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Full-Text Articles in Nanoscience and Nanotechnology

Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada Jul 2019

Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada

Jonathan C. Claussen

In this study, a novel method based on the transfer of graphene patterns from a rigid or flexible substrate onto a polymeric film surface via solvent casting was developed. The method involves the creation of predetermined graphene patterns on the substrate, casting a polymer solution, and directly transferring the graphene patterns from the substrate to the surface of the target polymer film via a peeling-off method. The feature sizes of the graphene patterns on the final film can vary from a few micrometers (as low as 5 µm) to few millimeters range. This process, applied at room temperature, eliminates the ...


Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada Jul 2019

Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada

Surya K. Mallapragada

In this study, a novel method based on the transfer of graphene patterns from a rigid or flexible substrate onto a polymeric film surface via solvent casting was developed. The method involves the creation of predetermined graphene patterns on the substrate, casting a polymer solution, and directly transferring the graphene patterns from the substrate to the surface of the target polymer film via a peeling-off method. The feature sizes of the graphene patterns on the final film can vary from a few micrometers (as low as 5 µm) to few millimeters range. This process, applied at room temperature, eliminates the ...


Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada Jul 2019

Fabrication Of High-Resolution Graphene-Based Flexible Electronics Via Polymer Casting, Metin Uz, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, Matthew T. Lentner, John A. Hondred, Jonathan C. Claussen, Surya K. Mallapragada

Chemical and Biological Engineering Publications

In this study, a novel method based on the transfer of graphene patterns from a rigid or flexible substrate onto a polymeric film surface via solvent casting was developed. The method involves the creation of predetermined graphene patterns on the substrate, casting a polymer solution, and directly transferring the graphene patterns from the substrate to the surface of the target polymer film via a peeling-off method. The feature sizes of the graphene patterns on the final film can vary from a few micrometers (as low as 5 µm) to few millimeters range. This process, applied at room temperature, eliminates the ...


Thin Biobased Transparent Uv-Blocking Coating Enabled By Nanoparticle Self-Assembly, Emily Olson, Yifan Li, Fang-Yi Lin, Ana Miller, Fei Liu, Ayuna Tsyrenova, Devin Palm, Greg W. Curtzwiler, Keith L. Vorst, Eric W. Cochran, Shan Jiang Jun 2019

Thin Biobased Transparent Uv-Blocking Coating Enabled By Nanoparticle Self-Assembly, Emily Olson, Yifan Li, Fang-Yi Lin, Ana Miller, Fei Liu, Ayuna Tsyrenova, Devin Palm, Greg W. Curtzwiler, Keith L. Vorst, Eric W. Cochran, Shan Jiang

Eric W. Cochran

A waterborne, UV-blocking, and visually transparent nanocomposite coating was formulated with ZnO nanoparticles and 2-hydroxyethyl cellulose (HEC). The coating is highly effective (< 5% UV and ~ 65% visible transmittance) and the film thickness (0.2 – 2.5 μm) is ~100 times thinner than the conventional coatings of similar UV-blocking performance. The superior properties are due to the fractal structures of ZnO nanoparticles assembled within the HEC matrix, revealed by scanning electron microscopy (SEM) and small-angle x-ray scattering (SAXS). Changing the binder to 2-hydroxyethyl starch (HES) diminishes the UV-blocking performance, as ZnO nanoparticles form dense globular aggregates, with an aggregation number measured by SAXS three orders of magnitude larger than the HEC coating. Since HEC and HES share the same same chemical compositionrepeating glucose unit in the polymer backbone, it suggests that the conformational characteristics of the binder polymer have a strong influence on the nanoparticle aggregation, which plays a key role in determining the optical performance. Similar structures were achieved with TiO2 nanoparticles. This study not only offers a cost-effective and readily scalable method to fabricate transparent UV-blocking coating, but also demonstrates that the unique fractal aggregation structures in a nanocomposite material can provide high performance and functionality without fully dispersing the nanoparticles.


