETDs

Carbon nanotubes have rightfully been regarded as a wonder material since their discovery by Iijima in 1991 and the subsequent elucidation of their many material properties. Their extreme strength is 10-fold higher than any industrial fiber. Their current density carrying capability is orders of magnitude higher than copper without failure from electromigration. Their high thermal conductivity bests diamond, and their structural versatility leads to either semiconducting or metallic electronic character. These properties all make the integration of carbon nanotubes into functional devices of high value. However, they remain a material of largely unrealized potential due to several challenges that arise …

Method And Shear-Driven Micro-Fluidic Pump, Nihad E. Daidzic

Aviation Department Publications

United States Patent Application, Publication Number US 2017/0096990 A1, Publication Date April 6, 2017.

An example includes an apparatus to pump a fluid. The apparatus includes a housing extending along a length defining an elongate interior, an actuator in the housing, conforming to the elongate interior, the actuator including a plurality of lumens, each having a length extending substantially parallel to the elongate interior, each from around 10 to 200 micrometers across and an actuator configured to oscillate the actuator in the actuator housing along the length of the elongate interior with a rate differential between movement in a first …

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …

Primary Blast Waves Induced Brain Dynamics Influenced By Head Orientations, Yi Hua, Yugang Wang, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

There is controversy regarding the directional dependence of head responses subjected to blast loading. The goal of this work is to characterize the role of head orientation in the mechanics of blast wave-head interactions as well as the load transmitting to the brain. A three-dimensional human head model with anatomical details was reconstructed from computed tomography images. Three different head orientations with respect to the oncoming blast wave, i.e., front-on with head facing blast, back-on with head facing away from blast, and side-on with right side exposed to blast, were considered. The reflected pressure at the blast wave-head interface positively …

Enhanced Performance Of Planar Perovskite Solar Cells Using Low-Temperature Solution-Processed Al-Doped Sno2 As Electron Transport Layers, Hao Chen, Detao Liu, Yafei Wang, Chenyun Wang, Ting Zhang, Peng Zhang, Hojjatollah Sarvari, Zhi Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

Lead halide perovskite solar cells (PSCs) appear to be the ideal future candidate for photovoltaic applications owing to the rapid development in recent years. The electron transport layers (ETLs) prepared by low-temperature process are essential for widespread implementation and large-scale commercialization of PSCs. Here, we report an effective approach for producing planar PSCs with Al³⁺ doped SnO₂ ETLs prepared by using a low-temperature solution-processed method. The Al dopant in SnO₂ enhanced the charge transport behavior of planar PSCs and increased the current density of the devices, compared with the undoped SnO₂ ETLs. Moreover, the enhanced electrical …

Electronic Properties Of A New All-Inorganic Perovskite Tlpbi3 Simulated By The First Principles, Zhao Liu, Ting Zhang, Yafei Wang, Chenyun Wang, Peng Zhang, Hojjatollah Sarvari, Zhi Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

All-inorganic perovskites have been recognized as promising photovoltaic materials. We simulated the perovskite material of TlPbI₃ using ab initio electronic structure calculations. The band gap of 1.33 eV is extremely close to the theoretical optimum value. Compared TlPbI₃ with CsPbI₃, the total energy (−3980 eV) of the former is much lower than the latter. The partial density of states (PDOS) of TlPbI₃ shows that a strong bond exists between Tl and I, resulting in the lower total energy and more stable existence than CsPbI₃.

Focused Electron Beam Induced Deposition Of Copper With High Resolution And Purity From Aqueous Solutions, Samaneh Esfandiarpour, Lindsay Boehme, J. Todd Hastings

Electrical and Computer Engineering Faculty Publications

Electron-beam induced deposition of high-purity copper nanostructures is desirable for nanoscale rapid prototyping, interconnection of chemically synthesized structures, and integrated circuit editing. However, metalorganic, gas-phase precursors for copper introduce high levels of carbon contamination. Here we demonstrate electron beam induced deposition of high-purity copper nanostructures from aqueous solutions of copper sulfate. The addition of sulfuric acid eliminates oxygen contamination from the deposit and produces a deposit with ~95 at% copper. The addition of sodium dodecyl sulfate (SDS), Triton X-100, or polyethylene glycole (PEG) improves pattern resolution and controls deposit morphology but leads to slightly reduced purity. High resolution nested lines …

A Study Of Iron-Nitrogen-Carbon Fuel Cell Catalysts: Chemistry – Nanostructure – Performance, Michael J. Workman

Nanoscience and Microsystems ETDs

Fuel cells have the potential to be a pollution-free, low-cost, and energy efficient alternative to the internal combustion engine for transportation and small-scale stationary power applications. The current state of fuel cell technology has already achieved two of these three lofty goals. The remaining barrier to wide-scale deployment is the high cost, which is primarily caused by dependence on large amounts of platinum to catalyze the energy conversion reactions. To overcome this barrier and facilitate the integration of fuel cells into mainstream applications, research into a new class of catalyst materials that do not require platinum is needed.

