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single-walled-carbon
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Chemical Modification of Glassy Carbon Electrode by Carbon Nanostructures/Conductive Polymers Composites and Its Application in The Study of Electrochemical Behaviour and Determination of Salbutamol and Isoprenaline
, M.Sc. Thesis Sharif University of Technology ; Shahrokhian, Saeed (Supervisor)
Abstract
In the first part of thesis, the electropolymerization of pyrrole was performed in the presence of new coccine (NC) as a dopant anion on the surface of the electrode precoated with SWCNT. The modified electrode was used to study the voltammetric response of salbutamol (SAL). The results showed a remarkable increase in the anodic peak current of SAL in comparison to the bare GCE. The surface morphology PPY/CNT/GCE was thoroughly characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. Under the optimized analysis conditions, the modified electrode showed two linear dynamic ranges of 0.02 – 0.1 μM and 0.1-10 μM with a detection limit of 6 nM for the...
Simulation of Fluid Flow in Nonstraight Nanochannels
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Ali (Supervisor)
Abstract
Understanding the flow of liquids and particularly water in nanochannels is important for scientific and technological applications, such as for filtration and drug delivery. In this study, we perform molecular dynamics simulations to investigate the transfer of single-file water molecules across straight or nonstraight single-walled carbon nanotubes (SWCNTs). In contrast with the macroscopic scenario, the nonstraight nanostructure can increase the water permeation. Remarkably, compared with the straight SWCNT, the nonstraight SWCNT with the minimal bending angle of 30° in the simulations can enhance the water transport up to 3.9 times. Also increasing length and diameter of carbon nanotubes...
Nonlinear dynamic analysis of SWNTs conveying fluid using nonlocal continuum theory
, Article Structural Engineering and Mechanics ; Volume 66, Issue 5 , 10 June , 2018 , Pages 621-629 ; 12254568 (ISSN) ; Mousavi, T ; Bahai, H ; Sharif University of Technology
Techno Press
2018
Abstract
By employing the nonlocal continuum field theory of Eringen and Von Karman nonlinear strains, this paper presents an analytical model for linear and nonlinear dynamics analysis of single-walled carbon nanotubes (SWNTs) conveying fluid with different boundary conditions. In the linear analysis the natural frequencies and critical flow velocities of SWNTs are computed. However, in the nonlinear analysis the effect of nonlocal parameter on nonlinear dynamics of cantilevered SWNTs conveying fluid is investigated by using bifurcation diagram, phase plane and Poincare map. Numerical results confirm existence of chaos as well as a period-doubling transition to chaos. Copyright © 2018 Techno-Press,...
Bridged single-walled carbon nanotube-based atomic-scale mass sensors
, Article Applied Physics A: Materials Science and Processing ; Volume 122, Issue 8 , Volume 122, Issue 8 , 2016 ; 09478396 (ISSN) ; Shaat, M ; Abdelkefi, A ; Sharif University of Technology
Springer Verlag
Abstract
The potentials of carbon nanotubes (CNTs) as mechanical resonators for atomic-scale mass sensing are presented. To this aim, a nonlocal continuum-based model is proposed to study the dynamic behavior of bridged single-walled carbon nanotube-based mass nanosensors. The carbon nanotube (CNT) is considered as an elastic Euler–Bernoulli beam with von Kármán type geometric nonlinearity. Eringen’s nonlocal elastic field theory is utilized to model the interatomic long-range interactions within the structure of the CNT. This developed model accounts for the arbitrary position of the deposited atomic-mass. The natural frequencies and associated mode shapes are determined based on an eigenvalue...
A numerical study on the influence of interface recombination on performance of carbon nanotube/GaAs solar cells
, Article Optical and Quantum Electronics ; Volume 48, Issue 8 , 2016 ; 03068919 (ISSN) ; Ghaffari, S ; Rezaei, E ; Sharif University of Technology
Springer New York LLC
Abstract
Carbon nanotubes (CNT) have unique electronic properties and remarkable optical properties. Despite of on layer thickness of CNTs, it has able to absorb photons from visible to far infrared and terahertz. These unique properties lets to create heterojunction devices by semiconductor/CNTs or metal/CNTs junctions e.g. photodiodes, sensor and heterojunction solar cell. The CNTs can play the role of a heterojunction component for charge separation as a high conductive network for charge transport and as a transparent electrode for light illumination and charge collection. The main objective of the present article is to establish a relation between interface recombination and the characteristics...