Transparent Ohmic Contacts For Solution-Processed, Ultrathin Cdte Solar Cells, J. Matthew Kurley, Matthew G. Panthani, Ryan W. Crisp, Sanjini U. Nanayakkara, Gregory F. Pach, Matthew O. Reese, Margaret H. Hudson, Dmitriy S. Dolzhnikov, Vadim Tanygin, Joseph M. Luther, Dmitri V. Talapin Jun 2019

Transparent Ohmic Contacts For Solution-Processed, Ultrathin Cdte Solar Cells, J. Matthew Kurley, Matthew G. Panthani, Ryan W. Crisp, Sanjini U. Nanayakkara, Gregory F. Pach, Matthew O. Reese, Margaret H. Hudson, Dmitriy S. Dolzhnikov, Vadim Tanygin, Joseph M. Luther, Dmitri V. Talapin

Matthew Panthani

Recently, solution-processing became a viable route for depositing CdTe for use in photovoltaics. Ultrathin (∼500 nm) solar cells have been made using colloidal CdTe nanocrystals with efficiencies exceeding 12% power conversion efficiency (PCE) demonstrated by using very simple device stacks. Further progress requires an effective method for extracting charge carriers generated during light harvesting. Here, we explored solution-based methods for creating transparent Ohmic contacts to the solution-deposited CdTe absorber layer and demonstrated molecular and nanocrystal approaches to Ohmic hole-extracting contacts at the ITO/CdTe interface. We used scanning Kelvin probe microscopy to further show how the above approaches improved carrier ...


Thin Biobased Transparent Uv-Blocking Coating Enabled By Nanoparticle Self-Assembly, Emily Olson, Yifan Li, Fang-Yi Lin, Ana Miller, Fei Liu, Ayuna Tsyrenova, Devin Palm, Greg W. Curtzwiler, Keith L. Vorst, Eric W. Cochran, Shan Jiang Jun 2019

Thin Biobased Transparent Uv-Blocking Coating Enabled By Nanoparticle Self-Assembly, Emily Olson, Yifan Li, Fang-Yi Lin, Ana Miller, Fei Liu, Ayuna Tsyrenova, Devin Palm, Greg W. Curtzwiler, Keith L. Vorst, Eric W. Cochran, Shan Jiang

Chemical and Biological Engineering Publications

A waterborne, UV-blocking, and visually transparent nanocomposite coating was formulated with ZnO nanoparticles and 2-hydroxyethyl cellulose (HEC). The coating is highly effective (< 5% UV and ~ 65% visible transmittance) and the film thickness (0.2 – 2.5 μm) is ~100 times thinner than the conventional coatings of similar UV-blocking performance. The superior properties are due to the fractal structures of ZnO nanoparticles assembled within the HEC matrix, revealed by scanning electron microscopy (SEM) and small-angle x-ray scattering (SAXS). Changing the binder to 2-hydroxyethyl starch (HES) diminishes the UV-blocking performance, as ZnO nanoparticles form dense globular aggregates, with an aggregation number measured by SAXS three orders of magnitude larger than the HEC coating. Since HEC and HES share the same same chemical compositionrepeating glucose unit in the polymer backbone, it suggests that the conformational characteristics of the binder polymer have a strong influence on the nanoparticle aggregation, which plays a key role in determining the optical performance. Similar structures were achieved with TiO2 nanoparticles. This study not only offers a cost-effective and readily scalable method to fabricate transparent UV-blocking coating, but also demonstrates that the unique fractal aggregation structures in a nanocomposite material can provide high performance and functionality without fully dispersing the nanoparticles.


