CONDITIONS FOR CREATING THIN LIQUID LAYERS AT THE CONTACT SURFACE OF TWO OTHER LIQUIDS Agnieszka...
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CONDITIONS FOR CREATING THIN LIQUID LAYERS AT THE CONTACT SURFACE OF TWO OTHER LIQUIDS Agnieszka Słowicka Zbigniew A. Walenta Institute of Fundamental Technological Research Polish Academy of Sciences
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Transcript of CONDITIONS FOR CREATING THIN LIQUID LAYERS AT THE CONTACT SURFACE OF TWO OTHER LIQUIDS Agnieszka...
CONDITIONS FOR CREATING THIN LIQUID LAYERS
AT THE CONTACT SURFACE OF TWO OTHER LIQUIDS
Agnieszka Słowicka Zbigniew A. Walenta
Institute of Fundamental Technological Research
Polish Academy of Sciences
Aim- Nanomaterials of structure as shown
Water
OilOil
Oil Water
The emulsion with thin layers of third substanceat the surface between oil and water
The structure of nanomaterial after removingwater and oil
Molecular Dynamics Simulation
Liquid – an ensemble of molecules
Interaction between molecules
Electrostatic interaction van der Waals interaction
Coulomb potential Lennard - Jones potential
The program „Moldy” by Keith Refson used for simulation.
Models of molecules and interactions
])()[()( 612 rrrU
Diagram of the Lennard-Jones potential
Molecule of water Molecule of oil Molecule of the third fluid
180 amu+
H
O16 amu
1 amu+
H
+23 amu
Na +16 amu
O
180 amu
O
OilOil
180 amu
Oil Water
Parameters of the Lennard-Jones potential
+
H
O
+
H
18 amu
woow εεε
057199.0oε 2407.3oσ 57199.0wε 2407.3wσ
163803.0owε 2407.3owσ
2/)( woow σσσ
t = 0 ps t = 9 ps t = 13 ps
Molecules of water = 1000
Diameter of the droplet ~A 32
Formation of water droplet in vacuum
Oscilation period = 26 ps ~diameter of oil droplet
average speed of molecules
Simulation of emulsification process
t = 0 ps
t = 5 ps t = 13 ps
Temperature = 300 K
Molecules of water = 7000Molecules of oil = 1000
Diameter of oil droplet ~ A 32
t = 0 ps
t = 48 ps
Temperature = 300 K
Molekules of water = 2614Molekules of oil = 257
Molecules of soap = 252 Diameter of oil droplet ~
A 20
Simulation of three liquids
t = 123 ps
•The molecular dynamics seems to be the best tool to simulate physical processes on a nanoscale in liquids.
•Formation of water droplet in vacuum and oil droplet in water have been simulated successfully.
•The addition of soap, expected to remain at the surface of oil, leads to destruction of oil droplets.
•Now we look for other substances which would stay at the surface of the droplets and would not destroy them.
Conclusions
