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Electronic Communication Between Co And Ru Sites Decorated On Nitrogen-Doped Carbon Nanotubes Boost The Alkaline Hydrogen Evolution Reaction, Mengting Gao #, Ying Wei #, Xuemeng Huo, Wenjie Zhu, Qingqing Liu, Jinyuan Qiang, Wanwan Liu, Ying Wang, Xu Li, Jianfeng Huang, Yongqiang Feng

Online First

Designing highly efficient Pt-free electrocatalysts with low overpotential for the alkaline hydrogen evolution reaction (HER) remains a significant challenge. Here, a novel and efficient Co, Ru bimetallic electrocatalyst composed by CoRu nanoalloy decorated on the N-doped carbon nanotubes (N-CNTs), deriving from the fullerenol and melamine via hydrothermal treatment followed by pyrolysis. Benefiting from the electronic communication between Co and Ru sites, the as-obtained CoRu@N-CNTs exhibited superior electrocatalytic HER activity. To deliver a current density of 10 mA cm^-2, it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV dec^-1 in 1 …

Characterization Of Carbon Nanotube/Polystyrene Composites Prepared Via Microwave-Induced Polymerization, Hubert Agamasu

Electronic Theses and Dissertations

Carbon nanotubes (CNTs), with their excellent mechanical properties, are well suited to the production of composites with good strength-to-weight ratio. However, the use of nanotubes as reinforcement is hampered by the lack of interaction between their inert surfaces and matrices. This, coupled with the van der Waal’s interactions between individual nanotubes, leads to agglomeration of CNTs in media. Functionalization is an efficient means to disperse nanotubes as well as increase their reactivity. The irradiation of CNTs with microwaves generates instantaneous, localized heating, being used in this work to trigger the rapid, thermal, free radical polymerization of styrene. Under microwaves, olefin-functionalized …

Application Of Icp Rie Techniques To Produce Cnt Arrays, Mujtaba Yar Khan Siddiqui

Theses

Introducing biomolecules into cells is an important process in the field of gene therapy and in developing cures for debilitating illnesses such as HIV and cancer. However, the currently used methods for cellular transfection are slow, inefficient and expensive, causing them to be restrictive. A solution to this problem would be the carbon nanotube (CNT) array devices developed by our research group, which have been shown to be highly efficient at transporting biomolecules into cells. In the current manufacturing process, a sacrificial template with vertically aligned nanopores is used to deposit carbon in, the template then is etched away to …

Electronic Structures And Dielectric Function Of (5, 5) Cnt-C2h4o System: A First-Principles Study On The Detection Capability Of Cnt For Gas Sensing Applications, Alvanh Alem Pido, Art Anthony Munio

Turkish Journal of Chemistry

Carbon nanotubes (CNTs) are known to have a wide range of applications in various fields of discipline. In this research, the ability of metallic armchair (5, 5) CNT to detect acetaldehyde (C2 H4 O) was investigated using first-principles density functional theory (DFT) as implemented in Quantum ESPRESSO with the Generalized Gradient Approximation (GGA). Accordingly, it was found that C2 H4 O preserved the metallic behavior of the CNT. However, some bands are found to have overlapped in both the valence and conduction regions of the electronic structures of the resulting system that are mainly caused by the p orbitals of …

Measuring Diffusion Through Carbon Nanotube Arrays With Fluorescent Spectroscopy, Michael Machold

Theses

Carbon nanotube (CNT) arrays are emerging as versatile nanostructures that can be used in many applications including gene transfection technology. To understand the transport of molecules through an array of CNTs, diffusion of molecules was studied experimentally and analytically. A procedure using fluorescent spectroscopy was developed to measure the concentration change of fluorescein salt in a two-reservoir system separated by a CNT array. Experiments were conducted to measure how changing the initial concentration gradient and reservoir volume size impacted the diffusivity of the system. For 2 mL reservoirs, diffusivities were measured between 2.56*10^(-11) m^2/s and 3.51*10^(-11) m^2/s. Diffusivities were measured …

