Molecular Dynamics Simulations of Carbon Nanotubes in Liquid Flow - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Molecular Dynamics Simulations of Carbon Nanotubes in Liquid Flow write by Wenzhong Tang. This book was released on 2007. Molecular Dynamics Simulations of Carbon Nanotubes in Liquid Flow available in PDF, EPUB and Kindle. Molecular dynamics (MD) simulation method is used to simulate the dynamics of nanotubes in liquid flow. This study was motivated by our experimental work on the fabrication and mechanical properties characterization of multi-walled carbon nanotube(MWNT)-high density polyethylene (HDPE) composites fabricated by a melt processing method. SEM and TEM pictures show that the nanotubes are dispersed in the polymer matrix in small aggregates, the size of which decrease with the shearing strength in the suspension. Three types of behaviors are addressed. First, a high aspect ratio nanotube is modeled as a flexible fiber and its dynamics in simple shear flow are simulated by coupling flexible fiber dynamics based on continuum mechanics, with drag forces on the nanotube obtained from MD simulations. Results show that curved nanotubes in simple shear flow become straight and aligned along the shearing direction. Calculations also show that the viscosity of a dilute nanotube suspension increases with nanotube aspect ratio (Ar) and volume fraction (V f). For Ar = 400 and V f =0.708%, the suspension viscosity is two orders higher than the suspending liquid, which is comparable to reported viscosity measurements. The results also show that suspension viscosity decreases as the initial curvature of the nanotube increases. Second, Dynamics of a short nanotube (Ar
Molecular Dynamics Simulations of Liquid Flow in and Around Carbon Nanotubes
Molecular Dynamics Simulations of Liquid Flow in and Around Carbon Nanotubes - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Molecular Dynamics Simulations of Liquid Flow in and Around Carbon Nanotubes write by William David Nicholls. This book was released on 2012. Molecular Dynamics Simulations of Liquid Flow in and Around Carbon Nanotubes available in PDF, EPUB and Kindle. The advent of carbon nanotube (CNT) synthesis has created exciting new oppor- tunities in fluid dynamic applications as the fluid behaviour can deviate signifi- cantly from conventional continuum expectations. CNTs indicate major potential in nanotechnologies such as seawater desalination. Molecular dynamics (MD) is often the numerical method of choice for fluid dynamics at the nanoscale due to its high level of detail and accuracy. Using the "controllers" of Borg et al.[1], we are able to shrink the computa- tional domain required for molecular dynamic simulations of the external flow of liquid argon past a CNT and significantly increase the simulation's computational efficiency. We apply three pressure differences across a CNT membrane carrying liquid argon, and compare the results of the pressure-driven flow through the nanotube with hydrodynamic predictions and Navier-Stokes solutions. We find that both fail to accurately predict flow behaviour in this problem. Non-equilibrium molecular dynamics simulations are then used to investigate water transport through (7,7) CNTs, investigating how changing the CNT length affects the internal flow dynamics. We show that, under the same applied pressure difference, an increase in CNT length has a negligible effect on the resulting mass flow rate and fluid flow velocity. Axial profiles of fluid properties demonstrate that entrance and exit effects are significant in the transport of water along CNTs. Large viscous losses in these entrance/exit regions lead into central "developed" regions in longer CNTs where the flow is effectively frictionless. Finally, we investigate how changing the number of structural defects in the wall of a (7,7) single-wall carbon nanotube (CNT) affects the water transport and internal fluid dynamics. Structural defects are modelled as vacancy sites (missing carbon atoms). We find that, while fluid flow rates exceed continuum expectations, increasing numbers of defects lead to significant reductions in fluid velocity and mass flow rate. The inclusion of such defects disrupts the nearly- frictionless water transport commonly attributed to CNTs. The results presented in this thesis are crucial in the development of future nanotechnologies such as CNT membranes for selective material separation.
Fluid Flow Through Carbon Nanotubes
Fluid Flow Through Carbon Nanotubes - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Fluid Flow Through Carbon Nanotubes write by Michael Avon. This book was released on 2009. Fluid Flow Through Carbon Nanotubes available in PDF, EPUB and Kindle. "In this thesis, the flow of fluids through carbon nanotubes was investigated in order to get a better understanding of the unique properties and phenomena of nanofluidics. The previous modeling and simulation efforts were based on diffusion of atoms or molecules that were thrown to the nanotubes with initial velocities. Here, we present molecular dynamics simulations of carbon nanotubes that were embedded in liquid argon. The fluid was pushed through the nanotubes using a moving wall piston of graphene. Single-walled, double-walled, rigid and relaxed nanotubes in different diameters were considered. In order to achieve more continuous flow of fluid through the nanotube, several rounds of pumping were simulated. Pressure difference in different regions was analyzed."--Abstract.
Molecular Dynamics Studies of Water Flow in Carbon Nanotubes
Molecular Dynamics Studies of Water Flow in Carbon Nanotubes - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Molecular Dynamics Studies of Water Flow in Carbon Nanotubes write by Alexander Douglas Marshall. This book was released on 2012. Molecular Dynamics Studies of Water Flow in Carbon Nanotubes available in PDF, EPUB and Kindle. We present classical molecular dynamics (MD) simulations providing insight into the behaviour of water. We focus on confined water, the properties of which are often significantly di erent from the properties of bulk water. First, we performed several simulations investigating the handling of long-range interactions in GROMACS [34], a MD simulation package. Selection of simulation protocols such as handling of long-range interactions is often overlooked, sometimes to the significant detriment of the final result [10, 79, 80]. Ensuring that the chosen simulation protocols are appropriate is a critical step in computer simulations. Second, we performed MD simulations where water flowed between two reservoirs connected by a carbon nanotube. We analyzed 10 simulations where two types of changes were made to induce flow: The removal of water molecules from one reservoir and the addition of NaCl to one reservoir at one of two concentrations. We study the e ects of these changes in isolation, cooperation and competition.
Carbon Nanotubes as Nanodelivery Systems
Carbon Nanotubes as Nanodelivery Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Carbon Nanotubes as Nanodelivery Systems write by Melvin Choon Giap Lim. This book was released on 2013-05-18. Carbon Nanotubes as Nanodelivery Systems available in PDF, EPUB and Kindle. This book showcases the application of carbon nanotubes as nanodelivery systems for copper atoms, using molecular dynamics simulations as a means of investigation. The nanodelivery system of the carbon nanotube presents the possible usage of the carbon structure in many areas in the future. This book is comprehensive and informative, and serves as a guide for any reader who wishes to perform a molecular dynamics simulation of his own and to conduct an analytical study of a molecular system.
