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Nanostructures

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Articles 1 - 17 of 17

Full-Text Articles in Nanoscience and Nanotechnology

Glucose Level Estimation Based On Invasive Electrochemical, And Non-Invasive Optical Sensing Methods, Sanghamitra Mandal May 2018

Glucose Level Estimation Based On Invasive Electrochemical, And Non-Invasive Optical Sensing Methods, Sanghamitra Mandal

Theses and Dissertations

The purpose of this research is to design and fabricate sensors for glucose detection using inexpensive approaches. My first research approach is the fabrication of an amperometric electrochemical glucose sensor, by exploiting the optical properties of semiconductors and structural properties of nanostructures, to enhance the sensor sensitivity and response time. Enzymatic electrochemical sensors are fabricated using two different mechanisms: (1) the low-temperature hydrothermal synthesis of zinc oxide nanorods, and (2) the rapid metal-assisted chemical etching of silicon (Si) to synthesize Si nanowires. The concept of gold nano-electrode ensembles is then employed to the sensors in order to boost the current ...


Three-Dimensional Nanomaterials For Supercapacitor Applications: From Metal Oxides To Metal Phosphides, Zhi Zheng Dec 2017

Three-Dimensional Nanomaterials For Supercapacitor Applications: From Metal Oxides To Metal Phosphides, Zhi Zheng

University of New Orleans Theses and Dissertations

Over the past few years, energy storage devices have received tremendous interest due to the increasing demand for sustainable and renewable energy in modern society. Supercapacitors are considered as one of the most promising energy storage devices because of their high power density and long cycle life. However, low energy density remains as the main shortcoming for supercapacitors. The overall performance of supercapacitors is predominantly determined by the characteristics of the electrodes. Specifically, constructing nanostructured electrode material has been proven as an efficient way to improve the performance by providing large surface area and short ionic and electronic diffusion paths ...


Generalized Ellipsometry On Complex Nanostructures And Low-Symmetry Materials, Alyssa Mock Dec 2017

Generalized Ellipsometry On Complex Nanostructures And Low-Symmetry Materials, Alyssa Mock

Theses, Dissertations, and Student Research from Electrical & Computer Engineering

In this thesis, complex anisotropic materials are investigated and characterized by generalized ellipsometry. In recent years, anisotropic materials have gained considerable interest for novel applications in electronic and optoelectronic devices, mostly due to unique properties that originate from reduced crystal symmetry. Examples include white solid-state lighting devices which have become ubiquitous just recently, and the emergence of high-power, high-voltage electronic transistors and switches in all-electric vehicles. The incorporation of single crystalline material with low crystal symmetry into novel device structures requires reconsideration of existing optical characterization approaches. Here, the generalized ellipsometry concept is extended to include applications for materials with ...


Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix Dec 2016

Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix

Theses and Dissertations

As is commonly known, the world is full of technological wonders, where a multitude of electronic devices and instruments continuously help push the boundaries of scientific knowledge and discovery. These new devices and instruments of science must be utilized at peak efficiency in order to benefit humanity with the most advanced scientific knowledge. In order to attain this level of efficiency, the materials which make up these electronics, or possibly more important, the fundamental characteristics of these materials, must be fully understood. The following research attempted to uncover the properties and characteristics of a selected family of materials. Herein, zinc ...


Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa Nov 2016

Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa

Graduate Theses and Dissertations

Multifunctional nanocomposites are promising for a variety of applications ranging from microwave devices to biomedicine. High demand exists for magnetically tunable nanocomposite materials. My thesis focuses on synthesis and characterization of novel nanomaterials such as polymer nanocomposites (PNCs) and multi-walled carbon nanotubes (MWCNTs) with magnetic nanoparticle (NP) fillers.

Magnetite (Fe3O4) and cobalt ferrite (CoFe2O4) NPs with controlled shape, size, and crystallinity were successfully synthesized and used as PNC fillers in a commercial polymer provided by the Rogers Corporation and poly(vinylidene fluoride). Magnetic and microwave experiments were conducted under frequencies of 1-6 GHz in the presence of ...


Metal-Organic Hybrid Nanocomposites For Energy Harvesting Applications, Thulitha Madawa Abeywickrama Oct 2016

Metal-Organic Hybrid Nanocomposites For Energy Harvesting Applications, Thulitha Madawa Abeywickrama

Masters Theses & Specialist Projects

Various synthetic methods have been developed to produce metal nanostructures including copper and iron nanostructures. Modification of nanoparticle surface to enhance their characteristic properties through surface functionalization with organic ligands ranging from small molecules to polymeric materials including organic semiconducting polymers is a key interest in nanoscience. However, most of the synthetic methods developed in the past depend widely on non-aqueous solvents, toxic reducing agents, and high temperature and high-pressure conditions. Therefore, to produce metal nanostructures and their nanocomposites with a simpler and greener method is indeed necessary and desirable for their nano-scale applications. Hence the objective of this thesis ...