Experimental And Computational Fluid Dynamics Investigation Of Mechanisms Of Enhanced Oil Recovery Via Nanoparticle-Surfactant Solutions, Nurudeen Yekeen, Ali Masoud Ali Elakkari, Javed Akbar Khan, Muhammad Ali, Ahmed Al-Yaseri, Hussein Hoteit

Research outputs 2022 to 2026

The enhancement in surfactant performance at downhole conditions in the presence of nanomaterials has fascinated researchers’ interest regarding the applications of nanoparticle-surfactant (NPS) fluids as novel enhanced oil recovery (EOR) techniques. However, the governing EOR mechanisms of hydrocarbon recovery using NPS solutions are not yet explicit. Pore-scale visualization experiments clarify the dominant EOR mechanisms of fluid displacement and trapped/residual oil mobilization using NPS solutions. In this study, the influence of multiwalled carbon nanotubes (MWCNTs), silicon dioxide (SiO₂), and aluminum oxide (Al₂O₃) nanoparticles on the EOR properties of a conventional surfactant (sodium dodecyl benzene sulfonate, …

Mechanical Properties And Performance Of A Novel Nano-Engineered Unitized Composite With Quasi-Isotropic Layup, Brian Matthew Pudlo

Theses and Dissertations

Carbon nanotubes (CNTs) exhibit outstanding mechanical, electrical, and thermal properties, but are a challenge to effectively implement into macroscopic composites for aerospace applications. This research investigates the mechanical properties and performance of a newly developed hybrid NanoStitch composite, alongside a control polymer matrix composite, at room temperature. Both composite material systems investigated in this work have quasi-isotropic layup. Monotonic tension-tofailure, tension-tension fatigue, and creep tests were performed to characterize the performance of the composites under cyclic and sustained loading. Experimental results obtained for the quasi-isotropic NanoStitch composite were compared to those obtained for the quasi-isotropic control composite. The properties and …

Using Nanomaterials As Excellent Immobilisation Layer For Biosensor Design, Azeez Olayiwola Idris, Seyi Philemon Akanji, Benjamin O. Orimolade, Foluke Omobola Grace Olorundare, Shohreh Azizi, Bhekie Mamba, Malik Maaza

Research outputs 2022 to 2026

The endless development in nanotechnology has introduced new vitality in device fabrication including biosensor design for biomedical applications. With outstanding features like suitable biocompatibility, good electrical and thermal conductivity, wide surface area and catalytic activity, nanomaterials have been considered excellent and promising immobilisation candidates for the development of high-impact biosensors after they emerged. Owing to these reasons, the present review deals with the efficient use of nanomaterials as immobilisation candidates for biosensor fabrication. These include the implementation of carbon nanomaterials—graphene and its derivatives, carbon nanotubes, carbon nanoparticles, carbon nanodots—and MXenes, likewise their synergistic impact when merged with metal oxide nanomaterials. …

Highly Stretchable And Sensitive Sbs/Gr/Cnts Fibers With Hierarchical Structure For Strain Sensors, Mengsui Liu, Yaping Sheng, Chenggang Huang, Chenggang Huang, Yanfen Zhou, Liang Jiang, Mingwei Tian, Shaojuan Chen, Stephen Jerrams, Fenglei Zhou, Jianyong Yu

Articles

Most of the reported flexible strain sensors can only normally sense external stretch in a quite narrow working range and with low sensitivity. In order to overcome these drawbacks, elastomeric fiber based strain sensors incorporating graphene (Gr) and carbon nanotubes (CNTs) were initially fabricated via coaxial wet spinning. The solution etching method was employed for forming a 1D@2D@1D hierarchical structure, with pores and microcracks on fibers, to reconstruct their conductive networks. The solution etched fiber based strain sensors achieved a significant improvement in obtaining a high maximum gauge factor of 1667 and capability of working over a wide strain range …

Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad

Dissertations, Master's Theses and Master's Reports

There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …

Characterization Of 1d And 2d Materials With Tip-Enhanced Raman Spectroscopy, María Olivia Avilés

Electronic Thesis and Dissertation Repository

Carbon-based materials, such as 1D single-walled carbon nanotubes (SWCNT) or 2D graphene, are promising materials for a variety of applications in energy storage, biosensors, and medical imaging applications. Similarly, beyond graphene, 2D transition metal dichalcogenides (TDM) that can have either a metallic or semiconducting character have gained interest for potential applications in electronics and photonics. Specifically, metallic TMDs such as vanadium disulfide (VS₂) show potential applications in optoelectronics and lithium-ion batteries. On the other hand, semiconducting TDMs like tungsten disulfide (WS₂) show a direct band gap, making them interesting for photovoltaic applications, transistors, or photodetectors. The …

Design And Characterization Of A Miniaturized Spectrometer For Wearable Applications, Tyler Richard Westover

Theses and Dissertations

As individual health monitors continue to become more widely adopted in helping individuals make informed decisions, new technologies need to be developed to obtain more biometric data. Spectroscopy is a well-known tool to gain biological information. Traditionally spectrometers are large and expensive making personal or wearable health monitors difficult. Here we present the development and characterization of a miniaturized short wavelength infrared spectrometer for wearable applications. We present a carbon nanotube parallel hole collimator can effectively select a narrow set of allowed angles of light to be separated by a linear variable filter and detected at a photodiode array making …

Fabrication And Characterization Of Carbon Nanotube Metal Matrix Composites For Use In Photovoltaic Gridline Applications, Cayla M. Nelson

Nanoscience and Microsystems ETDs

Performance reliability is crucial for photovoltaic (PV) cells in both terrestrial and space-based applications. Electrical efficiency losses over time are heavily impacted by electrical losses due to microcracks within the cell structure and metallization failure. Mechanical stresses and thermal cycling of the device can lead to fracture of the current-carrying metal (Ag) lines on the surface of the device, significantly reducing output power. Incorporating carbon nanotubes (CNTs) into PV metal lines as a reinforcement, forming a CNT/Ag metal matrix composite (MMC), enhances the electrical and mechanical performance of the device. In this work the influence of CNT/Ag MMCs were explored …

Patterned And Infiltrated Vertically Aligned Carbon Nanotube Ultra-Black Materials, Kevin Laughlin

Theses and Dissertations

Ultra-black materials reflect less than 1% of incident light, and are used in a wide variety of applications from low signal detector systems, to jewelry. The darkest ultra-black materials are made with vertically aligned carbon nanotubes (VACNTs). One downside to these VACNT based ultra-black material, is they are extremely fragile, and the types of surfaces they can be grown on is limited. Here I created a strengthened ultra-black material that can withstand light handling and drying from water exposure, and can be transferred to other substrates while remaining ultra-black. I also present theoretical models with supporting data on how to …

Electrical And Mechanical Properties Of Polymer Nanocomposites, Nuwansiri N.K. Getangama

Electronic Thesis and Dissertation Repository

This thesis consists of three projects concerning the electrical and mechanical properties of polymer nanocomposites. We study the effect of nanoscale filler particles on the polymer dynamics at different length and time scales. In the first study, poly(ethylene oxide) (PEO)-multiwalled carbon nanotubes (MWCNT) nanocomposites with a MWCNT concentration ranging from 0 to 5 wt\% were prepared by both melt-mixing and twin-screw extrusion. Their electrical properties were studied over a wide range of frequency and temperature using a dielectric spectrometer. A percolation transition is observed at which the electrical conductivity of the nanocomposites increases by several orders of magnitude. The percolation …

Robust Design Methodologies Under Performance Variations For More Than Moore Technologies: Cnfets & 3dics, Satya Keerthi Vendra

Dissertations and Theses

Various emerging technologies have shown great potential of supplementing silicon transistors as Moore's law slows down. One such disruptive technology, Carbon Nanotube Field Effect Transistors (CNFET), among others, promises increased speed and integration with reduced power consumption. However, due to a limited controllability over the Carbon Nano-tube(CNT) growth process, CNFETs show large variations in their performance and behavior. It is therefore difficult to predict and model their behavior while design suggestions are also challenging. CNT variations are important for a realistic delay modelling. Due to the presence of CNT-specific variations, conventional CMOS evaluation techniques cannot be used for CNFETs.