Synthesis Of Germanium Nanocrystals From Solid-State Disproportionation Of A Chloride-Derived Germania Glass, Yujie Wang, Utkarsh Ramesh, Charles K. A. Nyamekye, Bradley J. Ryan, Rainie D. Nelson, Abdulla M. Alebri, Umar H. Hamdeh, Atefe Hadi, Emily A. Smith, Matthew G. Panthani Jun 2019

Synthesis Of Germanium Nanocrystals From Solid-State Disproportionation Of A Chloride-Derived Germania Glass, Yujie Wang, Utkarsh Ramesh, Charles K. A. Nyamekye, Bradley J. Ryan, Rainie D. Nelson, Abdulla M. Alebri, Umar H. Hamdeh, Atefe Hadi, Emily A. Smith, Matthew G. Panthani

Matthew Panthani

Germanium nanocrystals (Ge NCs) have potential to be used in several optoelectronic applications such as photodetectors and light-emitting diodes. Here, we report a solid-state route to synthesizing Ge NCs through thermal disproportionation of a germania (GeOX) glass, which was synthesized by hydrolyzing a GeCl2·dioxane complex. The GeOX glass synthesized in this manner was found to have residual Cl content. The process of nanocrystal nucleation and growth was monitored using powder X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. Compared to existing solid-state routes for synthesizing colloidal Ge NCs, this approach requires fewer steps and is amenable ...


Group Iv Environmentally Benign, Inexpensive Semiconductor Nanomaterials For Solar Cells, Lisa Je Jun 2019

Group Iv Environmentally Benign, Inexpensive Semiconductor Nanomaterials For Solar Cells, Lisa Je

ENGS 86 Independent Projects (AB Students)

Modern solar cells are composed of silicon, cadmium tellurium, and copper indium gallium diselenide. While these materials are efficient, elements such as cadmium and indium are rare and expensive. To make this renewable energy source more inexpensive and sustainable, the Liu Optics lab is substituting expensive rare earth metals for more commonly found transition state metals. Work has been done to replace the solar cell layers composed of cadmium and gallium to replace them with glass, silicon, and/or thin films. Common metals such as germanium and tin are investigated and characterized to provide a platform for solar cell components.


Improving The Stability And Monodispersity Of Layered Cesium Lead Iodide Perovskite Thin Films By Tuning Crystallization Dynamics, Atefe Hadi, Bradley J. Ryan, Rainie D. Nelson, Kalyan Santra, Fang-Yi Lin, Eric W. Cochran, Matthew G. Panthani Jun 2019

Improving The Stability And Monodispersity Of Layered Cesium Lead Iodide Perovskite Thin Films By Tuning Crystallization Dynamics, Atefe Hadi, Bradley J. Ryan, Rainie D. Nelson, Kalyan Santra, Fang-Yi Lin, Eric W. Cochran, Matthew G. Panthani

Chemical and Biological Engineering Publications

Assembling halide perovskites into layered structures holds promise for addressing chemical and phase stability challenges; however, several other challenges need to be addressed to create efficient and stable halide perovskite devices. Layered halide perovskites (LHPs) suffer from broad distribution of layer thicknesses and bandgaps within thin films. Reducing polydispersity could substantially improve charge transport within LHP films and the performance of LHP-based solar cells. Herein, we focused on layering α-CsPbI3 ((C4H9NH3)2Csn-1PbnI3n+1) thin films. We found that (C4H9NH3)2Csn-1PbnI3n+1 with nominal layer thicknesses of n = 1, 2, 3, and 4 can be deposited at temperatures as low as ...


Nano-Enhanced Composite Membranes For Water Desalination, Benjamin Fredrik Victor Sundling Von Fürstenrecht Jun 2019

Nano-Enhanced Composite Membranes For Water Desalination, Benjamin Fredrik Victor Sundling Von Fürstenrecht

Materials Engineering

In theory single walled carbon nanotubes (SWCNT) will aid in ion rejection due hydrophobicity and smoothness of the SWCNT. An efficient means of water desalination utilizing SWCNT in a membrane seems plausible. A lyotropic liquid crystal (LLC) solution was made with a synthesized polymerizable surfactant methacryloxy ethyl hexadecyl dimethyl ammonium bromide (C16MA) to help with vertical alignment of SWCNT. Due to SWCNT lack of solubility and tendency to agglomerate in water, a dispersion performed using an inert surfactant centrimonium bromide (CTAB) to make sure that the SWCNT were homogeneously dispersed in the solution without altering the hexagonal packing factor of ...


