Zeolite-templated Carbon Network: A Beta Zeolite Case Study

MRS Advances ◽  
2020 ◽  
Vol 5 (14-15) ◽  
pp. 751-756 ◽  
Author(s):  
Eliezer F. Oliveira ◽  
Leonardo D. Machado ◽  
Ray H. Baughman ◽  
Douglas S. Galvao
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Beta Zeolite ◽  
Beta Zeolites ◽  
Preliminary Study ◽  
The One ◽  
Dynamics Simulations ◽  
Carbon Nanotube Networks ◽  
Carbon Network

ABSTRACTIn this work, we report a preliminary study, based on molecular dynamics simulations, about 3D carbon nanotube networks that could be formed inside the beta zeolites. We investigated their structural stability and mechanical properties. Our results show that from all possible carbon nanotubes that can be embedded inside the channels of the beta zeolite, the one with chirality (6,0) is the most stable. Using the carbon nanotube (6,0), it is possible to build 3D structures with both all (higher density) and only partially (lower density) filled zeolite channels. Under tensile uniaxial force, the 3D low-density carbon nanotube networks are anisotropic and can be stretched along the direction in which all nanotubes are perpendicular up to 130% of strain without fracture. Also, the porosity and network stiffness can be tuned depending on the amount of carbon nanotubes filling the channels of the zeolites.

Electronic and Mechanical Properties of Super Carbon Nanotube Networks

2006 ◽  
Vol 963 ◽  
Author(s):  
Vitor R. Coluci ◽  
Socrates O. Dantas ◽  
Ado Jorio ◽  
Douglas s Galvao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Tight Binding ◽  
Deformation Mechanisms ◽  
Different Types ◽  
Dynamics Simulations ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanotube Networks ◽  
Main Deformation

ABSTRACTEletronic and mechanical properties of ordered carbon nanotube networks are studied using molecular dynamics simulations and tight-binding calculations. These networks are formed by single walled carbon nanotubes (SWNT) regularly connected by junctions. The use of different types of junctions (“Y”-, “X”-like junctions, for example) allows the construction of networks with different symmetries. These networks can be very flexible and the elastic deformation was associated with two main deformation mechanisms (bending and stretching ) of the constituents SWNTs. Rolling up the networks, “super” carbon nanotubes can be constructed. These super-tubes share some of the main electronic features of the SWNT which form them but important changes are predicted (e.g. reduction of bandgap value). Simulations of their deformations under tensile stress have revealed that the super-tubes are softer than the corresponding SWNT and that their rupture occur in higher strain values.

scholarly journals Growth and structural discrimination of cortical neurons on randomly oriented and vertically aligned dense carbon nanotube networks

2014 ◽  
Vol 5 ◽  
pp. 1575-1579 ◽  
Author(s):  
Christoph Nick ◽  
Sandeep Yadav ◽  
Ravi Joshi ◽  
Christiane Thielemann ◽  
Jörg J Schneider
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Cortical Neurons ◽  
Three Dimensional ◽  
Vertically Aligned Carbon Nanotubes ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned ◽  
The Individual ◽  
Carbon Nanotube Networks ◽  
Communication Paths

The growth of cortical neurons on three dimensional structures of spatially defined (structured) randomly oriented, as well as on vertically aligned, carbon nanotubes (CNT) is studied. Cortical neurons are attracted towards both types of CNT nano-architectures. For both, neurons form clusters in close vicinity to the CNT structures whereupon the randomly oriented CNTs are more closely colonised than the CNT pillars. Neurons develop communication paths via neurites on both nanoarchitectures. These neuron cells attach preferentially on the CNT sidewalls of the vertically aligned CNT architecture instead than onto the tips of the individual CNT pillars.

scholarly journals Free energy surface of initial cap formation in carbon nanotube growth

2021 ◽  
Author(s):  
Satoru Fukuhara ◽  
Yasushi Shibuta
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Carbon Nanotube ◽  
Energy Surface ◽  
Catalyst Surface ◽  
Important Process ◽  
Free Energy Surface ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth ◽  
Carbon Network

Initial cap formation is an important process of carbon nanotubes (CNTs) growth where hexagonal carbon network is lifted off from the catalyst surface. In this study, free energy surface (FES)...

scholarly journals Carbon Nanotubes: Selective Breakdown of Metallic Pathways in Double-Walled Carbon Nanotube Networks (Small 1/2015)

Small ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Allen L. Ng ◽  
Yong Sun ◽  
Lyndsey Powell ◽  
Chuan-Fu Sun ◽  
Chien-Fu Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Carbon Nanotube Networks

scholarly journals Surface Energy-Controlled Self-Collapse of Carbon Nanotube Bundles With Large and Reversible Volumetric Deformation

