Digital Commons Network^™

Functionalized Carbon Nanotubes In Hydrophobic Drug Delivery, Kun Chen

Dissertations

The direct incorporation of carboxylated carbon nanotubes (f-CNTs) into hydrophobic drug particles during their formation via anti-solvent precipitation is presented. The approach is tested using two drugs namely antifungal agent Griseofulvin (GF) and antibiotic Sulfamethoxazole (SMZ) that have very different aqueous solubility. It is observed that the f-CNTs dispersed in the water serve as nucleating sites for crystallization and are readily incorporated into the drug particles without altering crystal structure or other properties. The results show that the hydrophilic f-CNTs dramatically enhance dissolution rate for both drugs. The increased degree of functionalization leads to higher hydrophilicity and therefore faster dissolution …

Lightweight Thermal Management Material For Enhancement Of Through-Thickness Thermal Conductivity, Matthew Collins Weisenberger

Center for Applied Energy Research Faculty Patents

A flexible sheet of aligned carbon nanotubes includes an array of aligned nanotubes held in a polymer matrix material. The carbon nanotubes have an average length of between about 50 microns and about 500 microns. The polymer matrix has an average thickness of between about 10 microns and about 500 microns. The flexible sheet has a density of about 0.2 to about 1.0 glee and includes between about 98 to about 60 weight percent aligned carbon nanotubes and between about 2 and about 40 weight percent polymer. A tape of aligned carbon nanotubes, a method for producing a tape of …

Penetration Depth Variation In Atomic Layer Deposition On Multiwalled Carbon Nanotube Forests, David Alan Kane

Theses and Dissertations

Atomic Layer Deposition (ALD) of Al2O3 on tall multiwalled carbon nanotube forests shows concentration variation with the depth in the form of discrete steps. While ALD is capable of extremely conformal deposition in high aspect ratio structures, decreasing penetration depth has been observed over multiple thermal ALD cycles on 1.3 mm tall multiwalled carbon nanotube forests. SEM imaging with Energy Dispersive X-ray Spectroscopy elemental analysis shows steps of decreasing intensity corresponding to decreasing concentrations of Al2O3. A study of these steps suggests that they are produced by a combination of diffusion limited delivery of precursors with increasing precursor adsorption site …

The Use Of Nanosensors For Monitoring Civil Structures, Mousaied Farhoud

The Plymouth Student Scientist

Nano-sensors were tested to demonstrate whether nanotechnology could be obtained efficiently in the civil engineering field. The objective of the experiment was to reach a specific amount of resistance and electric conductivity produced by the sensors, which were later compared to other researches. The sensor was fabricated using carbon nanotubes (CNT) more specifically multi-walled carbon nanotubes (MWNT’s) as a conductive material and Polydimethylsiloxane (PDMS) as a polymer. Three samples were made with different CNT percentages. The material was then coated on a compact tension specimen and tested in tension. The results obtained were positive. The coating materials contained a good …

Water Processable N-Type Organic Semiconductor, Ruben S. Riquelme, Matthew Collins Weisenberger, Camila F. Gomez

Center for Applied Energy Research Faculty Patents

The present invention concerns a water-processable n-type semiconductor comprised of polyvinylpyrrolidone (PVP), carbon nanotubes (CNTs) and poly(ethyleneimine) (PEI). The semiconductors are prepared by providing PVP and CNTs in a hydrophilic slurry and dispersing therein small amounts of PEI.

Tunable Single-Walled Carbon Nanotube Fluorescence Emission Via Associated Dna Sequence, Jourdan T. Aromin, Bridget D. Dolash, Letha J. Sooter

Mountaineer Undergraduate Research Review

Single‑walled carbon nanotubes, or SWCNTs, are nanomaterials that possess unique characteristics, most importantly their differing structural arrangement in terms of chirality. Each single‑walled carbon nanotube exhibits a unique fluorescence spectra that is dependent upon its chirality. The association of single‑stranded DNA (ssDNA) with SWCNTs is monitored by near‑infrared fluorescence spectroscopy. The DNA:SWCNT hybrid exhibits fluorescence spectra dependence upon both the selected sequence and the selected chirality.

Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen R. Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen

Faculty Publications

Vertically aligned carbon nanotube array (VANTA) coatings have recently garnered much attention due in part to their unique material properties including light absorption, chemical inertness, and electrical conductivity. Herein we report the first use of VANTAs grown via chemical vapor deposition in a 2D interdigitated electrode (IDE) footprint with a high height-to-width aspect ratio (3:1 or 75:25 µm). The VANTA-IDE is functionalized with an antibody (Ab) specific to the human cancerous inhibitor PP2A (CIP2A)—a alivary oncoprotein that is associated with a variety of malignancies such as oral, breast, and multiple myeloma cancers. The resultant immunosensor is capable of detecting CIP2A …

Functional Optimization Of Carbon Nanotubes, Taylor Davis, Sr. Brian Iverson

Journal of Undergraduate Research

The objective of this project was to create, characterize, and optimize carbon nanotube (CNT) films as a surface functionalization strategy through modifying the growth, infiltration, and patterning during fabrication.

Carbon nanotubes have drawn attention in various disciplines in the scientific community because of their incredible strength, hardness, wettability (hydrophobicity), as well as their kinetic and electrical properties. At BYU specifically, they are being used in diverse applications including fabrication of superhydrophobic surfaces and interdigitated electrode biosensors.

Carbon nanotubes can be delicate with a diameter of only a few nanometers when grown. However, the process of carbon infiltration can be used …

Combined Effect Of Oxidative Treatment And Residual Alcohol On The Mechanics Of A Multiwalled Carbon Nanotube Laden Interface, William Ivancic, Christopher L. Wirth

Chemical & Biomedical Engineering Faculty Publications

Single and multiwalled carbon nanotubes (SWCNT & MWCNT) have been investigated over the past three decades because of their excellent properties, including their mechanical strength and large electrical and thermal conductivities. Incorporating CNTs into consumer and industrial products is challenging because of strong attractive interactions, heterogeneity, and lack of separation techniques for these nanomaterials. Further challenges include those associated with CNT interaction and adsorption to interfaces. In the present work, the properties of an air/water interface laden with industrial grade MWCNTs with systematically varied oxidative treatment in nitric acid were measured. The duration of treatment was varied and the surface …

Implemenatation Of Additive Print Manufacturing Processes For The Development Of Flexible Thermal Sensors, Vikram Shreeshail Turkani

Masters Theses

This work focuses on the design, fabrication and characterization of novel flexible thermal sensors using additive print manufacturing processes. Initially, a carbon nanotube (CNT) based negative temperature coefficient (NTC) thermistor was fabricated on a flexible polyethylene terephthalate (PET) substrate using screen and gravure printing processes. The thermistor consists of two silver (Ag) electrodes deposited using screen printing process. A CNT based sensing layer was deposited using gravure printing process on the Ag electrodes. Finally, a primary polymer and a secondary Ag encapsulation layer were deposited using screen printing process. The capability of the fabricated thermistor was investigated by measuring its …

An Introductory Study Of Solid Materials For Capture And Catalysis Of Waste Stream Chemicals, Steven Kyle Butler

Theses and Dissertations

Heterogeneous catalysts are key materials in research and industry. Herein we study two materials in different stages of development toward being applied as heterogeneous catalysts. First, MoO3SnO2 was synthesized and studied as a catalytic system similar to Sn-beta zeolites. While the Mo-based catalyst did not show similar activity to Sn-beta, it did show interesting reactivity in activating carbonyls and oxidizing organic substrates. Second, a method was developed for grafting amines onto carboxylic acid functionalized carbon nanotubes for CO2 capture. The method was successful for grafting monomer ethylamine groups onto CNT and can be further developed to allow for polymeric amine …

