METHOD FOR DETECTING GAS AND STEAM SORPTION ISOTHERMS IN MEMBRANE MATERIALS AND DEVICE FOR IMPLEMENTING IT Russian patent published in 2015 - IPC G01N30/00 

FIELD: chemistry.

SUBSTANCE: determining gas and steam sorption isotherms in membrane materials is ensured by measuring an amount of gas (steam) in the gas phase of a sorption volume. That is followed by gas (steam) sorption with a membrane material at a pre-set partial pressure of the gas (steam) until it completely saturates the membrane material, and gas (steam) desorption by a gas carrier flow in a chromatographic detector. The sorption and desorption are conducted in the isothermal environment in a chromatographic loop attached to an injection valve. Using the derived chromatogram enables calculating the amount of the sorbed gas (steam) $$n_1^{pol},$$ mole, by formula: $$n_1^{\sum }=n_1^G+n_1^{pol},$$ V^Σ,G=V^pol+V^G, $$V^{pol}=\frac{m_{pol}}{{\rho }_{pol}},$$ wherein $$n_1^{\sum },$$ mole that is the total amount of the gas and steam in the sorption volume derived from a chromatogram peak area; $$n_1^G$$ is an amount of the gas or steam in the empty volume of V^G loop filled with the membrane material, and derived from the gas or steam state equation, V^∑,G, cm³, that is the total volume derived from the gas or steam state equation from the preset gas or steam amount in the gas phase of the sorption volume, V^pol, cm³, is an amount of the membrane material; m_pol, g, is a weight of the membrane material in the sorption volume, ρ_pol, g/cm³ that is a density of the membrane material. A device for implementing the given method consists of a gas or steam preparation unit, a detection unit that is a gas chromatograph detector and a sorption-desorption unit in the form of a chromatographic loop attached to a two-way batching cock. The cock is configured to switch into the position for gas or steam sorption in the membrane material and in the position for gas or steam desorption by a gas flow carrier into the detection unit.

EFFECT: simplifying and accelerating the measurements, preventing the change of properties of the membrane materials under heating and cooling down.

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