2013 ◽  
Vol 80 (4) ◽  
Author(s):  
Yuan Cheng ◽  
Nicola Maria Pugno ◽  
Xinghua Shi ◽  
Bin Chen ◽  
Huajian Gao
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Surface Energy ◽  
Nanotube Bundles ◽  
Volumetric Deformation ◽  
Equilibrium Configurations ◽  
Simulation Results ◽  
Dynamics Simulations ◽  
Effect Of Surface

Molecular dynamics simulations are performed to investigate the effect of surface energy on equilibrium configurations and self-collapse of carbon nanotube bundles. It is shown that large and reversible volumetric deformation of such bundles can be achieved by tuning the surface energy of the system through an applied electric field. The dependence of the bundle volume on surface energy, bundle radius, and nanotube radius is discussed via a dimensional analysis and determined quantitatively using the simulation results. The study demonstrates potential of carbon nanotubes for applications in nanodevices where large, reversible, and controllable volumetric deformations are desired.

The Unravelling of Open-Ended Single Walled Carbon Nanotubes Using Molecular Dynamics Simulations

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Tarek Ragab ◽  
Cemal Basaran
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulations ◽  
Single Walled Carbon Nanotubes ◽  
Atomic Chain ◽  
Single Walled Carbon ◽  
Different Temperatures ◽  
Dynamics Simulations ◽  
Walled Carbon Nanotubes

The unravelling of (10, 10) and (18, 0) single-walled carbon nanotubes (SWCNTs) is simulated using molecular dynamics simulations at different temperatures. Two different schemes are proposed to simulate the unravelling; completely restraining the last atom in the chain and only restraining it in the axial direction. The forces on the terminal atom in the unravelled chain in the axial and radial directions are reported till the separation of the atomic chain from the carbon nanotube structure. The force-displacement relation for a chain structure at different temperatures is calculated and is compared to the unravelling forces. The axial stresses in the body of the carbon nanotube are calculated and are compared to the failure stresses of that specific nanotube. Results show that the scheme used to unravel the nanotube and the temperature can only effect the duration needed before the separation of some or all of the atomic chain from the nanotube, but does not affect the unravelling forces. The separation of the atomic chain from the nanotube is mainly due to the impulsive excessive stresses in the chain due to the addition of a new atom and rarely due to the steady stresses in the chain. From the simulations, it is clear that the separation of the chain will eventually happen due to the closing structure occurring at the end of the nanotube that would not be possible in multiwalled nanotubes.

Aligned fluorinated single-walled carbon nanotubes as a transmission channel towards attenuation of broadband electromagnetic waves

2018 ◽  
Vol 6 (35) ◽  
pp. 9399-9409 ◽  
Author(s):  
Yang Liu ◽  
Yichun Zhang ◽  
Cheng Zhang ◽  
Benyuan Huang ◽  
Xu Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electromagnetic Waves ◽  
Single Walled Carbon Nanotubes ◽  
Transmission Channel ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Strong Electrostatic Interaction ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanotube Networks

Highly fluorinated single-walled carbon nanotubes tend to be oriented under stress due to strong electrostatic interaction allowing directional propagation and then effective attenuation of electromagnetic waves by pristine single-walled carbon nanotube networks.

scholarly journals Virtual Learning Environments as a Remedy for Universities Against the COVID-19 Pandemic Crisis

2021 ◽  
Vol 3/2021 (93) ◽  
pp. 122-137
Author(s):  
Tomasz Eisenbardt ◽  
Keyword(s):  
Scientific Literature ◽  
Virtual Learning ◽  
Virtual Learning Environment ◽  
Organizational Changes ◽  
Common Features ◽  
Preliminary Study ◽  
The One ◽  
The University ◽  
Short Time

Purpose: The aim of the paper is to assess the level of interest in the Virtual Learning Environment (VLE) during and before the pandemic, as well as to identify and compare solutions implemented at selected Polish universities during the COVID-19 pandemic. Research methodology: The preliminary study was based on bibliometric analysis. The frequency of the VLE notion in the scientific literature was verified. Then a case study was applied. Six universities in Poland were analyzed, which had to make radical organizational changes in a short time, allowing them to conduct classes with students almost exclusively remotely. Findings: The conducted analysis led to the identification of significant similarities in the procedures undertaken and organizational changes of the universities described. Some variation has been observed in terms of the software used that builds the university’s VLE. Research limitations: Only cases of universities in Poland have been described. The choice of the university was intentional. Value: The value of the paper is to draw attention to: on the one hand, the versatility of the VLE, and on the other, certain common features that university VLEs should have in order to ensure the work of the university (and other institutions dealing with education) in a crisis situation.

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