Graphene Foam And Helically Coiled Carbon Nanotubes As Electrodes In Energy Storage Devices, Anthony Childress

All Dissertations

Since their inception, carbon nanomaterials have been exploited for use in energy storage. The discovery of carbon nanotubes and the later isolation of graphene opened new avenues in electrode research for batteries and electric double layer capacitors (EDLCs). Their combination of flexibility, mechanical robustness, and electronic conductivity make them ideal for use as active materials and additives. My research has focused on the synthesis and implementation of helical carbon nanotubes (HCNTs) for supercapacitors and few-layer graphene in the form of graphene foam (GF) for aluminum-ion batteries. The presence of defects and dopants was controlled in each system to determine how …

Carbon Nanotube Yarn Based Dye Sensitized Solar Cells With Enhanced Electron/Hole Pair Recombination Prevention Characteristics, Glenn E. Grissom

Theses and Dissertations

Carbon nanotube yarn based solar cells (CNTYSCs) show promise in a variety of applications such as military and smart fabrics. We use a highly aligned and interwoven Carbon nanotube yarn (CNTY) for the working electrode (WE) and counter electrode (CE), to create a flexible super strong, conductive, and photo active surface for the support of a calcined TiO2 nano-solution and macro-solution deposition as a base for added functionalizations of a dye-sensitized solar cell (DSSC) that is able to maintain its flexibility and integrity. The CNT fiber based solar cells have power conversion ability that is independent of the direction of …

Method For Production Of Germanium Nanowires Encapsulated Within Multi-Walled Carbon Nanotubes, Mark Crocker, Rodney Andrews, Arumugam Pandurangan, Dali Qian

Center for Applied Energy Research Faculty Patents

A method is provided for producing germanium nanowires encapsulated within multi-walled carbon nanotubes. The method includes the steps of performing chemical vapor deposition using a combined germanium and carbon source having a general formula of GeR_(4-x)L_x, where x=0, 1, 2, or 3; R is selected from a group consisting of alkyl, cycloalkyl or aryl and L=hydrogen, halide or alkoxide and growing germanium nanowires encapsulated within multi-walled carbon nanotubes on a substrate. A reaction product of that method or process is also provided.

An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Faculty Publications

The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the …

Fabrication And Analysis Of Multifunctional Carbon Nanotube Electrical Conductors, Andrew Robert Bucossi

Theses

Carbon nanotube (CNT) bulk conductors have been proposed as an alternative material to metals for power and data transmission applications due to their light weight, flexure tolerance, and chemical stability. However, current fabrication technologies prevent bulk CNT wires from matching the electrical properties of individual CNTs, providing opportunity for researchers to improve CNT wire fabrication.

In this work, CNT conductors have been advanced using high-purity laser-vaporized single wall carbon nanotubes (SWCNTs). Acid dispersion and extrusion of SWCNTs into a coagulant bath was used to fabricate wires and systematic modification of the process has determined that coagulation dynamics govern the resulting …

Engineering Hyaluronic Acid Carbon Nanotube Nanofibers: A Peripheral Nerve Interface To Electrically Stimulate Regeneration, Elisabeth M. Steel

Wayne State University Dissertations

Peripheral nerve injuries annually affect hundreds of thousands of people globally. Current treatments like the gold standard autograft and commercially available nerve guide conduits (NGC) are insufficient to repair long gap peripheral nerve injuries. NGCs can aid recovery but lack key microenvironment cues that promote nerve regeneration. We hypothesized that providing topographical, mechanical, and electrical guidance cues through a nanofibrous composite biopolymer would result in improved neuron growth metrics using an in vitro model. We embedded hydrophilic carbon nanotubes (CNT) within hyaluronic acid (HA) nanofibers by electrospinning. The aims of this study were (1) to define the topographical, nanomechanical, and …

