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Graphene

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Full-Text Articles in Engineering

Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight Aug 2020

Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight

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

In this dissertation, optical Hall effect (OHE) measurements are used to determine the free charge carrier properties of important two-dimensional materials and monoclinic oxides. Two-dimensional material systems have proven useful in high-frequency electronic devices due to their unique properties, such as high mobility, which arise from their two-dimensional nature. Monoclinic oxides exhibit many desirable characteristics, for example low-crystal symmetry which could lead to anisotropic carrier properties. Here, single-crystal monoclinic gallium oxide, an AlInN/GaN-based high-electron-mobility transistor (HEMT) structure, and epitaxial graphene are studied as examples. To characterize these material systems, the OHE measurement technique is employed. The OHE is a ...


Tunable Compact Thz Devices Based On Graphene And Other 2d Material Metasurfaces, Tianjing Guo Jul 2020

Tunable Compact Thz Devices Based On Graphene And Other 2d Material Metasurfaces, Tianjing Guo

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

Since the isolation of graphene in 2004, a large amount of research has been directed at 2D materials and their applications due to their unique characteristics. Compared with the noble metal plasmons in the visible and near-infrared frequencies, graphene can support surface plasmons in the lower frequencies of terahertz (THz) and midinfrared. Especially, the surface conductivity of graphene can be tuned by either chemical doping or electrostatic gating. As a result, the idea of designing graphene metasurfaces is attractive because of its ultra-broadband response and tunability.

It has been demonstrated theoretically and experimentally that the third-order nonlinearity of graphene at ...


Thermal Characterization Of Graphene/Polyethylene Nanocomposites, Ahmed Z. A. Abuibaid Jun 2020

Thermal Characterization Of Graphene/Polyethylene Nanocomposites, Ahmed Z. A. Abuibaid

Chemical and Petroleum Engineering Theses

Practically, almost all polymers are solidified from the melts for product-forming purposes. Therefore, the evolution of solid structure (crystallization behavior) from their molten form has prime importance in manufacturing high performance materials. Polyethylene (PE) is one of the most commonly used semicrystalline polymers all over the world. In this thesis, nanocomposites of PE with thermal reduced graphene (TRG) (PE/TRG) were prepared via solvent blending and the crystallization of PE has been investigated using a differential scanning calorimeter (DSC). The nanocomposites were crystallized from the melts under both isothermal and dynamic conditions, and evolution of crystal formation is studied using ...


Study Of The Detection And The Emission Of Thz Waves In Mos₂Material, Ayah Masoud Ass’Ad Hijazi May 2020

Study Of The Detection And The Emission Of Thz Waves In Mos₂Material, Ayah Masoud Ass’Ad Hijazi

Electrical Engineering Theses

Terahertz (THz) technology is receiving a wide interest nowadays, developing more researches worldwide to emerge new devices based on the THz regime and overcoming the challenge of the remarkable THz-gap. This thesis is concerned with studying and developing new emerging materials with new structures in terms of THz waves. The main objective of this thesis is to examine how the MoS₂ material in nanoribbons structure detect and emit THz waves theoretically and experimentally in contrast to Graphene nanoribbon material. The theoretical model was used alongside the experimental setup to fully understand the behavior of the materials and to have a ...


Enhancing The Conductivity Of Cell-Laden Alginate Microfibers With Aqueous Graphene For Neural Applications, Marilyn C. Mcnamara, Amir Ehsan Niaraki-Asli, Jingshuai Guo, Jasmin Okuzono, Reza Montazami, Nicole N. Hashemi Mar 2020

Enhancing The Conductivity Of Cell-Laden Alginate Microfibers With Aqueous Graphene For Neural Applications, Marilyn C. Mcnamara, Amir Ehsan Niaraki-Asli, Jingshuai Guo, Jasmin Okuzono, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Microfluidically manufacturing graphene-alginate microfibers create possibilities for encapsulating rat neural cells within conductive 3D tissue scaffolding to enable the creation of real-time 3D sensing arrays with high physiological relavancy. Cells are encapsulated using the biopolymer alginate, which is combined with graphene to create a cell-containing hydrogel with increased electrical conductivity. Resulting novel alginate-graphene microfibers showed a 2.5-fold increase over pure alginate microfibers, but did not show significant differences in size and porosity. Cells encapsulated within the microfibers survive for up to 8 days, and maintain ~20% live cells over that duration. The biocompatible aqueous graphene suspension used in this ...