Biomass-derived wearable energy storage systems based on poplar tree-cotton fibers coupled with binary nickel-cobalt nanostructures
, Article Sustainable Energy and Fuels ; Volume 4, Issue 2 , 2020 , Pages 643-654 ; Unalan, H. E ; Shahrokhian, S ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
We hereby demonstrate symmetric and asymmetric supercapacitors (SSCs and ASCs) based on core/shell-like Ni-Co oxide@cotton//Fe2O3-carbon nanotubes@cotton that are capable of storing a remarkable amount of energy, while retaining a high power density and long cycle life. Hierarchical, porous structures of Ni-Co-O nano-rod (NR) decorated Pd-activated cotton fibers (CFs) were fabricated using an eco-benign hydrothermal method and directly used as the cathode of the supercapacitors. Fe2O3-single-wall carbon nanotube (SWCNT) decorated CFs were employed as anodes of the fabricated ASCs. The assembled Ni-Co-O@cotton//Fe2O3-SWCNTs@cotton based ASCs possessed the benefits of a relatively high energy...
Design of n-tier multilevel interconnect architectures by using carbon nanotube interconnects
, Article IEEE Transactions on Very Large Scale Integration (VLSI) Systems ; Volume 23, Issue 10 , October , 2015 , Pages 2128-2134 ; 10638210 (ISSN) ; Sarvari, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
In this paper, n-tier methodology is developed to design multilevel interconnect architecture of macrocells using single-wall carbon nanotube (SWCNT) bundles. Upper limit of low-bias voltage of SWCNT bundle interconnects is derived and its dependence on temperature, SWCNTs' diameter, and interconnect length is studied. Possibility of using SWCNT bundles as local interconnects at 7.5-nm technology node is discussed, and it is shown that SWCNT bundles with 1 nm diameter cannot be used at the first interconnect metal level. Using Cu and SWCNT bundles, multilevel interconnect architecture of a 7.5-nm ASIC macrocell is designed which reduces the number of metal levels by 27% and power dissipation...
Dual ideal shear strengths for chiral single-walled carbon nanotubes
, Article International Journal of Non-Linear Mechanics ; Volume 120 , 2020 ; mohamadi Shodja, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
By considering a single-walled carbon nanotube (SWCNT) as a two-dimensional elastica obtained from the roll-up of a graphene sheet into a circular tube, the present paper develops a precise well-posed continuum theory for describing the entire torsional behavior of SWCNTs from an initial unloaded state through their ultimate levels of loading. In addition, the proposed approach can capture the dual ideal shear strengths as well as the asymmetrical behavior of chiral tubes with respect to the direction of the applied torsional loading. The theory incorporates a highly nonlinear constitutive equation which provides information about the nanoscopic morphological parameters of the tubes. As it...
Plasmon-induced near-infrared fluorescence enhancement of single-walled carbon nanotubes
, Article Carbon ; Volume 194 , 2022 , Pages 162-175 ; 00086223 (ISSN) ; Tsoulos, T. V ; Sajjadi, S. H ; Antonucci, A ; Wu, S. J ; Tagliabue, G ; Fatmehsari Haghshenas, D ; Boghossian, A. A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Single-walled carbon nanotubes (SWCNTs) emit near-infrared (NIR) fluorescence that is ideal for optical sensing. However, the low quantum yields diminish the sensor's signal-to-noise ratio and limits the penetration depths for in vivo measurements. In this study, we perform a systematic investigation of the plasmonic effects of Ag and Au nanoparticles of various geometries to tune and even enhance the fluorescence intensity of single-stranded DNA-wrapped SWCNTs (ssDNA-SWCNTs). We observe a chirality-dependent NIR fluorescence enhancement that varies with both nanoparticle shape and material, with Au nanorods increasing (7, 5) and (7, 6) chirality emissions by 80% and 60% and Ag nanotriangles...
Scalable, microwave-assisted decoration of commercial cotton fabrics with binary nickel cobalt sulfides towards textile-based energy storage
, Article Electrochimica Acta ; Volume 404 , 2022 ; 00134686 (ISSN) ; Balim, U ; Unalan, H. E ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
High-performance textile-based energy storage systems with high energy and power densities alongside remarkable cyclic life are always at the leading edge of wearable electronics. Herein, commercial cotton fabrics (CCFs) are used as the substrates for the fabrication of ultra-light, high-performance wearable supercapacitors. Hierarchical microstructures of nickel-cobalt sulfide (Ni-Co-S) decorated single-walled carbon nanotubes (SWCNTs) are used as the positive supercapacitor electrodes. Enhanced electrochemical performance with a specific gravimetric capacity of 331 Cg−1 (at a current density of 0.3 Ag−1) is obtained from these Ni-Co-S@SWCNT@CCF electrodes. Besides, composites of graphene...