Synthesis Of Germanium Nanocrystals From Solid-State Disproportionation Of A Chloride-Derived Germania Glass, Yujie Wang, Utkarsh Ramesh, Charles K. A. Nyamekye, Bradley J. Ryan, Rainie D. Nelson, Abdulla M. Alebri, Umar H. Hamdeh, Atefe Hadi, Emily A. Smith, Matthew G. Panthani Apr 2019

Synthesis Of Germanium Nanocrystals From Solid-State Disproportionation Of A Chloride-Derived Germania Glass, Yujie Wang, Utkarsh Ramesh, Charles K. A. Nyamekye, Bradley J. Ryan, Rainie D. Nelson, Abdulla M. Alebri, Umar H. Hamdeh, Atefe Hadi, Emily A. Smith, Matthew G. Panthani

Chemical and Biological Engineering Publications

Germanium nanocrystals (Ge NCs) have potential to be used in several optoelectronic applications such as photodetectors and light-emitting diodes. Here, we report a solid-state route to synthesizing Ge NCs through thermal disproportionation of a germania (GeOX) glass, which was synthesized by hydrolyzing a GeCl2·dioxane complex. The GeOX glass synthesized in this manner was found to have residual Cl content. The process of nanocrystal nucleation and growth was monitored using powder X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. Compared to existing solid-state routes for synthesizing colloidal Ge NCs, this approach requires fewer steps and is amenable ...


Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin Apr 2019

Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin

Nanoscience and Microsystems ETDs

Cystic fibrosis (CF) is the most common genetic disease resulting in the morbidity and mortality of Caucasian children and adults worldwide. Due to a genetic mutation resulting in malfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, CF patients produce highly viscous mucus in their respiratory tract. This leads to impairment of the mucociliary clearance of inhaled microbes. In addition to reduced microbial clearance, anoxic environmental conditions in the lungs promote biofilm-mode growth of the pathogenic bacterial species Pseudomonas aeruginosa. Chronic infections of P. aeruginosa begin in early childhood and typically persist until respiratory failure and death result. The ...


Microwave And Ultrasonic Assisted Synthesis Of Zeolites From Coal Fly Ash In Batch And Circulating Batch Operation, Tahani Hassn Aldahri Apr 2019

Microwave And Ultrasonic Assisted Synthesis Of Zeolites From Coal Fly Ash In Batch And Circulating Batch Operation, Tahani Hassn Aldahri

Electronic Thesis and Dissertation Repository

This research was focused on the production of zeolites from CFA throughutilizing ultrasound and microwave power. The initial conventional heating process of 6 h prior to microwave irradiation for samples with high solid-to-liquid (S/L) ratio (CFA mass/ NaOH solution volume) led to a higher yield of zeolite and decreased the synthesis time and consumption of energy,while keeping the high quality of the synthesized zeolite intact. The crystal growth of the nuclei generated over 6 h of conventional hydrothermal treatment was enhanced by the post-microwave heating. Ultrasound-assisted zeolitizationCFA was also applied in this research.

When ultrasound energy was applied ...


Progress Report I: Fabrication Of Nanopores In Silicon Nitride Membranes Using Self-Assembly Of Ps-B-Pmma, Unnati Joshi, Vishal Venkatesh, Hiromichi Yamamoto Mar 2019

Progress Report I: Fabrication Of Nanopores In Silicon Nitride Membranes Using Self-Assembly Of Ps-B-Pmma, Unnati Joshi, Vishal Venkatesh, Hiromichi Yamamoto

Protocols and Reports

This progress report describes fabrication of silicon nitride membranes from Si wafers using cleanroom techniques, and of nanopore preparation via a self-assembled PS-b-PMMA film. A 36.9 µm thick membrane is successfully prepared by KOH wet etching. The membrane is a layered structure of 36.8 µm thick Si and 116 nm thick silicon nitride. It is also exhibited that in the 47 nm thick PS-b-PMMA film, the nanopore structure is observed in the vicinity of a dust particle, but most of the area indicates lamellar domain structure. The thickness of PS-b-PMMA film will ...


