FIELD: physical chemistry; methods and devices for determination of adsorption and desorption branches of nitrogen adsorption isotherms at 77 K by dynamic method of thermal desorption. SUBSTANCE: Simultaneously, adsorption and desorption branches of adsorption isotherms are determined at 77 K by dynamic method at P/Po changing from 0.001 to 0.999. Device is proposed for realization of this method. Simultaneously, two invert mixtures of helium and nitrogen are prepared at content of nitrogen of from 0.1 to 99.9% by volume and measurements of amount of nitrogen adsorbed at temperature of 77 K and different ratios of P/Po are performed on two specimens of material under test by dynamic method. At discrete increased of P/Po from 0.001 to 0.999, information on adsorption branch of adsorption isotherm is obtained and at discrete decrease of P/Po from 0.999 to 0.001, information on desorption branch of adsorption isotherm is obtained. Thus, specific surfaces, distribution of pores by sizes and other important characteristics of materials under test may be determined on the basis of obtained experimental information through calculations. EFFECT: enhanced efficiency. 15 cl, 1 dwg
