Nanocomposites Based on Calcium Alginate and Carbon Nanotubes for Selective Adsorption of Argon from a Mixture with Oxygen

Abstract—Nanocomposites were synthesized on the basis of calcium alginate and carbon nanotubes by the sol–gel method, and their adsorption properties with respect to argon were investigated to separate it from a mixture with oxygen. The adsorbents were characterized using thermogravimetric analysis and scanning electron microscopy (SEM). SEM micrographs of the samples indicated that carbon nanotubes are located on the surface of the alginate matrix. It is shown that the introduction of carbon nanotubes into the structure of nanocomposites led to an increase in the selectivity of these materials with respect to argon. The separation coefficients of the argon–oxygen mixture were calculated as the ratio of the Henry coefficients from the adsorption isotherms of argon and oxygen at 25°C, the maximum value of the separation factor was 1.9.