There has …

Intracellular Nanoparticle Dynamics Affected By Cytoskeletal Integrity, Martha E. Grady, Emmabeth Parrish, Matthew A. Caporizzo, Sarah C. Seeger, Russell J. Composto, David M. Eckmann

Mechanical Engineering Faculty Publications

The cell interior is a crowded chemical space, which limits the diffusion of molecules and organelles within the cytoplasm, affecting the rates of chemical reactions. We provide insight into the relationship between non-specific intracellular diffusion and cytoskeletal integrity. Quantum dots entered the cell through microinjection and their spatial coordinates were captured by tracking their fluorescence signature as they diffused within the cell cytoplasm. Particle tracking revealed significant enhancement in the mobility of biocompatible quantum dots within fibrosarcoma cells versus their healthy counterparts, fibroblasts, as well as in actin destabilized fibroblasts versus untreated fibroblasts. Analyzing the displacement distributions provided insight into …

Recent Advances On Iron Oxide Magnetic Nanoparticles As Sorbents Of Organic Pollutants In Water And Wastewater Treatment, Angela M. Gutierrez, Thomas D. Dziubla, J. Zach Hilt

Superfund Research Center Faculty Publications

The constant growth in population worldwide over the past decades continues to put forward the need to provide access to safe, clean water to meet human needs. There is a need for cost-effective technologies for water and wastewater treatment that can meet the global demands and the rigorous water quality standards and at the same maximizing pollutant efficiency removal. Current remediation technologies have failed in keeping up with these factors without becoming cost-prohibitive. Most recently, nanotechnology has been sought as the best alternative to increase access to water supplies by remediating those already contaminated and offering ways to access unconventional …

Characterization And Analysis Of Real-Time Capillary Convective Pcr Toward Commercialization, Xianbo Qiu, Shiyin Zhang, Lanju Mei, Di Wu, Ke Li, Shengxiang Ge, Xiangzhong Ye, Ningshao Xia, Michael G. Mauk

Mechanical & Aerospace Engineering Faculty Publications

Almost all the reported capillary convective polymerase chain reaction (CCPCR) systems to date are still limited to research use stemming from unresolved issues related to repeatability, reliability, convenience, and sensitivity. To move CCPCR technology forward toward commercialization, a couple of critical strategies and innovations are discussed here. First, single- and dual-end heating strategies are analyzed and compared between each other. Especially, different solutions for dual-end heating are proposed and discussed, and the heat transfer and fluid flow inside the capillary tube with an optimized dual-end heating strategy are analyzed and modeled. Second, real-time CCPCR is implemented with light-emitting diode and …

Formation Of Mound-Like Multiscale Surface Structures On Titanium By Femtosecond Laser Processing, Edwin Peng, Alfred Tsubaki, Craig A. Zuhlke, Ryan Bell, Meiyu Wang, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Surface Functionalization Technique • Femtosecond Laser Surface Processing (FLSP) • Utilize high power, femtosecond (10-15 s) laser pulses • Produce self-organized, multiscale surface micro/nanostructures • Diverse range of applicable substrates: semiconductors, metals, polymers, & composites

Why? • What are the different types of FLSP structures on Ti? • Physical evidence needed for FLSP formation models • Optimize FLSP of Ti for biomedical & other applications

How? • Obtain evidence of mound growth processes by examining underlying microstructure • Utilize dual beam Scanning Electron Microscope-Focused Ion Beam instrument to cross section surface structures & fabricate transmission electron microscopy samples

Aligning Electronic Energy Levels On The Anatase Tio2(101) Surface, Jun-Jie Zhao, Jun Cheng

