Begell House Inc.
Nanoscience and Technology: An International Journal
NST
2572-4258
1
2
2010
GAS FLOW AND DIFFUSION IN NANO-SIZED CAPILLARIES AND POROUS BODIES
99-125
10.1615/NanomechanicsSciTechnolIntJ.v1.i2.10
V. M.
Zhdanov
Moscow Institute of Engineering Physics, 31 Kashirskoe Highway 115409 Moscow, Russia
Vjacheslav
Roldughin
A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninskii Ave., 119991, Moscow, Russia
gas mixture flow
non-equilibrium thermodynamics
kinetic theory of gases
Knudsen regime
thermal slip
viscous slip
diffusion slip
capillary
porous media
dusty-gas model
diffusion pressure effect
gas mixture separation
Kinetic effects related to flows of gases and gas mixtures in capillaries and porous bodies are discussed. The models of porous media and the methods for calculation of kinetic coefficients are described. Much attention has been paid to the dusty-gas model. Results of calculation of the kinetic coefficients for small and large values of the Knudsen number are presented with due account for incomplete accommodation of molecules on the surfaces of capillary walls. Special features of gas flows in ultra-fine channels and the effects related to the action of surface forces, surface diffusion, entrainment of gases by phonons and quasi-one-dimensionality of gas flows have been considered. The effects of the asymmetry of gas transport through multilayer membranes have been discussed.
ATOM-SCALE MODELING OF THE CHEMICAL COMPOSITION AND SURFACE MODIFICATION IMPACT ON THE STRUCTURAL, ENERGY, AND STRENGTH PROPERTIES OF NANOCOMPOSITES
127-149
10.1615/NanomechanicsSciTechnolIntJ.v1.i2.20
Yuri G.
Yanovsky
Institute of Applied Mechanics, Russian Academy of Sciences, 7 Leningradsky
Ave., Moscow, 125040, Russia
E. A.
Nikitina
Institute of Applied Mechanics, Russian Academy of Sciences, Moscow, 119991, Russia
Yulia N.
Karnet
Institute of Applied Mechanics, Russian Academy of Sciences,7 Leningradsky Ave., Moscow, 125040, Russia
quantum-chemical and quantum-mechanical modeling
mechanical chemistry
nanocomposites
carbon nanotubes
stress-strain state
molecular friction
interface
surface modification
strength characteristics
The objects of the present study were nanocomposites consisting of a polymer matrix and a nanosized filler, as well as their structural, energy and strength characteristics. The aim of the study was to investigate the mechanical properties of the nanocomposites on the atom-scale level in the framework of quantum-chemical and quantum-mechanical methods. In carrying on this work, both individual components of nanocomposites and the boundary layers between the nanocomposite components were modeled and their microscopic structural and mechanical properties on mechanical deformation (tension) and friction were calculated, with the use of the approximation of the microscopic deformation coordinate and of the cluster approach. Calculations were carried out in a parallel regime. As a result of the study microscopic mechanisms determining the deformation and friction in nanocomposites have been proposed. It was shown in which way the structure and modification of the surface of the nanocomposite components affect their structure and deformation properties. A method of computer selection of the components of nanocomposites with improved strength characteristics has been suggested.
MATHEMATICAL MODEL OF FLUID FLOW IN NANOCHANNELS
151-168
10.1615/NanomechanicsSciTechnolIntJ.v1.i2.30
D. A.
Indeitsev
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
A. K.
Abramyan
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
N. M.
Bessonov
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
L. V.
Mirantsev
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
nanochannel
Couette and Poiseuille flows
two-phase medium
New equations that describe the behavior of fluids in nanochannels and take into account the molecular structure of the fluid and results of real and numerical experiments are presented. The Couette and Poiseuille flows are considered. The results obtained show the possibility of describing structural transformations in thin layers by the continuum mechanics methods. New degrees of freedom of the material are introduced via the second continuum that makes up for the role of the forming new phase of state. In the models considered the properties of the new phase are determined by the effect of rigid boundaries with a different structure.
BEHAVIOR OF FLUID IN PLANE NANOCHANNELS WITH DIFFERENT BOUNDARY WALLS
169-186
10.1615/NanomechanicsSciTechnolIntJ.v1.i2.40
A. K.
Abramyan
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
L. V.
Mirantsev
Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
nanochannel
face-centered cubic lattice
molecular dynamic simulation
Couette flow
The article presents the study of an equilibrium structure of fluid and the Couette shear flow in a plane nanochannel with solid crystal walls whose atoms are in the nodes of the face-centered cubic lattice. The study is conducted by molecular dynamics simulation. The following cases are considered: 1) the both walls have the same lattices with a period coinciding with the characteristic radius σ of the model Lennard–Jones interaction between the fluid particles; 2) the both walls have a face-centered cubic structure with a period half as much as the characteristic radius of interparticle interaction in fluid; 3) a period of the face-centered cubic lattice of one of the nanochannel walls coincides with σ whereas that of the other wall is less by half. The profiles of fluid density in the equilibrium state, the profiles of fluid flow velocity, and the forces acting on solid boundary walls in the Couette shear flow are calculated for the three cases mentioned. It is shown that the structure of motionless fluid in a nanochannel as well as the obtained flow velocity profiles and the forces acting on the walls strongly depend on the structure of the both boundary walls and on the distance between them.