This …

A Core–Shell Au@Tio2 And Multi-Walled Carbon Nanotube-Based Sensor For The Electroanalytical Determination Of H2o2 In Human Blood Serum And Saliva, Ayman Ali Saeed, Mohammed Nooredeen Abbas, Waheed Fathi El-Hawary, Yousry Moustafa Issa, Baljit Singh

Articles

A hydrogen peroxide (H2O2) sensor was developed based on core–shell gold@ titanium dioxide nanoparticles and multi-walled carbon nanotubes modified glassy carbon electrode (Au@TiO2/MWCNTs/GCE). Core–shell Au@TiO2 material was prepared and characterized using a scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX), transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD) and Zeta-potential analyzer. The proposed sensor (Au@TiO2/MWCNTs/GCE) was investigated electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The analytical performance of the sensor was evaluated towards H2O2 using differential pulse voltammetry (DPV). The proposed sensor exhibited excellent stability and sensitivity with a linear concentration …

A Highly Conductive, Flexible, And 3d-Printable Carbon Nanotube-Elastomer Ink For Additive Bio-Manufacturing, Andy Shar, Phillip Glass, Daeha Joung Ph.D.

Undergraduate Research Posters

The synthesis of a highly conductive, flexible, 3D-printable, and biocompatible ink has been of great interest in the field of bio-based additive manufacturing. Various applications include ultra-sensitive, microscale tactile sensors, patient-customizable scaffolds for cardiac and nerve tissue regeneration, and flexible electrocardiogram (ECG) electrodes. Here, a novel elastomeric carbon nanocomposite is presented consisting of amino-functionalized carbon nanotubes (CNT-NH₂) homogenously dispersed in a one-part room-temperature vulcanizing (RTV) silicone matrix. The use of acetone as a swelling solvent aids in electrical percolation through the elastomer matrix. CNT-NH₂ ratios can be tuned to fit various needs; higher tensile strength is favored …

Molecular Modeling Of High-Performance Thermoset Polymer Matrix Composites For Aerospace Applications, Prathamesh P. Deshpande

Dissertations, Master's Theses and Master's Reports

The global efforts from major space agencies to transport humans to Mars will require a novel lightweight and ultra-high strength material for the spacecraft structure. Three decades of research with the carbon nanotubes (CNTs) have proved that the material can be an ideal candidate for the composite reinforcement if certain shortcomings are overcome. Also, the rapid development of the polymer resin industry has introduced a wide range of high-performance resins that show high compatibility with the graphitic surface of the CNTs. This research explores the computational design of these materials and evaluates their efficacy as the next generation of aerospace …

Moisture Dependence Of Electrical Resistivity In Under-Percolated Cement-Based Composites With Multi-Walled Carbon Nanotubes, Geuntae Hong, Seongcheol Choi, Doo-Yeol Yoo, Taekgeun Oh, Yooseob Song, Jung Heum Yeon

Civil Engineering Faculty Publications and Presentations

Cement-based piezoresistive composites have attracted significant attention as smart construction materials for embedding self-sensing capability in concrete infrastructure. Although a number of studies have been conducted using multi-walled carbon nanotubes (MWCNTs) as a functional filler for self-sensing cement-based composites, studies addressing the influence of the internal moisture state on the electrical properties are relatively scant. In this study, we aim to experimentally investigate the effect of internal moisture state on the electrical resistivity of cement-based composites containing MWCNTs as an electrically conductive medium to raise a need for calibration of self-sensing data considering the internal moisture state. To this end, …