Vibrational behavior of defective and repaired carbon nanotubes under thermal loading: A stochastic molecular mechanics study
, Article Mechanics of Materials ; Volume 163 , 2021 ; 01676636 (ISSN) ; Moradi, K ; Zeraati, A. S ; Hosseinabadi, H. G ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Carbon nanotubes (CNTs) are promising candidates for high-resolution mass nanosensors owing to their unique vibrational behavior. The structural characteristic (e.g. defect type and density) and working temperature have a significant effect on the natural frequency of CNT-based sensors. Herein, a stochastic approach based on novel finite element and molecular mechanics simulations is implemented to model the effect of temperature and structural characteristics of single-wall CNTs including defects (vacancy defect with different densities) and chirality (zigzag and armchair) on their vibrational behavior. The results show that the vacancy defects exert a significant deterioration of the...
Dynamic stability analysis of single walled carbon nanocone conveying fluid
, Article Computational Materials Science ; Volume 113 , 2016 , Pages 123-132 ; 09270256 (ISSN) ; Noorian, M. A ; Haddadpour, H ; Fotouhi, M. M ; Sharif University of Technology
Elsevier
2016
Abstract
This report aims the study of dynamic stability of single walled carbon nanocone for some axial length conditions and declination angles of 60°, 120°and 240°. For dynamic stability analysis of Single Walled Carbon Nanocone (SWCNC), the mode shapes and frequencies of the carbon nanocone are extracted using the molecular mechanics approach. The mechanical properties of SWCNC were obtained by the Molecular Mechanics (MM) method. The obtained parameters are used for extraction of the conical shell virtual model of nanocone with the same dimensions. The equations of coupled fluid-structural dynamics of SWCNC are derived using the modal expansion for the structural displacements of the conical...
Buckling and vibration analysis of a pressurized CNT reinforced functionally graded truncated conical shell under an axial compression using HDQ method
, Article Computer Methods in Applied Mechanics and Engineering ; Volume 303 , 2016 , Pages 75-100 ; 00457825 (ISSN) ; Asadi, H ; Wang, Q ; Sharif University of Technology
Elsevier
2016
Abstract
The present research deals with bifurcation and vibration responses of a composite truncated conical shell with embedded single-walled carbon nanotubes (SWCNTs) subjected to an external pressure and axial compression simultaneously. The distribution of reinforcements through the thickness of the shell is assumed to be either uniform or functionally graded. The equations of motion are established using Green-Lagrange type nonlinear kinematics within the framework of Novozhilov nonlinear shell theory. Linear membrane prebuckling analysis is conducted to extract the prebuckling deformations. The stability equations are derived by applying the adjacent equilibrium criterion to the prebuckling...
Stability of single-walled carbon nanopeapods under combined axial compressive load and external pressure
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 41, Issue 3 , 2009 , Pages 513-517 ; 13869477 (ISSN) ; Naghdabadi, R ; Sharif University of Technology
Elsevier
2009
Abstract
In this paper, the axial stability of single-walled carbon nanopeapods is studied based on an elastic continuum shell model. In order to model the non-bonded van der Waals interactions between host carbon nanotube and guest fullerenes, an equivalent pressure distribution is proposed and incorporated in the model. Deriving an explicit equation for the determination of critical axial load, it is concluded that the axial stability of a single-walled carbon nanopeapod is less than that of a carbon nanotube under otherwise identical conditions. In addition, it is shown that applying external pressure to the carbon nanopeapod decreases the axial compressive stability through reducing the critical...
The effect of Pd addition to Fe as catalysts on growth of carbon nanotubes by TCVD method
, Article Applied Surface Science ; Volume 254, Issue 20 , 15 August , 2008 , Pages 6416-6421 ; 01694332 (ISSN) ; Reyhani, A ; Iraji zad, A ; Sharif University of Technology
Elsevier
2008
Abstract
The effects of Pd addition to Fe (Pd/Fe = 0, 2.5/7.5, 5/5, 7.5/2.5 and 1) and growth temperatures (920 and 970 °C) on density, diameter and growth mode of carbon nanotubes (CNTs) have been studied. SEM observations and TG analyses confirmed that the CNT yields depend on Pd/Fe ratios as (7.5/2.5) > (5/5) > Pd > (2.5/7.5) > Fe at both growth temperatures. TEM data showed that addition of Pd results in tip growth mode. From Raman spectroscopy data, the order of samples' structural quality (I G /I D ratio) are Fe > Pd/Fe (2.5/7.5) > (5/5) > (7.5/2.5) > Pd and the I G /I D ratios increase by decreasing the growth temperature. Films with higher concentration of Fe (Pd/Fe = 0, 2.5/7.5) contain some...