Polypyrrole (Ppy) Coated Patterned Vertical Carbon Nanotube (Pvcnt) Dry Ecg Electrode Integrated With A Novel Wireless Resistive Analog Passive (Wrap) Ecg Sensor, Mohammad Jomah I. Abu Saude

Electronic Theses and Dissertations

Biopotential signals such as electroencephalography (EEG), electrocardiography (ECG or EKG), electrooculogram (EOG), and electromyography (EMG) play vital roles in health and clinical diagnoses, monitoring, and therapy. In addition, these signals are required for many nonclinical applications such as Neurofeedback and Brain-Computer Interface (BCI). The quality of the measurement relies on the electrical and mechanical properties of the electrode. Conventional wet or gel impedimetric electrodes provide an excellent signal due to the conductive fluids or gel, which reduces the skin-contact impedance and maintains contact during movement. However, they operate for a short duration; the quality of the signal degrades due to …

Fabrication Of Mnox/Mwcnts-Gc Nanocatalyst For Oxygen Evolution Reaction, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Amr M. Arafa Eng.

Chemical Engineering

Manganese oxide (MnOx) and multiwalled carbon nanotubes (MWCNTs) are intended to modify the GC electrode for oxygen evolution reaction (OER). Optimization of MnOx loading is carried out and the deposition of 55 cycles was sufficient to obtain the highest activity toward OER. The stability of the catalyst is enhanced by the addition of MWCNTs. As a result, an amount of 22 kWh/Kg of O2 of energy is saved. Several techniques including cyclic voltammetry, linear sweep voltammetry, chronoamperometry, chronopotentiometry, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy will be combined to track the catalyst activity and to determine its morphology …

Metal Nanoparticles/Carbon Nanotube Modified Electrodes For Voltammetric Determination Of Boron, Lokman Li̇v, Zekerya Dursun, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This study describes a sensitive and accurate voltammetric method for determination of boron using metal nanoparticles/carbon nanotube modified electrodes. The oxidation peak of Alizarin Red S (ARS) at -0.59 V in the boron-ARS complex formed in ammonium/ammonia buffer solution (pH 8.5) was evaluated as a response. The electrode modification conditions and experimental parameters affecting the peak height were optimized. The characteristics of modified electrodes were investigated using cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscope, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The limits of detection (3s$_{y/x})$ and the analytical ranges for gold nanoparticles/carbon …

Heat, Charge And Spin Transport Of Thin Film Nanostructures, Devin John Wesenberg

Electronic Theses and Dissertations

Understanding of fundamental physics of transport properties in thin film nanostructures is crucial for application in spintronic, spin caloritronics and thermoelectric applications. Much of the difficulty in the understanding stems from the measurement itself. In this dissertation I present our thermal isolation platform that is primarily used for detection of thermally induced effects in a wide variety of materials. We can accurately and precisely produce in-plane thermal gradients in these membranes, allowing for thin film measurements on 2-D structures. First, we look at thermoelectric enhancements of doped semiconducting single-walled carbon nanotube thin films. We use the Wiedemann-Franz law to calculate …

Mixed Matrix Flat Sheet And Hollow Fiber Membranes For Gas Separation Applications, Nicholas W. Linck

Theses and Dissertations--Chemical and Materials Engineering

Mixed matrix membranes (MMM) offer one potential path toward exceeding the Robeson upper bound of selectivity versus permeability for gas separation performance while maintaining the benefits of solution processing. Many inorganic materials, such as zeolites, metal-organic frameworks, or carbon nanotubes, can function as molecular sieves, but as stand-alone membranes are brittle and difficult to manufacture. Incorporating them into a more robust polymeric membrane matrix has the potential to mitigate this issue.

In this work, phase inversion polymer solution processing for the fabrication and testing of asymmetric flat sheet mixed matrix membranes was employed with CVD-derived multiwall carbon nanotubes (MWCNTs) dispersed …