Corrosion-Induced Mass Loss Measurement Under Strain Conditions Through Gr/Agnw-Based, Fe-C Coated Lpfg Sensors, Chuanrui Guo, Liang Fan, Genda Chen Mar 2020

Corrosion-Induced Mass Loss Measurement Under Strain Conditions Through Gr/Agnw-Based, Fe-C Coated Lpfg Sensors, Chuanrui Guo, Liang Fan, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, graphene/silver nanowire (Gr/AgNW)-based, Fe-C coated long period fiber gratings (LPFG) sensors were tested up to 72 hours in 3.5 w.t% NaCl solution for corrosion-induced mass loss measurement under four strain levels: 0, 500, 1000 and 1500 µ∈. The crack and interfacial bonding behaviors of laminate Fe-C and Gr/AgNW layer structures were characterized using Scanning Electron Microscopy (SEM) and electrical resistance measurement. Both optical transmission spectra and electrical impedance spectroscopy (EIS) data were simultaneously measured from each sensor. Under increasing strains, transverse cracks appeared first and were followed by longitudinal cracks on ...


Fabrication Of 2d And 3d High-Resolution Binder-Free Graphene Circuits Using A Microfluidic Approach For Sensor Applications, Metin Uz, Matthew T. Lentner, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, John Hondred, Eric Mach, Jonathan C. Claussen, Surya K. Mallapragada Feb 2020

Fabrication Of 2d And 3d High-Resolution Binder-Free Graphene Circuits Using A Microfluidic Approach For Sensor Applications, Metin Uz, Matthew T. Lentner, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, John Hondred, Eric Mach, Jonathan C. Claussen, Surya K. Mallapragada

Chemical and Biological Engineering Publications

In this study, a simple microfluidic method, which can be universally applied to different rigid or flexible substrates, was developed to fabricate high-resolution, conductive, 2D and 3D microstructured graphene-based electronic circuits. The method involves controlled and selective filling of microchannels on substrate surfaces with a conductive binder-free graphene nanoplatelets (GNP) solution. The ethanol-thermal reaction of GNP solution at low temperatures (~75 °C) prior to microchannel filling (pre-heating) further reduces GNP, enhances conductivity, reduces sheet resistance (~0.05 kΩ sq-1), enables room temperature fabrication and eliminates harsh post-processing, which makes this fabrication technique compatible with degradable substrates. This method can also ...


A Preliminary Study Of A Graphene Fractal Sierpinski Antenna, Alberto Boretti, Lorenzo Rosa, Jonathan Blackledge, Stefania Castelletto Jan 2020

A Preliminary Study Of A Graphene Fractal Sierpinski Antenna, Alberto Boretti, Lorenzo Rosa, Jonathan Blackledge, Stefania Castelletto

Conference papers

We provide a preliminary study of a Graphene fractal antenna operating at THz frequencies with the opportunity to modulate the emission. There are a number of advantages of the fractal design, namely multiband/wideband ability, and, a smaller, lighter and simpler configuration for higher gain, that can benefit from the coupling with Graphene, the thinnest and strongest of materials exhibiting very high electrical conductivity and tunability. This paper proposes a conceptual background for the study and presents some preliminary results on the electromagnetic emission simulations undertaken


Dealloyed Porous Gold Anchored By: In Situ Generated Graphene Sheets As High Activity Catalyst For Methanol Electro-Oxidation Reaction, Hui Xu, Shuai Liu, Xiaoliang Pu, Kechang Shen, Laichang Zhang, Xiaoguang Wang, Jingyu Qin, Weimin Wang Jan 2020

Dealloyed Porous Gold Anchored By: In Situ Generated Graphene Sheets As High Activity Catalyst For Methanol Electro-Oxidation Reaction, Hui Xu, Shuai Liu, Xiaoliang Pu, Kechang Shen, Laichang Zhang, Xiaoguang Wang, Jingyu Qin, Weimin Wang

ECU Publications Post 2013

A novel one-step method to prepare the nanocomposites of reduced graphene oxide (RGO)/nanoporous gold (NPG) is realized by chemically dealloying an Al2Au precursor. The RGO nanosheets anchored on the surface of NPG have a cicada wing like shape and act as both conductive agent and buffer layer to improve the catalytic ability of NPG for methanol electro-oxidation reaction (MOR). This improvement can also be ascribed to the microstructure change of NPG in dealloying with RGO. This work inspires a facile and economic method to prepare the NPG based catalyst for MOR.


