METHOD FOR DETERMINING MAXIMUM SIZE OF MEMBRANE PORES Russian patent published in 2015 - IPC G01N15/08 

FIELD: instrumentation.

SUBSTANCE: method for determining maximum size of membrane pores involves installation of a membrane into a cell and filling of the cell with liquid, creation of conditions for ice penetration through the membrane and calculation of a value of maximum size of membrane pores. Methods for measurement of maximum size of through channels of porous material and improvement of reliable tests by installation of the membrane divide the cell into two cavities. The cell with the membrane is filled with degassed distilled water and cooled to the temperature below 0°C at atmospheric pressure. Ice inoculant is added to one of the cell cavities, and after the full water freezing time elapses, temperature of the cell is started to be decreased till water crystallisation starts in the second cell cavity. Maximum size of membrane pores is found as per crystallisation beginning temperature and relationship between temperature decrease of phase equilibrium of water and ice and pore radius.

EFFECT: development of an easy non-destructive measuring method of maximum size of through-type channels of porous material; improving reliability of tests and enlarging the scope of the measured range of through-type channels into the scope of smaller pores.

1 dwg