Fabrication And Characterization Of Nanofiber Nylon-6-Mwcnt As An Electrochemical Sensor For Sodium Ions Concentration Detection In Sweat, Kelsey Mills Jan 2019

Fabrication And Characterization Of Nanofiber Nylon-6-Mwcnt As An Electrochemical Sensor For Sodium Ions Concentration Detection In Sweat, Kelsey Mills

Williams Honors College, Honors Research Projects

Fabrication and characterization nylon-6-MWCNT nanofiber as an electrochemical sensor to detect sodium ion concentrations specifically in sweat. Using contact angle to determine surface morphology and chronoamperometry testing to identify ideal sensor conditions, tests optimized parameters like weight percent of nylon or other polymers, carbon nanotube (CNT) isomer, and solution concentration to determine reproducibility of functional sensors. Utilizing the electric qualities of carbon nanotubes partnered with the sodium ion selectivity of calixarene treatment and polymers unique properties like flexibility and scalability create open an arena for optimizing sodium ion sensors for further development for functional prototypes. Morphology tests showed that the ...


Towards The Rational Design And Application Of Polymers For Gene Therapy: Internalization And Intracellular Fate, Landon Alexander Mott Jan 2019

Towards The Rational Design And Application Of Polymers For Gene Therapy: Internalization And Intracellular Fate, Landon Alexander Mott

Theses and Dissertations--Chemical and Materials Engineering

Gene therapy is an approach for the treatment of acquired cancers, infectious disease, degenerative disease, and inherited genetic indications. Developments in the fields of immunotherapies and CRISPR/Cas9 genome editing are revitalizing the efforts to move gene therapy to the forefront of modern medicine. However, slow progress and poor clinical outcomes have plagued the field due to regulatory and safety concerns associated with the flagship delivery vector, the recombinant virus. Immunogenicity and poor transduction in certain cell types severely limits the utility of viruses as a delivery agent of nucleic acids. As a result, significant efforts are being made to ...


A Data Analytics Approach For Rational Design Of Nanomedicines With Programmable Drug Release, Adam S. Mullis, Scott R. Broderick, Andrea M. Binnebose, Nathan Peroutka-Bigus, Bryan H. Bellaire, Krishna Rajan, Balaji Narasimhan Jan 2019

A Data Analytics Approach For Rational Design Of Nanomedicines With Programmable Drug Release, Adam S. Mullis, Scott R. Broderick, Andrea M. Binnebose, Nathan Peroutka-Bigus, Bryan H. Bellaire, Krishna Rajan, Balaji Narasimhan

Chemical and Biological Engineering Publications

Drug delivery vehicles can improve the functional efficacy of existing antimicrobial therapies by improving biodistribution and targeting. A critical property of such nanomedicine formulations is their ability to control the release kinetics of their payloads. The combination of (and interactions between) polymer, drug, and nanoparticle properties gives rise to nonlinear behavioral relationships and a large data space. These factors complicate both first-principles modeling and screening of nanomedicine formulations. Predictive analytics may offer a more efficient approach toward rational design of nanomedicines by identifying key descriptors and correlating them to nanoparticle release behavior. In this work, antibiotic release kinetics data were ...