Titanium Interconnection In Metallized Carbon Nanotube Conductors, Dylan J. Mcintyre

Theses

Metallized carbon nanotube (CNT) networks aim to achieve conductivities competitive with bulk metals, while retaining the favorable temperature coefficient of resistance (TCR) for CNT materials. Cu is the predominant metal for high conductivity applications due to cost and availability. However, microscopy shows that Cu poorly wets a CNT surface and requires an adhesion metal for an improved physical and electrical interface. The present dissertation utilizes thermal evaporation as a direct method to evaluate 2-D coatings of Ti as an interfacial metal for bulk Cu-CNT hybrids. Specifically, a 10 nm Ti layer maintained a continuous and uniform coating after annealing to …

Manipulation Of Carbon Nanotube Growth Direction Utilizing Magnetic Fields, Rees D. Folaron

Theses

Carbon nanotubes are, as the name implies, nano-scale cylindrical structures consisting of monolayer carbon atoms arranged in a hexagonal lattice rolled into tubes. The resulting tubes can either be multi-walled or single walled and have a plethora of handy properties that make them functional in a wide range of applications. Carbon nanotubes, or CNTs, are known to be ultra-high strength, low weight, material that possess highly conductive electrical and thermal properties. These attributes make CNTs well suited for virtually any application requiring high strength, durability, electrical conductivity, thermal conductivity, and lightweight. As such, carbon nanotubes are being applied to a …

Preparation Of Co1-XS-Mns@Cnts/Cnfs For Electrocatalytic Oxygen Reduction Reaction, Fang-Yan Liu, Qian Zhang, Yue-Kun Li, Feng Huang, Meng-Ye Wang

Journal of Electrochemistry

As an important cathode reaction in fuel cells and metal-air batteries, oxygen reduction reaction (ORR) is a complex reaction of slow kinetics, which severely limits performances of fuel cells and metal-air batteries. Therefore, it is of key importance to find an efficient and stable electrocatalyst to promote ORR. Carbon-based materials, which possess high conductivity, good stability and large specific surface area, are usually used in electrocatalytic ORR. However, pure carbon-based materials exhibit low efficiency. Coupling carbon-based materials with manganese (Mn) and cobalt (Co) transition metals containing 3d orbitals is an effective way to improve electrocatalytic performance. Herein, carbon nanofibers containing …

Controlled Reduction Of Graphene Oxide And Graphene Oxide-Carbon Nanotube Hybrids And Their Applications, Samar Azizighannad

Dissertations

Graphene and graphene derivatives are widely used in diverse research and industrial applications. Graphene production on a large scale is carried out by exfoliating graphite oxide and producing graphene oxide (GO), which comprises of graphene sheets with different oxygen-containing functional groups such as hydroxyl, carboxyl, and carbonyl. GO is reduced to reduced graphene oxide (rGO), which has properties that are closer to graphene. Properties of GO and rGO depend upon the oxygen content, and the effect of reducing oxygen content on the aqueous behavior of rGOs is not well understood.

In an effort to understand how properties of rGO change …

Removal Of Hexavalent Chromium By Encapsulated Chitosan-Modified Magnetic Carbon Nanotubes: Fixed-Bed Column Study And Modelling, Mian Muhammad-Ahson Aslam, Walter Den, Hsion-Wen Kuo

Water Resources Science and Technology Faculty Publications

A new type of composite adsorbent, encapsulated chitosan-modified magnetic carbon nanotubes (CS/MWCNTs/Fe) beads were used to remove hexavalent chromium (Cr(VI)) from aqueous solutions in a fixed-bed column. Among the various combination of operating parameters, we obtain a maximum volume of treated effluent (210 mL) under the following conditions: flow rate, 1 mL min⁻¹; bed height, 8 cm; feed Cr(VI) concentration, 30 mg L⁻¹; and solution pH, 4.0 ± 0.2. The corresponding adsorption capacity was 1.54 mg g^-1 and the overall Cr(VI) removal efficiency was 54 %. In characterizing the dynamics of the adsorption process and …

