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In this paper, sandwich structures for the separation of gas mixtures are considered. As a result, two types of structures were created and tested: a model complex structure based on a carbon nanotube and a graphene sheet, which consisted of 360 carbon atoms and a sandwich structure composed of a graphene sheet and two parallel carbon nanotubes. The results show that some materials collected from such cell structures can potentially be used for the separation of methane-helium mixtures. The results of calculations for methane and helium are presented.

The present paper deals with permeability of the low-temperature phase of a fullerite using molecular dynamics methods. A discrete model of the material based on “atom−atom” interactions between penetrating components and nodes of the fullerene crystal structure is considered. For the purpose of saving calculation time, when collecting statistical data on passage of molecules and atoms through the porous material under consideration, we found a centrally symmetric distribution of the fullerene action energy and constructed a model of the material based on “smoothed” fullerene particles. The calculations determined permeability of a fullerite membrane containing up to ten planar lattices of the crystal structure. The selectivity factor of the considered membrane, with respect to other components of natural gas is also determined.

In this paper we have considered two versions of elementary cells for creating a nanomembrane, which will be used to separate natural gas into different gas components. Calculated trajectories of helium atoms and methane molecules interacting with elementary structural units of the membrane are presented. The model is based on a discrete approach to describe the interaction of a structure with atoms and molecules.

We consider a layer of open nanotubes identically oriented in space. We investigate permeability of a nanoporous carbon system for a regular triangular packing of tubes. Curves defining layer permeability depending on the degree of spatial proximity of tubes are constructed.

This paper investigates the ability of a test molecule to overcome the energy barrier being in the gap between spherical nanoparticles. Three particles make a primitive structural element of composite porous material. The ability of molecules to converge with nanoparticles and then to move through more powerful repulsion field defines the filtration properties of porous materials. This paper presents the investigation of carbon nanoparticles and molecules of helium and methane bombarding them. Calculations proved that methane molecules can not get through three particles if the gap equals to 3.5 nm. For helium molecules this value makes 1.02 nm. These gaps remain the same when the size of nanoparticles increases. Therefore filters for helium separated from natural gas are to have nanopores within the range from 1.02 nm to 3.5 nm.