Salt Mediated Self-Assembly Of Poly(Ethylene Glycol)-Functionalized Gold Nanorods, Hyeong Jin Kim, Wenjie Wang, Wei Bu, Md. Mir Hossen, Alejandra Londono-Calderon, Andrew C. Hillier, Tanya Prozorov, Surya Mallapragada, David Vaknin Jan 2019

Salt Mediated Self-Assembly Of Poly(Ethylene Glycol)-Functionalized Gold Nanorods, Hyeong Jin Kim, Wenjie Wang, Wei Bu, Md. Mir Hossen, Alejandra Londono-Calderon, Andrew C. Hillier, Tanya Prozorov, Surya Mallapragada, David Vaknin

Chemical and Biological Engineering Publications

Although challenging, assembling and orienting non-spherical nanomaterials into two- and three-dimensional (2D and 3D) ordered arrays can facilitate versatile collective properties by virtue of their shape-dependent properties that cannot be realized with their spherical counterparts. Here, we report on the self-assembly of gold nanorods (AuNRs) into 2D films at the vapor/liquid interface facilitated by grafting them with poly(ethylene glycol) (PEG). Using surface sensitive synchrotron grazing incidence small angle X-ray scattering (GISAXS) and specular X-ray reflectivity (XRR), we show that PEG-AuNRs in aqueous suspensions migrate to the vapor/liquid interface in the presence of salt, forming a uniform monolayer ...


Effect Of (Poly)Electrolytes On The Interfacial Assembly Of Peg Functionalized Gold Nanoparticles, Srikanth Nayak, Max Fieg, Wenjie Wang, Wei Bu, Surya Mallapragada, David Vaknin Jan 2019

Effect Of (Poly)Electrolytes On The Interfacial Assembly Of Peg Functionalized Gold Nanoparticles, Srikanth Nayak, Max Fieg, Wenjie Wang, Wei Bu, Surya Mallapragada, David Vaknin

Chemical and Biological Engineering Publications

We report on the effect of interpolymer complexes (IPCs) of poly(acrylic acid) (PAA) with poly(ethylene glycol) functionalized Au nanoparticles (PEG-AuNPs) as they assemble at the vapor-liquid interface, using surface sensitive synchrotron X-ray scattering techniques. Depending on the suspension pH, PAA functions both as a weak polyelectrolyte and a hydrogen bond donor, and these two roles affect the interfacial assembly of PEG-AuNPs differently. Above its isoelectric point, we find that PAA leads to the formation of a PEG-AuNPs monolayer at the interface with hexagonal structure. In the presence of high concentration of HCl (i.e., below the isoelectric point ...


Low Temperature Desiccants In Atmospheric Water Generation., Sunil Gupta Dec 2018

Low Temperature Desiccants In Atmospheric Water Generation., Sunil Gupta

Electronic Theses and Dissertations

Surging global water demand as well as changes to weather patterns and over exploitation of natural water sources, such as ground water, has made potable water a critical resource in many parts of the World already – one rapidly heading towards a crisis situation. Desalination has been adopted as a solution – this is however energy intensive and impractical for most of the developing countries - those most in need of water. A renewable source of energy is solar thermal and solar photovoltaic. A plentiful source of water is the humidity in the atmosphere. This research is to push the envelope in pairing ...


Determining The Degree Of [001] Preferred Growth Of Ni(Oh)2 Nanoplates, Taotao Li, Ning Dang, Wanggang Zhang, Wei Liang, Fuqian Yang Nov 2018

Determining The Degree Of [001] Preferred Growth Of Ni(Oh)2 Nanoplates, Taotao Li, Ning Dang, Wanggang Zhang, Wei Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results ...