A Preliminary Study On The Chiral Vector Approach In Determining The Optimum Structure Of Carbon Nanotubes And Its Correlation To The Chemical Potential Energy Using Avogadro, James Harris R. Bajande, Bren Daniel J. Ebriega, Justin Randolph N. Labios, Mike Lester D. Uy

DLSU Senior High School Research Congress

In this study, the following quantitative properties of carbon nanotubes were explored: the chiral vectors, which are numbers that describe the carbon nanotubes’ structure, and properties such as chemical potential energy. The objective of this study is to simulate various carbon nanotube structures with chiral vectors that range from (0-3) and find a relation between these chiral vectors and the chemical potential energy. Using the software Avogadro, 12 carbon nanotubes with different chiral vectors (n, m) were simulated. These carbon nanotubes were of different lengths to keep the number of atoms in the molecules as close to 100 as possible. …

Encapsulated Chitosan-Modified Magnetic Carbon Nanotubes For Aqueous-Phase Crvi Uptake, Mian Muhammad-Ahson Aslam, Walter Den, Hsion-Wen Kuo

Water Resources Science and Technology Faculty Publications

This work demonstrates the performance of a composite adsorbent encapsulated with chitosan (CS) and maghemite-doped multiwall carbon nanotubes (MWCNTs). Hexavalent chromium (Cr^VI) was used as the representative hazardous heavy metal to characterize the adsorption behavior of the composite beads. The chromium speciation chemistry combined with the chitosan surface chemistry rendered pH at 4 to be the optimized condition in which the uptake of Cr^VI was quantitatively most effective. The Langmuir isotherm with a maximum adsorption capacity of 119 mg g⁻¹ at 298 K was observed. The Cr^VI adsorption studies using partial compositions of the beads …

Mechanical Properties And Performance Of A Novel Nano-Engineered Unitized Composite For Aerospace Systems, Benjamin C. Lam

Theses and Dissertations

Carbon nanotubes (CNTs) exhibit outstanding mechanical properties, such as exceptionally high tensile stiffness and strength, combined with excellent electrical and thermal characteristics. This research investigates the mechanical properties and performance of a newly developed hybrid nano-engineered composite. The carbon fiber/polymer matrix composite incorporates a forest of vertically aligned CNTs, called NanoStitch, between the prepreg plies. Basic tensile properties of both material systems were investigated for both on-axis [0/90] and off-axis [±45] fiber orientations at room temperature. Tension-tension fatigue tests were performed with a frequency of 1.0 Hz and a ratio of minimum stress to maximum stress of R= 0.05. Fatigue …

Transcriptome Profile Alterations With Carbon Nanotubes, Quantum Dots, And Silver Nanoparticles: A Review, Cullen Horstmann, Victoria Davenport, Min Zhang, Alyse Peters, Kyoungtae H. Kim

College of Natural and Applied Sciences

Next-generation sequencing (NGS) technology has revolutionized sequence-based research. In recent years, high-throughput sequencing has become the method of choice in studying the toxicity of chemical agents through observing and measuring changes in transcript levels. Engineered nanomaterial (ENM)-toxicity has become a major field of research and has adopted microarray and newer RNA-Seq methods. Recently, nanotechnology has become a promising tool in the diagnosis and treatment of several diseases in humans. However, due to their high stability, they are likely capable of remaining in the body and environment for long periods of time. Their mechanisms of toxicity and long-lasting effects on our …

An Improvement Of Current Driving And Electrical Conductivity Properties Incovetics, Mesut Atasoyu, Emi̇n Argun Oral, Mehmet Ertuğrul

Turkish Journal of Physics

Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 $10^{7}$ $A /m^{2}$, …