Confning Tio2 Nanotubes In Pecvd‑Enabled Graphene Capsules Toward Ultrafast K‑Ion Storage: In Situ Tem/Xrd Study And Dft Analysis, Jingsheng Cai, Ran Cai, Zhongti Sun, Xiangguo Wang, Nan Wei, Feng Xu, Yuanlong Shao, Peng Gao, Shi Xue Dou, Jingyu Sun Jan 2020

Confning Tio2 Nanotubes In Pecvd‑Enabled Graphene Capsules Toward Ultrafast K‑Ion Storage: In Situ Tem/Xrd Study And Dft Analysis, Jingsheng Cai, Ran Cai, Zhongti Sun, Xiangguo Wang, Nan Wei, Feng Xu, Yuanlong Shao, Peng Gao, Shi Xue Dou, Jingyu Sun

Australian Institute for Innovative Materials - Papers

© 2020, © 2020, The Author(s). Titanium dioxide (TiO2) has gained burgeoning attention for potassium-ion storage because of its large theoretical capacity, wide availability, and environmental benignity. Nevertheless, the inherently poor conductivity gives rise to its sluggish reaction kinetics and inferior rate capability. Here, we report the direct graphene growth over TiO2 nanotubes by virtue of chemical vapor deposition. Such conformal graphene coatings effectively enhance the conductive environment and well accommodate the volume change of TiO2 upon potassiation/depotassiation. When paired with an activated carbon cathode, the graphene-armored TiO2 nanotubes allow the potassium-ion hybrid capacitor full cells to harvest an energy ...


Microwave-Assisted Synthesis Of Graphene Supported Hexagonal Magnetite For Applications In Catalysis, Hany A. Elazab, M. A. Radwan, M. A. Sadek Oct 2019

Microwave-Assisted Synthesis Of Graphene Supported Hexagonal Magnetite For Applications In Catalysis, Hany A. Elazab, M. A. Radwan, M. A. Sadek

Chemical Engineering

Herein, we report a rapid one-step synthetic method using microwave irradiation for growing magnetite nanocrystals on reduced graphene oxide sheets. This developed strategy allows decorating graphene sheets with magnetite nanocrystals of well-defined morphology as cubes using microwave-driven reduction of iron chloride using hydrazine hydrate as a reducing agent. The size and shape control was achieved via fine-tuning of the reaction conditions. The obtained results demonstrate the applicability of this microwave synthetic approach to control the morphology of the magnetite nanocrystals anchored on graphene sheets. Moreover, graphene sheets will enhance the nucleation and growth of magnetite nanoplates anchored on graphene. This ...


Pd Nanoparticles Supported On Copper Oxide Prepared Via Microwave – Assisted Synthesis: An Efficient Catalyst For Suzuki Cross-Coupling, Hany A. Elazab Dr Sep 2019

Pd Nanoparticles Supported On Copper Oxide Prepared Via Microwave – Assisted Synthesis: An Efficient Catalyst For Suzuki Cross-Coupling, Hany A. Elazab Dr

Chemical Engineering

We report here a scientific investigation of a simple and versatile synthetic rote for the synthesis of palladium nanoparticles decorated with copper oxideand supported on reduced Graphene oxide (rGO) as a highly active catalyst usedfor Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (7000) and turnover frequency of 85000 h-1. Pd-CuO nanoparticles supported on reduced Graphene oxide nanosheets (Pd-CuO/rGO) exhibited an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction ...


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson Sep 2019

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


Facile Synthesis Of Reduced Graphene Oxide-Supported Pd/Cuo Nano-Particles As An Efficient Catalyst For Cross-Coupling Reactions, Hany A. Elazab Dr Sep 2019

Facile Synthesis Of Reduced Graphene Oxide-Supported Pd/Cuo Nano-Particles As An Efficient Catalyst For Cross-Coupling Reactions, Hany A. Elazab Dr

Chemical Engineering

The present communication reports a scientific investigation of a simple and versatile synthetic route for the synthesis of palladium nanoparticles decorated with copper oxide and supported on reduced graphene oxide (rGO). They are used as a highly active catalyst of Suzuki, Heck, and Sonogashira cross coupling reactions with a remarkable turnover number of 7000 and a turnover frequency of 85000 h-1. The Pd-CuO nanoparticles supported on reduced graphene oxide nanosheets (Pd-CuO/rGO) exhibit an outstanding performance through a high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method is used to prepare this efficient catalyst using microwave ...