Journal of Electrochemistry

As one of the most commonly-used materials for photocatalysis and solar energy conversion, titanium dioxide (TiO₂) has been extensively studied for more than 40 years. Its photoelectrochemical activity crucially depends on the band positions at the interface. In this work, the valence band maximum (VBM) and conduction band minimum (CBM) of a model TiO₂ surface are computed using the standard work function method at the level of Perdew-Burke-Ernzerhof (PBE) density functional, which are then converted to the scale of the standard hydrogen electrode (SHE) by subtracting the absolute SHE potential. Comparing with the rutile TiO₂(110) …

Effect Of Pressure On Ion Selectivity In Biomimetic Nanopores With Ph-Tunable Polyelectrolyte Brushes, Hui-Xia Shan, Zhen-Ping Zeng, Li-Xian Ye, Feng Shu

Journal of Electrochemistry

Biomimetic ionic channels of synthetic nanopores functionalized with pH-tunable polyelectrolyte (PE) brushes have significant application potentials for active transport control of ions, fluids, and bioparticles on the nanoscale. Ion selectivity is an important phenomenon of ion transport in nanofluidic devices, which has great theoretical significance and practical values. We propose a pressure control scheme to control the ion selectivity in biomimetic nano-systems with pH-tunable PE brushes. Effects of the solution properties (i.e., pH and background salt concentration), the applied voltage and pressure on ion selectivity are comprehensively investigated. The results show that ion selectivity is sensitive to pressure. Unlike the …

Direct Electrochemistry Of Glucose Oxidase Based On Ws2 Quantum Dots And Its Biosensing Application, Chen-Lu Li, Hua-Ping Peng, Zhong-Nan Huang, Yi-Lun Sheng, Pei-Wen Wu, Xin-Hua Lin

Journal of Electrochemistry

In this study, a novel electrochemical glucose biosensor has been developed by immobilizing glucose oxidase (GOx) on tungsten disulfide quantum dots (WS₂ QDs) on the surface of glassy carbon electrode (GCE). Transmission electron microscopy, UV-vis spectroscopy and cyclic voltammetry were employed to characterize the morphology, structure, and electrochemical behaviors of the as-prepared WS₂ QDs and the biofilm modified electrode. The results suggested that the WS₂ QDs could accelerate the electron transfer between the electrode and the immobilized enzyme, which enabled the direct electrochemistry of GOx without any electron mediator. Besides, the immobilized GOx in WS₂ QDsfilm …

Single Molecule-Level Study Of Donor-Acceptor Interactions And Nanoscale Environment In Blends, Nicole Quist, Rebecca Grollman, Jeremy Rath, Alex Robertson, Michael Haley, John E. Anthony, Oksana Ostroverkhova

Chemistry Faculty Publications

Organic semiconductors have attracted considerable attention due to their applications in low-cost (opto)electronic devices. The most successful organic materials for applications that rely on charge carrier generation, such as solar cells, utilize blends of several types of molecules. In blends, the local environment strongly influences exciton and charge carrier dynamics. However, relationship between nanoscale features and photophysics is difficult to establish due to the lack of necessary spatial resolution. We use functionalized fluorinated pentacene (Pn) molecule as single molecule probes of intermolecular interactions and of the nanoscale environment in blends containing donor and acceptor molecules. Single Pn donor (D) molecules …

Structural Mrsa Resistance Through Carbon-Infiltrated Carbon Nanotube Coating Of External Fixator Pins, Jaclyn Larsen, Stephanie Morco, Brian Jensen, Anton Bowden

Biomedical Engineering Western Regional Conference

No abstract provided.

Effects Of Exposure To Quantum Dots In The External And Internal Environments Of Organisms, Kenton Layne Leigh

Student Theses and Dissertations

The use of nanotechnology in research and consumer products is increasing, but there are few studies regarding the safety of nanoparticles (NPs). NPs’ small size and increased surface area allow for unique physical and chemical properties not seen in bulk counterparts of the same material. Thus, NP interactions within environmental and biological matrices are not well understood. Specifically, quantum dots (QDs) have garnered increased attention due to their superior optical properties. However, little research on the effects of QDs on the environment is available. The studies described herein provide data regarding interactions of QDs in aquatic and terrestrial environments using …

Thermal Transport At The Nanoscale: A Fourier's Law Vs. Phonon Boltzmann Equation Study, Jan Kaiser, T. Feng, Jesse Maassen, X. Wang, X. Ruan, Mark S. Lundstrom

