Abstract:
The simplest example of the porous filtering system is a compacted material obtained by
pressing spherical nanoparticles. Filtration characteristics of this material depend on mobility of
molecules in the field of van der Waals forces.
À one-dimensional wave dynamic problem of the helium molecules motion through the
ultrathin porous layer of compacted diamond nanoparticles is considered. These layers of matter
make a potential barrier obstructing the passage of molecules. The permeability of the layer is
derived by solving the Schrödinger equation.
The calculation technology for integration of the Schrödinger equation is suggested. It is
based on two fundamental numerical solutions of the problem of waves passing through the
barrier of potential forces. A linear combination of these solutions determinates the wave
function. The square of this function is a probability of detecting molecules in a particular place.
Linking this representation of wave function with asymptotic boundary conditions makes it
possible to determine the coefficients of passing and reflecting of molecules from the barrier. The
barrier is the energy of compacted nanoparticles.
This technology provides with results close to the analytical solution in particular cases. This
fact allows to generalize the method to the case of molecular movement through the layer of
nanoparticles and to determine the dependence between permeability and porosity of the layer.