Graphene Channels Interfaced With Distributed Quantum Dots, Xin Miao Aug 2019

Graphene Channels Interfaced With Distributed Quantum Dots, Xin Miao

Dissertations

Previous research has elucidated the remarkable electrical and optical characteristics of graphene and pointed to the various applications of graphene-based devices. One of such applications is electro-optical graphene-based elements. In this work, the optoelectronic properties of field-effect transistors are explored. These are composed of surface graphene guides, which are interfaced with an array of individual semiconductor quantum dots. The graphene guide also serves as a channel for the field-effect transistor (FET) while the dots provide for fluorescence markers. They may be placed either within the capacitor formed between the graphene and the gate electrode, or on top of the graphene ...


Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin Jul 2019

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti3C2Tx and Ti2CTx) with a SiO2 coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account surface ...


Thermal Characterization Of Graphene/Polyethylene Nanocomposites, Ahmed Z. A. Abuibaid Jun 2019

Thermal Characterization Of Graphene/Polyethylene Nanocomposites, Ahmed Z. A. Abuibaid

Chemical and Petroleum Engineering Theses

Practically, almost all polymers are solidified from the melts for product-forming purposes. Therefore, the evolution of solid structure (crystallization behavior) from their molten form has prime importance in manufacturing high performance materials. Polyethylene (PE) is one of the most commonly used semi crystalline polymers all over the world. In this thesis, nanocomposites of PE with thermal reduced graphene (TRG) (PE/TRG) were prepared via solvent blending and the crystallization of PE has been investigated using a differential scanning calorimeter (DSC). The nanocomposites were crystallized from the melts under both isothermal and dynamic conditions, and evolution of crystal formation is studied ...


Modelling Palladium Decorated Graphene Using Density Functional Theory To Analyze Hydrogen Sensing Application, Sameer Kulkarni May 2019

Modelling Palladium Decorated Graphene Using Density Functional Theory To Analyze Hydrogen Sensing Application, Sameer Kulkarni

Mechanical Engineering Undergraduate Honors Theses

Graphene is an exciting new material with many promising applications. One such application of graphene is gas sensing, when adsorbed with transition metals, notably Palladium. Therefore, it is of paramount importance to have appropriate ab initio calculations to calculate the various properties of graphene under different adsorbates and gasses. The first step in these calculations is to have a functioning base Density Functional Theory (DFT) model of pristine graphene decorated with Palladium. The computational methods described in this paper has yielded results for pristine graphene that have been confirmed many times in previous experimental and theoretical studies. Future work needs ...


Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon May 2019

Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon

Senior Theses

Two-dimensional materials exhibit properties unlike anything else seen in conventional substances. Electrons in these materials are confined to move only in the plane. In order to explore the effects of these materials, we have built apparatus and refined procedures with which to create two-dimensional structures. Two-dimensional devices have been made using exfoliated graphene and placed on gold contacts. Their topography has been observed using Atomic Force Microscopy (AFM) confirming samples with monolayer, bilayer, and twisted bilayer structure. Relative work functions of each have been measured using Kelvin Probe Force Microscopy (KPFM) showing that twisted bilayer graphene has a surface potential ...


Evaluating The Scalability Of The Sonication Method Of Graphene Oxide Synthesis, Evan Dexter May 2019

Evaluating The Scalability Of The Sonication Method Of Graphene Oxide Synthesis, Evan Dexter

Honors Program Projects

Graphene is a new material that was first isolated in 2004, and consists of one to a few atomic layers of carbon in a lattice sheet structure. Graphene has high tensile strength, high surface area, very low electrical resistance, and various other special properties that make it an excellent material for use in emerging technologies in the categories of electrical components, energy systems, and high strength applications. The production scale of graphene sheets and its variations is currently limited to laboratory use, with increasing research being conducted toward the development of manufacturing techniques of the material. We conducted experiments to ...


Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu May 2019

Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu

Theses and Dissertations

Recently, various groups have demonstrated nano-scale engineering of nanostructures for optical to infrared wavelength plasmonic applications. Most fabrication technique processes, especially those using noble metals, requires an adhesion layer. Previously proposed theoretical work to support experimental measurement often neglect the effect of the adhesion layers. The first finding of this work focuses on the impact of the adhesion layer on nanoparticle plasmonic properties. Gold nanodisks with a titanium adhesion layer are investigated by calculating the scattering, absorption, and extinction cross-section with numerical simulations using a finite difference time domain (FDTD) method. I demonstrate that a gold nanodisk with an adhesive ...


Evaluating The Scalability Of Graphene Synthesis, Evan Dexter Apr 2019

Evaluating The Scalability Of Graphene Synthesis, Evan Dexter

Scholar Week 2016 - present

Graphene is a new material, first isolated in 2004, consisting of one to a few atomic layers of carbon in a lattice sheet structure. Graphene has high tensile strength, high surface area, very low electrical resistance, and various other special properties that make it an excellent material for use in emerging technologies in the categories of electrical components, energy systems, and high strength applications. The production scale of graphene sheets and its variations is currently limited to laboratory use, with a great amount of current research going into the development of manufacturing techniques of the material. I conducted experiments to ...


Hydrothermal Synthesis Of Graphene Supported Pd/Fe3o4 Nanoparticles As Efficient Magnetic Catalysts For Suzuki Cross – Coupling, Hany A. Elazab Dr Apr 2019

Hydrothermal Synthesis Of Graphene Supported Pd/Fe3o4 Nanoparticles As Efficient Magnetic Catalysts For Suzuki Cross – Coupling, Hany A. Elazab Dr

Chemical Engineering

This research reports a reproducible, reliable, and efficient method for preparing palladium nanoparticles dispersed on a composite of Fe3O4 and graphene as an active catalyst with high efficiency for being used in Suzuki cross – coupling reactions. Graphene supported Pd/Fe3O4 nanoparticles (Pd/Fe3O4/G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst recyclability was up to nine times without losing its high catalytic activity. The catalyst was prepared using hydrothermal synthesis; the prepared catalyst is magnetic in order to facilitate catalyst separation out of the reaction medium after reaction completion simply through using a strong ...


Shock Compaction Of Graphene Doped Yttria Stabilized Zirconia: An Experimental And Computational Study, Christopher Rueben Johnson Apr 2019

Shock Compaction Of Graphene Doped Yttria Stabilized Zirconia: An Experimental And Computational Study, Christopher Rueben Johnson

Master's Theses (2009 -)

Yttria stabilized zirconia (YSZ) is a broadly used ceramic due to its impeccable hardness and thermal stability. Limitations of the material, however, subsist within its fracture toughness. Literature indicates that shock consolidation may enable production of composite YSZ and graphene mixtures with improved fracture toughness and other material properties while maintaining the material’s nanostructure dimensionality. Therefore, investigation of the compaction phenomena at non-equilibrium states will provide informative results to be used in the fabrication of bulk graphene-YSZ composites. Computational molecular dynamics (MD) simulations and impact experiments are conducted to explore and characterize the dynamic response of the YSZ variants ...


Study Of Charge Carrier Transport In Graphene And Graphite As Two Dimensional And Quasi-Two Dimensional Materials And Their Interfaces, Nalat Sornkhampan Mar 2019

Study Of Charge Carrier Transport In Graphene And Graphite As Two Dimensional And Quasi-Two Dimensional Materials And Their Interfaces, Nalat Sornkhampan

FIU Electronic Theses and Dissertations

Evidence of superconductivity in phosphorous-doped graphite and graphene has been observed at temperatures in the vicinity of 260 K. This evidence includes transport current, magnetic susceptibility, Hall and Nernst measurements. All of these measurements indicate a transition of a type II superconductor without a phase of type I until below the limits of the measurement capabilities.

Vortex states are inferred from periodically repeated steps in the R vs. T characteristics of Highly Oriented Pyrolytic Graphite and exfoliated doped multilayer graphene. The presence of vortices has been confirmed with thermal gradient driven Nernst measurements. Magnetic susceptibility measurements have shown results qualitatively ...


