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     COLLOQUIUM OF THE COMPUTATIONAL MATERIALS SCIENCE CENTER
                                AND 
           THE DEPARTMENT OF COMPUTATIONAL & DATA SCIENCES
                            (CSI 898-Sec 001)
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  Mechanical Effects of Fluids Adsorption by Nanoporous Materials

                       Gennady Gor
       Center for Computational Materials Science
       Naval Research Laboratory, Washington, DC

In this talk I will focus on two mechanical effects related to fluid
adsorption by porous materials: adsorption-induced deformation and
change of elastic properties of fluids during adsorption. The
development of quantitative theories of these effects will provide the
opportunity to employ them for new sensing technologies and new
approaches for the characterization of nanoporous materials.

Adsorption-induced deformation is a change of shape or volume of a
porous sample during adsorption. It could be either expansion or
contraction, and while the former is well understood, the latter is
still puzzling due to the apparent contradiction with the Gibbs
adsorption equation. I will show how this apparent contradiction can
be resolved by relating the strain of the solid to the change of the
surface stress due to adsorption. I will present the results of the
surface stresses calculations based on ab initio molecular dynamics
simulations.

In the second part of the talk I will focus on the effects of
nanoconfinement on the mechanical properties of the adsorbed fluid.
Recent ultrasonic experiments have shown that the elastic modulus of
argon adsorbed in nanoporous glass noticeably differs from the elastic
modulus of bulk liquid argon. I will present the results of a
molecular modeling study, which explains these experimental
observations and sheds light on possibilities of ultrasonic
investigation of nanoporous materials.
 
                           April 11, 2016
                               4:30 pm
                    Exploratory Hall, room 3301 
                          Fairfax Campus

Refreshments will be served at 4:15 PM.
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Find the schedule at http://www.cmasc.gmu.edu/seminars.htm