Impact Of Substrate And Process On The Electrical Performance Of Screen-Printed Nickel Electrodes: Fundamental Mechanism Of Ink Film Roughness, Bilge N. Altay, Jerome Jourdan, Vikram S. Turkani, Hervé Dietsch, Dinesh Maddipatla, Alexandra Pekarovicova, Paul D. Fleming, Massood Atashbar Nov 2018

Impact Of Substrate And Process On The Electrical Performance Of Screen-Printed Nickel Electrodes: Fundamental Mechanism Of Ink Film Roughness, Bilge N. Altay, Jerome Jourdan, Vikram S. Turkani, Hervé Dietsch, Dinesh Maddipatla, Alexandra Pekarovicova, Paul D. Fleming, Massood Atashbar

Bilge Nazli Altay

In recent years, traditional printing methods have been integrated to print flexible electronic devices and circuits. Since process requirements for electronics diff er from those for graphic printing, the fundamentals require rediscovery mainly to optimize manufacturing techniques and to find cost reduction methods without compromising functional performance. In addition, alternative inks need to be formulated to increase the variety of functional inks and to pioneer new product developments. In this report, we investigate a thermoplastic-based nickel ink prototype to print electrodes using a screen-printing process. Process fundamentals are explored, and cost reduction methods are addressed by studying ...


Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden Nov 2018

Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden

Doctoral Dissertations

The U.S. produces 5559.6 million metric tons of carbon dioxide annually, of which 21% is produced by industrial processes. Steam reforming, an industrial process that accounts for 95% of all hydrogen production in industry, produces 134.5 million metric tons of carbon dioxide or around 11% of the total carbon dioxide produced by industry. This carbon dioxide is then either emitted or goes through a sequestration process that accounts for 75% of the plant's operational costs. An alternative reaction to steam reforming is dry reforming, which utilizes carbon dioxide rather than emitting it and can be used ...


Rate-Determining Step And Active Sites Probing For Platinum-Group-Metal Free Cathode Catalyst In Fuel Cell, Yechuan Chen Nov 2018

Rate-Determining Step And Active Sites Probing For Platinum-Group-Metal Free Cathode Catalyst In Fuel Cell, Yechuan Chen

Chemical and Biological Engineering ETDs

With the increasing demand on renewable energy, the fuel cell has attracted more and more interests because of its large power density and controllable size. However, the insufficiency of element abundance and unstable expensive price of conventional platinum-based electrocatalysts used in anode and cathode makes it essential to find their substitutes. As one of the most promising candidates to be used in cathode for oxygen reduction reaction (ORR), iron-nitrogen-carbon (Fe-N-C) catalysts have been widely investigated and get commercialized recently, but still lacks comprehensive understanding on the kinetic mechanism.

This dissertation has been divided into three parts with a discussion on ...


Electrocatalysts With High Activity And Stability For Polymer Electrolyte Membrane Fuel Cells, Zhongxin Song Sep 2018

Electrocatalysts With High Activity And Stability For Polymer Electrolyte Membrane Fuel Cells, Zhongxin Song

Electronic Thesis and Dissertation Repository

In addressing the activity and durability challenges facing electrocatalysts in polymer electrolyte membrane fuel cells (PEMFCs), atomic layer deposition (ALD) is emerging as a powerful technique for deposition of noble metals and transition metal oxides due to its exclusive advantages over other methods. The primary advantages of ALD are derived from the sequential, self-saturating, gas-surface reactions, and angstrom level control that take place during the deposition process. Therefore, ALD possesses the advantage in precisely control the particle size and uniform distribution on the substrate. By forming chemical bonds between the initial layer of ALD precursor and support atoms during the ...


Self-Cleaning Nanocomposite Membranes With Phosphorene-Based Pore Fillers For Water Treatment, Joyner Eke, Katherine Elder, Isabel Escobar Sep 2018

Self-Cleaning Nanocomposite Membranes With Phosphorene-Based Pore Fillers For Water Treatment, Joyner Eke, Katherine Elder, Isabel Escobar

Chemical and Materials Engineering Faculty Publications

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus and it possesses a band gap. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes that can self-clean. The goal of this study was to develop an innovative and robust membrane that is able to control and reverse fouling with minimal changes in membrane performance. To this end, for the first time, membranes have been embedded with phosphorene. Membrane modification was verified by the presence of phosphorus on membranes, along with changes in ...


Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang Aug 2018

Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang

Chemical and Biological Engineering Publications

Neurodegenerative diseases refer to disorders of the central nervous system (CNS) that are caused by neuronal degradations, dysfunctions, or death. Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease (APHD) are regarded as the three major neurodegenerative diseases. There is a vast body of literature on the causes and treatments of these neurodegenerative diseases. However, the main obstacle in developing an effective treatment strategy is the permeability of the treatment components to the blood-brain barrier (BBB). Several strategies have been developed to improve this obstruction. For example, nanomaterials facilitate drug delivery to the BBB due to their size. They ...


A Delayed Detached Eddy Simulation Model With Low Reynolds Number Correction For Transitional Swirling Flow In A Multi-Inlet Vortex Nanoprecipitation Reactor, Zhenping Liu, James C. Hill, Rodney O. Fox, Alberto Passalacqua, Michael G. Olsen Aug 2018

A Delayed Detached Eddy Simulation Model With Low Reynolds Number Correction For Transitional Swirling Flow In A Multi-Inlet Vortex Nanoprecipitation Reactor, Zhenping Liu, James C. Hill, Rodney O. Fox, Alberto Passalacqua, Michael G. Olsen

Chemical and Biological Engineering Publications

The objective of the presented work is to verify a delayed detached eddy simulation (DDES) model for simulating transitional swirling flow in a micro-scale multi-inlet vortex reactor (MIVR). The DDES model is a k-w based turbulence model with a low Reynolds number correction applied to the standard k-w model such that the Reynolds-averaged Navier-Stokes (RANS) component of the DDES model is able to account for low Reynolds number flow. By limiting the dissipation rate in the k-equation, the large-eddy simulation (LES) part of the DDES model behaves similarly to a one-equation sub-grid model. The turbulent Reynolds number is redefined to ...


Opto-Thermal Characterization Of Plasmon And Coupled Lattice Resonances In 2-D Metamaterial Arrays, Vinith Bejugam Aug 2018

Opto-Thermal Characterization Of Plasmon And Coupled Lattice Resonances In 2-D Metamaterial Arrays, Vinith Bejugam

Theses and Dissertations

Growing population and climate change inevitably requires longstanding dependency on sustainable sources of energy that are conducive to ecological balance, economies of scale and reduction of waste heat. Plasmonic-photonic systems are at the forefront of offering a promising path towards efficient light harvesting for enhanced optoelectronics, sensing, and chemical separations. Two-dimensional (2-D) metamaterial arrays of plasmonic nanoparticles arranged in polymer lattices developed herein support thermoplasmonic heating at off-resonances (near infrared, NIR) in addition to regular plasmonic resonances (visible), which extends their applicability compared to random dispersions. Especially, thermal responses of 2-D arrays at coupled lattice resonance (CLR) wavelengths were comparable ...


Creating Metamaterial Building Blocks With Directed Photochemical Metallization Of Silver Onto Dna Origami Templates, Md Mir Hossen, Lee Bendickson, Pierre Palo, Zhiqi Yao, Marit Nilsen-Hamilton, Andrew C. Hillier Jun 2018

Creating Metamaterial Building Blocks With Directed Photochemical Metallization Of Silver Onto Dna Origami Templates, Md Mir Hossen, Lee Bendickson, Pierre Palo, Zhiqi Yao, Marit Nilsen-Hamilton, Andrew C. Hillier

Ames Laboratory Accepted Manuscripts

DNA origami can be used to create a variety of complex and geometrically unique nanostructures that can be further modified to produce building blocks for applications such as in optical metamaterials. We describe a method for creating metal-coated nanostructures using DNA origami templates and a photochemical metallization technique. Triangular DNA origami forms were fabricated and coated with a thin metal layer by photochemical silver reduction while in solution or supported on a surface. The DNA origami template serves as a localized photosensitizer to facilitate reduction of silver ions directly from solution onto the DNA surface. The metallizing process is shown ...