Thermal Transport In Layer-By-Layer Assembled Polycrystalline Graphene Films, David Estrada, Alondra Perez Mar 2019

Thermal Transport In Layer-By-Layer Assembled Polycrystalline Graphene Films, David Estrada, Alondra Perez

Materials Science and Engineering Faculty Publications and Presentations

New technologies are emerging which allow us to manipulate and assemble 2-dimensional (2D) building blocks, such as graphene, into synthetic van der Waals (vdW) solids. Assembly of such vdW solids has enabled novel electronic devices and could lead to control over anisotropic thermal properties through tuning of inter-layer coupling and phonon scattering. Here we report the systematic control of heat flow in graphene-based vdW solids assembled in a layer-by-layer (LBL) fashion. In-plane thermal measurements (between 100 K and 400 K) reveal substrate and grain boundary scattering limit thermal transport in vdW solids composed of one to four transferred layers of ...


Quantifying Thermal Boundary Conductance Of 2d–3d Interfaces, Zlatan Aksamija, Cameron J. Foss Feb 2019

Quantifying Thermal Boundary Conductance Of 2d–3d Interfaces, Zlatan Aksamija, Cameron J. Foss

Zlatan Aksamija

Heat dissipation in next-generation electronics based on two-dimensional (2D) materials is a
critical issue in their development and implementation. A potential bottleneck for heat removal in
2D-based devices is the thermal pathway from the 2D layer into its supporting substrate. The choice
of substrate, its composition and structure, can strongly impact the thermal boundary conductance
(TBC). Here we investigate the temperature-dependent TBC of 42 interfaces formed between a
group of six 2D materials and seven crystalline and amorphous substrates. We use first-principles
density functional perturbation theory to calculate the full phonon dispersion of the 2D layers and
substrates and then ...


Open-Source Automated Chemical Vapor Deposition System For The Production Of Two-Dimensional Nanomaterials, Lizandra Williams-Godwin, Dale Brown, Richard Livingston, Tyler Webb, Lynn Karriem, Elton Graugnard, David Estrada Jan 2019

Open-Source Automated Chemical Vapor Deposition System For The Production Of Two-Dimensional Nanomaterials, Lizandra Williams-Godwin, Dale Brown, Richard Livingston, Tyler Webb, Lynn Karriem, Elton Graugnard, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

The study of two- dimensional (2D) materials is a rapidly growing area within nanomaterials research. However, the high equipment costs, which include the processing systems necessary for creating these materials, can be a barrier to entry for some researchers interested in studying these novel materials. Such process systems include those used for chemical vapor deposition, a preferred method for making these materials. To address this challenge, this article presents the first open-source design for an automated chemical vapor deposition system that can be built for less than a third of the cost for a comparable commercial system. The materials and ...


Design And Rapid Prototyping Of Printed Graphene Electrochemical Biosensors For Sensitive Monitoring Of Pesticide Levels For Agricultural Use, John Hondred Jan 2019

Design And Rapid Prototyping Of Printed Graphene Electrochemical Biosensors For Sensitive Monitoring Of Pesticide Levels For Agricultural Use, John Hondred

Graduate Theses and Dissertations

While the use of pesticides (herbicides and insecticides) are critically important to meet the current and future food demands (increases crop yield by up to 40%), their overuse has shown long-term detrimental impacts on the environment from polluting watersheds used for drinking water to eutrophic “dead zones”. Current pesticide soil measurement methods (chromatography) are costly, require trained technicians, and take days to analyze; thus, farmers are taking an “over-application approach” which is pollution the environment and waterways. A disposable pesticide soil sensor would provide farmers the opportunity of precisely regulating the application of pesticides in an independent and economical fashion ...


Adaptive Hybrid Structures To Enhance Graphene-Based Sensors For Detecting Moisture In Corn Plants, Matthew Davis Jan 2019

Adaptive Hybrid Structures To Enhance Graphene-Based Sensors For Detecting Moisture In Corn Plants, Matthew Davis

Graduate Theses and Dissertations

The utilization of graphene, a two-dimensional structure of carbon atoms, to measure water content in corn plants is presented. Discussed are the structural properties of graphene, fabrication methods, and previous designs by other research groups. This work attempts to design and test a new style of graphene sensor that maintains signal stability while not inhibiting plant growth or health. Specifically, the use of inkjet printing and molds to manufacture the graphene sensor component and the use of a soft polymer for a flexible attachment is examined. Simulations for determining the efficacy of mechanical structures are also analyzed.