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Green Synthesis of Carbon Nanotubes
Published in Soney C. George, Jacob Philip, Ann Rose Abraham, A. K. Haghi, Carbon Nanotubes for Energy and Environmental Applications, 2023
K. C. Nimitha, Jiji Abraham, Arunima Reghunadhan, Soney C. George, Sabu Thomas
Extensive research has been carried out in CNTs because of their outstanding properties and commercial applications. Remarkable properties of CNTs are derived from the curved sp2 graphene layers by impressing extra quantum confinement and topological constraints in the circumferential track of the cylinders.2 Carbon nanotubes have got excellent electrical, mechanical, electronic, chemical, and optical properties. Carbon–carbon covalent bonds present in CNTs make them excellent thermal conducting material. Youngs modulus of SWCNT is higher than that of the commercial carbon fibers which indicate the high mechanical strength (the C–C covalent bond in CNTs is one of the strongest bonds found in nature) of SWCNT. Carbon nanotubes have remarkable electrical properties—semiconducting, metallic or semimetallic depending on the method of production which controls the degree of graphitization, the diameter of the tube, and the helicity, that is, wrapping angles. Electrical properties of CNTs are structure-dependent, all armchair SWCNTs and one-third of all zigzag nanotubes are metallic, the remaining are semiconducting (Table 11.1).3
Advanced Nanocarbon Materials
Published in Sarika Verma, Raju Khan, Avanish Kumar Srivastava, Advanced Nanocarbon Materials, 2022
Deepshikha Rathore, Umesh K. Dwivedi
Subsequently, Sumio Iijima discovered new carbon nanotube materials in 1991, which exhibited highly efficient electrical, mechanical, and thermal properties. As a consequence, carbon nanotubes have been extensively used in electronic components, energy storage, electrical, chemical, mechanical, and optical applications. More recently, graphene was discovered by Andre Geim and Kostya Novoselov of the University of Manchester in 2004, exhibiting a beautiful single layer of carbon atoms in a lattice structure. The potential applications of graphene, the thinnest and strongest material in the world, were flexible, thin, and lightweight photonic and electric circuits, solar cells, and various chemical, medical, and industrial developments.
Green Synthesized Carbon-Based Nanomaterials: Synthesis and Properties
Published in Shrikaant Kulkarni, Ann Rose Abraham, A. K. Haghi, Renewable Materials and Green Technology Products, 2021
Binila K. Korah, Neena John Plathanam, Anu Rose Chacko, Mamatha Susan Punnoose, Thomas Abraham, Beena Mathew
Carbon nanotubes are an inevitable part of technology with a huge potential of future applications. Green approach is the only answer to solve the dilemma of fossil fuel related source and the pollution it cause to nature. The use of natural resource as precursor and catalyst will not only minimize the cost and utilization of restricted fossil fuels but will also help us to take care of our environment in a more benign way. In this effort, the various synthesis methods employed for the preparation of CNTs involved the common natural precursors used, different green approaches adopted for replacing toxic metal catalysts, and the general properties of CNTs are discussed. The study of properties and applications of CNTs from natural sources is still in progress. Therefore it can be concluded that the CNTs synthesized from green precursors have a very high potential for future applications.
Plethora of Carbon Nanotubes Applications in Various Fields – A State-of-the-Art-Review
Published in Smart Science, 2022
Nidhi Jain, Eva Gupta, Nand Jee Kanu
Carbon nanotubes have the symmetry and unique electronic structure of graphene; nanotubes have a very high current carrying capacity. They are extensively used for speculate materials of the new century and are being used for a number of applications [58] ranging from automobiles to nanometer scale electronics. The electrical properties are useful for saving energy and in turn decrease the use of wood cutting and the use of traditional batteries by providing better electrical materials for future generations [59,60]. Carbon nanotubes provide small size, carbon-based nanoelectronics having high flexibility compared to conservative silicon electronics. Carbon nanotubes have unusual properties because of the low dimensionality [61]. Carbon nanotubes can be used to harness electronics devices, which is helpful in power saving, radiation, hardness, and reduced heat dissipation. Carbon nanotubes can be effectively used to relate the phenomena of photoconductivity, thermoelectricity, and superconductivity [61]. The basic conducting features of a graphene tubule are also known to be dependent on the type of wrapping (chirality) and the diameter (usually, SWNTs possess diameters ranging from 0.4 nm to 2 nm). The CNTs replace traditional batteries such as electrochemical capacitors or super capacitors, which are not only given their miniature size, elevated power density, prolonged for a longer period of time, and high energy density, which decrease the waste disposal to the environment.
A comparative analysis of hybrid nanofluid flow through an electrically conducting vertical microchannel using Yamada-Ota and Xue models
Published in Numerical Heat Transfer, Part A: Applications, 2023
Khalid Abdulkhaliq M. Alharbi, Jawad Ali, Muhammad Ramzan, Seifedine Kadry, Abdulkafi Mohammed Saeed
Carbon nanotubes are cylindrical tubes of carbon atoms that are identified for their strength and high electrical and thermal conductivity. They are one of the strongest and stiffest materials known and have a wide variety of potential applications, which includes electronics, energy storage, and structural materials. There are two main kinds of carbon nanotubes: single-walled nanotubes (SWNTs), which consist of a single layer of carbon atoms, and multiwalled nanotubes (MWNTs), which consist of multiple concentric layers of carbon atoms. Carbon nanotubes can be synthesized using a variety of methods, including chemical vapor deposition and laser ablation. Carbon nanotubes have a number of potential applications due to their unique physical and chemical properties. The carbon nanotubes possess the ensuing potential applications including sensors, electronics, energy storage, drug delivery, filters, and structural materials. Researchers and scientists have shown great interest in exploring varied traits of CNTs in numerous flow problems. Dawar et al. [20] examine an unsteady magnetohydrodynamic nanoliquid flow with CNTs buried, viscous incompressible, and entropy structure in a spinning channel. Khan et al. [21] have quantitatively examined the features of a rotating channel with a lower expanding wall and a CNTs nanofluid squeezing flow in three dimensions. Kumar et al. [22] studied the combined consequences of Hall current with thermal radiative heat flux on a flow of micropolar nanoliquid with immersed CNTs in the double rotating sheets. In recent times, the flow of a nanoliquid containing embedded CNTs in a variety of shapes has been seen in Refs. [23–28].
Thermal stress and magnetic effects on nonlinear vibration of nanobeams embedded in nonlinear elastic medium
Published in Journal of Thermal Stresses, 2020
Sardar S. Abdullah, Shahrokh Hosseini-Hashemi, Nazhad A. Hussein, Reza Nazemnezhad
Nano-sized structural elements are commonly used in nanoelectromechanical systems. The nano-sized elements possess exceptional properties, and several researchers are interested in investigating their behavior and properties. One of these elements is carbon nanotube modeled as nanobeam. The carbon nanotubes are thin cylinders of macromolecules of carbon atoms in a hexagonal arrangement. Several non-classical continuum theories have been adopted for analyzing the nanostructures and nano-sized elements. The effective non-classical continuum theories which are mostly used for analyzing the nano-sized structures are nonlocal stress theory, gradient strain theory, modified couple stress theory, and surface elasticity theory.