Other Nanotechnology Publications

Steady-state thermal transport in nanostructures with dimensions comparable to the phonon mean-free-path is examined. Both the case of contacts at different temperatures with no internal heat generation and contacts at the same temperature with internal heat generation are considered. Fourier’s Law results are compared to finite volume method solutions of the phonon Boltzmann equation in the gray approximation. When the boundary conditions are properly specified, results obtained using Fourier’s Law without modifying the bulk thermal conductivity are in essentially exact quantitative agreement with the phonon Boltzmann equation in the ballistic and diffusive limits. The errors between these two limits are …

Dirichlet Process Gaussian Mixture Models For Real-Time Monitoring And Their Application To Chemical Mechanical Planarization, Jia (Peter) Liu, Omer F. Beyca, Prahalad K. Rao, Zhenyu (James) Kong, Satish T. S. Bukkapatnam

Department of Mechanical and Materials Engineering: Faculty Publications

The goal of this work is to use sensor data for online detection and identification of process anomalies (faults). In pursuit of this goal, we propose Dirichlet process Gaussian mixture (DPGM) models. The proposed DPGM models have two novel outcomes: 1) DP-based statistical process control (SPC) chart for anomaly detection and 2) unsupervised recurrent hierarchical DP clustering model for identification of specific process anomalies. The presented DPGM models are validated using numerical simulation studies as well as wireless vibration signals acquired from an experimental semiconductor chemical mechanical planarization (CMP) test bed. Through these numerically simulated and experimental sensor data, we …

Fluorescence Lifetime Imaging And Spectroscopy Aided Tracking Of Zno And Cds:Mn/Zns/ N-Acetyl Cysteine (Nac) Quantum Dots In Citrus Plants, Torus Washington

Electronic Theses and Dissertations

In this thesis, we present an efficacious way of tracking nanoparticle movement in plant tissue through the use of fluorescence lifetime imaging (FLIM) and spectroscopy as well as a review of nanoparticle uptake in plants and the proposed mechanisms governing them. Given the increasing number of nanomaterials in agriculture and society as a whole, proper imaging tools and proactive measures must be taken to track nanoparticle movement in plant tissues and create infrastructure and products to keep things sustainable and safe. Herein we report a ZnO comparable nanoparticle— a CdS:Mn/ZnS/ N-acetyl cysteine (NAC) quantum dot— which boasts longer lifetimes and …

High Power Continuous Wave Quantum Cascade Lasers With Increased Ridge Width, Ankesh Todi

Electronic Theses and Dissertations

Quantum Cascade Lasers have recently gained considerable attention for their capability to emit infrared radiation in a broad infrared spectral region, very compact dimensions, and high optical power/efficiency. Increasing continuous wave optical power is one of the main research directions in the field. A straightforward approach to increasing optical power in the pulsed regime is to increase number of stages in the cascade structure. However, due to a low active region thermal conductivity, the increase in number of stages leads to active region overheating in continuous wave operation. In this work, an alternative approach to power scaling with device dimensions …

Freestanding Holey Thin Films For Renewable Energy Storage, Kyle Marcus

Electronic Theses and Dissertations

The rapid advancement of portable and wearable technologies has challenged research to improve upon current renewable battery energy storage systems. By using nanotechnology, it is now possible to access more of the energy storage theoretical values that have been unattainable thus far. We have developed a method to create freestanding holey thin films through combinations of electrochemical and chemical vapor deposition (CVD) techniques to be used in renewable energy storage systems. Freestanding thin films promote excellent contact between the residual conductive framework and any functionalized active component specific to the designed material. Without requiring any other additives, the as-prepared freestanding …

Efficient Planar Heterojunction Perovskite Solar Cells With Li-Doped Compact Tio2 Layer, Detao Liu, Shibin Li, Peng Zhang, Yafei Wang, Rui Zhang, Hojjatollah Sarvari, Feng Wang, Jiang Wu, Zhiming Wang, Zhi Chen

Electrical and Computer Engineering Faculty Publications

Perovskite solar cells (PSCs) have been developed rapidly in recent time, and efficient planar PSCs are regarded as the most promising alternative to the Si solar cells. In this study, we demonstrated that Li-doping of compact TiO₂ can reduce the density of electron traps and increase the conductivity of the electron transport layer (ETL) of PSCs. Due to the improved electronic property of ETL, the Li-doped compact TiO₂ based planar heterojunction PSCs exhibit negligible hysteretic J-V behavior. Comparing with the undoped compact TiO₂ based PSCs, the power conversion efficiency (PCE) of the Li-doped compact TiO₂ film …