Free vibrations analysis of carbon nanotubes resting on winkler foundations based on nonlocal models
, Article Physica B: Condensed Matter ; Volume 484 , 2016 , Pages 83-94 ; 09214526 (ISSN) ; Torkaman Asadi, M. A ; Firouz Abadi, R. D ; Kouchakzadeh, M. A ; Sharif University of Technology
Elsevier
Abstract
In the present study, free vibrations of single walled carbon nanotubes (SWCNT) on an elastic foundation is investigated by nonlocal theory of elasticity with both beam and shell models. The nonlocal boundary conditions are derived explicitly and effectiveness of nonlocal parameter appearing in nonlocal boundary conditions is studied. Also it is demonstrated that the beam model is comparatively incapable of capturing size effects while shell model captures size effects more precisely. Moreover, the effects of some parameters such as mechanical properties, foundation stiffness, length and radius ratios on the natural frequencies are studied and some conclusions are drawn
Thermal buckling analysis of bridged single walled carbon nanotubes using molecular structural mechanics
, Article Journal of Applied Physics ; Volume 117, Issue 11 , 2015 ; 00218979 (ISSN) ; Badri Kouhi, E ; Sharif University of Technology
American Institute of Physics Inc
2015
Abstract
This paper is concerned with the stability analysis of bridged single walled carbon nanotubes (SWCNT) under temperature changes. A molecular structural mechanics model is utilized to investigate the free vibration frequencies and thermal buckling of SWCNT. In comparison with most of the previous studies, a temperature-variable thermal-expansion-coefficient is used that is negative under a certain temperature. Also thermal variation of Young's modulus of the CNTs is considered. Several studies are performed to investigate the critical temperature change due to heating and cooling of SWCNTs with different chiralities and slenderness ratios and the stability boundaries are determined
Site-specific protein conjugation onto fluorescent single-walled carbon nanotubes
, Article Chemistry of Materials ; Volume 32, Issue 20 , 2020 , Pages 8798-8807 ; Wu, S. J ; Rahnamaee, S. Y ; Schuergers, N ; Boghossian, A. A ; Sharif University of Technology
American Chemical Society
2020
Abstract
Semiconducting single-walled carbon nanotubes (SWCNTs) are among the few photostable optical emitters that are ideal for sensing, imaging, drug delivery, and monitoring of protein activity. These applications often require strategies for immobilizing proteins onto the nanotube while preserving the optical properties of the SWCNTs. Site-specific and oriented immobilization strategies, in particular, offer advantages for improving sensor and optical signaling responses. In this study, we demonstrate site-specific protein immobilization of a model of enhanced yellow fluorescent protein with a single engineered cysteine residue, using either single-stranded DNA or a pyrene-containing linker to...
Free vibrations of single walled carbon peapods
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Vol. 56 , February , 2014 , pp. 410-413 ; Hojjati, M ; Rahmanian, M ; Sharif University of Technology
Abstract
In this paper the free vibration of single walled carbon nanopeapods encapsulating C60 molecules is considered. The nanopeapod is embedded in an elastic medium and clamped at both ends. The Euler-Bernoulli beam model is used for the carbon nanotube and the C60 molecules are considered as lumped masses attached to the beam. Based on the nonlocal elasticity theory the governing equation of motion is derived and the resonance frequencies of the nanopeapod are obtained. The effects of small scale, foundation stiffness and ratio of the fullerenes' mass to the nanotube's mass on the frequencies are studied and some conclusions are drawn
Transversal thermal transport in single-walled carbon nanotube bundles: Influence of axial stretching and intertube bonding
, Article Journal of Chemical Physics ; Volume 139, Issue 18 , 2013 ; 00219606 (ISSN) ; Tafazzoli, M ; Böhm, M. C ; Alaghemandi, M ; Sharif University of Technology
2013
Abstract
Using reverse nonequilibrium molecular dynamics simulations the influence of intermolecular bridges on the thermal conductivity (λ) in carbon nanotube (CNT) bundles has been investigated. The chosen cross linkers (CH 2, O, CO) strengthen the transversal energy transport relative to the one in CNT bundles without bridges. The results showed that λ does not increase linearly with the linker density. The efficiency of the heat transport is determined by the number of linkers in the direction of the heat flux, the type of the linker, and their spatial ordering. The influence of a forced axial stress on the transversal λ has been also studied. The observed λ reduction with increasing axial...