Development Of Micro-/Nano-Architectures For Intracellular Sensing Platform, Ryan M. Preston, Dae Seung Wie, Chi Hwan Lee Aug 2016

Development Of Micro-/Nano-Architectures For Intracellular Sensing Platform, Ryan M. Preston, Dae Seung Wie, Chi Hwan Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently available nanotechnologies are capable of creating various nanostructures in controlled dimensions such as particles (0D), wires (1D), membranes (2D), and cubes (3D) by exploiting “top-down” or “bottom-up” methods. However, there exist limitations to systematically construct hierarchical nanostructures with geometric complexities. This study is focused on developing a novel nanofabrication strategy that can rationally produce a set of hierarchical nanostructures configured with precisely engineered facets, tip shapes, and tectonic motifs. We aim to identify a collection of optimal materials, array layouts, basic components, and nanofabrication techniques for the production of hierarchical nanostructures by exploiting device-grade semiconducting silicon materials. To accomplish ...


Collaborative Research: A Nanostructure Sensor For Measuring Dissolved Iron And Copper Concentrations In Coastal And Offshore Seawater, Mark Wells, Carl Tripp Apr 2015

Collaborative Research: A Nanostructure Sensor For Measuring Dissolved Iron And Copper Concentrations In Coastal And Offshore Seawater, Mark Wells, Carl Tripp

University of Maine Office of Research Administration: Grant Reports

Iron and Copper serve as key co-constituents for numerous enzymes in a wide range of biological systems, and their elevated or impoverished levels in aqueous systems have dramatic consequences at organismal, ecosystem, and human health scales. Over the last decade these effects have increasingly been recognized to be important in ocean systems. Identifying sites and times where these metals cause negative environmental outcomes is greatly hampered by their comparatively sparse datasets. This problem is a direct consequence of the analytical challenge of obtaining accurate Fe and Cu determinations in saline waters at very low (trace) concentrations, and the limitations of ...


Multiscale Study Of Batio3 Nanostructures And Nanocomposites, Lydie Louis Louis Aug 2013

Multiscale Study Of Batio3 Nanostructures And Nanocomposites, Lydie Louis Louis

Theses and Dissertations

Advancements in integrated nanoelectronics will continue to require the use of unique materials or systems of materials with diverse functionalities in increasingly confined spaces.

Hence, research on finite-dimensional systems strive to unearth and expand the knowledge of fundamental physical properties in certain key materials which exhibit numerous concurrent and exploitable functions.

Correspondingly, ferroelectric nanostructures, which particularly display a plethora of complex phenomena, prevalent in countless fields of research, are noteworthy candidates. Presently, however, the assimilation of zero-(0D) and one-dimensional (1D) ferroelectric into micro- or nano-electronics has been lagging, in part due to a lack of applied and fundamental studies ...


Lanthanum Halide Nanoparticle Scintillators For Nuclear Radiation Detection, Paul Guss, Ronald Guise, Ding Yuan, Sanjoy Mukhopadhyay, Robert O’Brien, Daniel Robert Lowe, Zhitao Kang, Hisham Menkara, Vivek V. Nagarkar Jan 2013

Lanthanum Halide Nanoparticle Scintillators For Nuclear Radiation Detection, Paul Guss, Ronald Guise, Ding Yuan, Sanjoy Mukhopadhyay, Robert O’Brien, Daniel Robert Lowe, Zhitao Kang, Hisham Menkara, Vivek V. Nagarkar

Mechanical Engineering Faculty Publications

Nanoparticles with sizesscintillators, in order to determine the viability of using scintillators employing nanostructured lanthanum trifluoride. Preliminary results of this investigation are consistent with the idea that these materials have an intrinsic response to nuclear radiation that may be correlated to the energy of the incident radiation.


Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet Dokmeci Jun 2011

Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet Dokmeci

Sinan Müftü

Carbon nanotube networks are an emerging conductive nanomaterial with applications including thin film transistors, interconnects, and sensors. In this letter, we demonstrate the fabrication of single-walled carbon nanotube (SWNT) networks on a flexible polymer substrate and then provide encapsulation utilizing a thin parylene-C layer. The encapsulated SWNT network was subjected to tensile tests while its electrical resistance was monitored. Tests showed a linear-elastic response up to a strain value of 2.8% and nearly linear change in electrical resistance in the 0%–2% strain range. The networks’ electrical resistance was monitored during load-unload tests of up to 100 cycles and ...


Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci May 2011

Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci

Yung Joon Jung

Carbon nanotube networks are an emerging conductive nanomaterial with applications including thin film transistors, interconnects, and sensors. In this letter, we demonstrate the fabrication of single-walled carbon nanotube (SWNT) networks on a flexible polymer substrate and then provide encapsulation utilizing a thin parylene-C layer. The encapsulated SWNT network was subjected to tensile tests while its electrical resistance was monitored. Tests showed a linear-elastic response up to a strain value of 2.8% and nearly linear change in electrical resistance in the 0%–2% strain range. The networks’ electrical resistance was monitored during load-unload tests of up to 100 cycles and ...


Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci May 2011

Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci

Mehmet R. Dokmeci

Carbon nanotube networks are an emerging conductive nanomaterial with applications including thin film transistors, interconnects, and sensors. In this letter, we demonstrate the fabrication of single-walled carbon nanotube (SWNT) networks on a flexible polymer substrate and then provide encapsulation utilizing a thin parylene-C layer. The encapsulated SWNT network was subjected to tensile tests while its electrical resistance was monitored. Tests showed a linear-elastic response up to a strain value of 2.8% and nearly linear change in electrical resistance in the 0%–2% strain range. The networks’ electrical resistance was monitored during load-unload tests of up to 100 cycles and ...


Generalized Ellipsometry On Sculptured Thin Films Made By Glancing Angle Deposition, Daniel Schmidt Dec 2010

Generalized Ellipsometry On Sculptured Thin Films Made By Glancing Angle Deposition, Daniel Schmidt

Theses, Dissertations, and Student Research from Electrical & Computer Engineering

In this thesis, physical properties of highly optically and magnetically anisotropic metal sculptured thin films made by glancing angle deposition are presented. Predominantly, the determination of optical and magneto-optical properties with spectroscopic generalized Mueller matrix ellipsometry and homogenization approaches is discussed. Nomenclatures are proposed to unambiguously identify the sculptured thin film geometry.

Generalized ellipsometry, a non-destructive optical characterization technique, is employed to determine geometrical structure and anisotropic dielectric properties of highly spatially coherent three-dimensionally nanostructured thin films in the spectral range from 400 to 1700 nm. The analysis of metal slanted columnar thin films (F1-STFs) deposited at glancing angle (θ ...


Giant Raman Enhancement On Nanoporous Gold Film By Conjugating With Nanoparticles For Single-Molecule Detection, Lihua Qian, Biswajit Das, Yan Li, Zhilin Yang Jan 2010

Giant Raman Enhancement On Nanoporous Gold Film By Conjugating With Nanoparticles For Single-Molecule Detection, Lihua Qian, Biswajit Das, Yan Li, Zhilin Yang

Electrical and Computer Engineering Faculty Publications

Hot spots have the contradictively geometrical requirements for both the narrowest interstices to provide strong near-field coupling, and sufficient space to allow entrance of the analytes. Herein, a two-step method is employed to create hot spots within hybrid nanostructures, which consist of self-supported nanoporous gold films with the absorbed probes and subsequent nanoparticle conjugates without surface agents or mechanical motion. The molecules confined into 1 nm interstice exhibit 2.9 × 107 times enhancement in Raman scattering compared to pure nanoporous gold. Giant enhancement primarily results from strong near-field coupling between nanopore and nanoparticle, which is theoretically confirmed by finite-difference ...


Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao Jan 2009

Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao

UNLV Theses, Dissertations, Professional Papers, and Capstones

Currently, one-dimensional (1-D) nanostructures have drawn much interest because of their potential applications for nanoscale optoelectronic devices. Self-assembly (SA) based on π-conjugated systems through various intermolecular interactions has been widely used to produce 1-D nanostructure. Morphology of the assembled structures can be modified by incorporating substituents, which provide additional secondary interactions. Meanwhile, those substituents also influence the electronic properties of the molecules. Previous studies have made little effort to systematically study subsistent effects on both electronic and SA properties.

The primary objective of this research is to generate controllable 1-D structures through SA, and to provide a fundamental understanding of ...


Cofe2o4 Nanostructures With High Coercivity, J S. Jung, J H. Lim, K H. Choi, S L. Oh, Y R. Kim, S H. Lee, D A. Smith, K L. Stokes, L Malkinski, C J. O'Connor Jan 2005

Cofe2o4 Nanostructures With High Coercivity, J S. Jung, J H. Lim, K H. Choi, S L. Oh, Y R. Kim, S H. Lee, D A. Smith, K L. Stokes, L Malkinski, C J. O'Connor

Physics Faculty Publications

Nanometer-sized ferrite magnetic materials are the subject of intense research interest due to their potential applications in high-density magnetic information storage. One of the most explored ferrite materials is the cobalt ferrite (CoFe2O4).. We have synthesized cobalt ferrite nanowires using cobalt ferrite nanoparticles in a porous anodic alumina template (AAT). The process of embedding ferrimagnetic particles into the pores was assisted by the magnetic field of a permanent magnet placed in vacuum directly under the substrate. Particles synthesized in the template were subsequently annealed at 600 °C for 2 h in Ar gas forming arrays of cobalt ferrite nanowires inside ...