Ultrafiltration membrane bubble point determinator and ultrafiltration membrane average pore size determination method

Abstract

The invention discloses an ultrafiltration membrane bubble point determinator and an ultrafiltration membrane average pore size determination method. The ultrafiltration membrane bubble point determinator comprises an average pore size bubble point pressure determination module used for detecting the air flow of ventilation micropores in an ultrafiltration membrane, and the current air pressure in an air chamber of the ultrafiltration membrane bubble point determinator is judged to be an average pore size bubble point pressure when the air flow reaches a criterion, wherein the criterion is asfollows: the air flow is 8-10ml / min. By applying the determinator and the method provided by the invention, the average pore sizes of the ultrafiltration membranes with larger pore sizes can be rapidly and accurately determined.

Description

technical field [0001] The invention relates to the measurement of structure-related parameters of an ultrafiltration membrane, in particular to an ultrafiltration membrane bubble point tester and a method for measuring the ultrafiltration membrane average pore diameter realized by the ultrafiltration membrane bubble point tester. Background technique [0002] Morphological characterization of porous membranes includes structure-related parameters as well as permeation-related parameters. Structural parameters mainly include: pore size (maximum pore size and average pore size), pore size distribution, skin thickness, and surface porosity; and permeability parameters refer to the actual separation parameters of a specific solute by a porous membrane determined by the solute rejection rate measurement. [0003] The microfiltration membrane is a porous membrane with a large pore size, while the ultrafiltration membrane is a porous membrane with a small pore size. Determining t...

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Problems solved by technology

However, since the standard particles used by various manufacturers are different, there are differences in solution concentration and working pressure, and there are also different regulations when determining the percentage of cut-off molecular weight, so this method is used to characterize The separation performance of the ultrafiltration membrane is only of reference value

[0010] However, for ultrafiltration membranes with relatively large pore diameters (the pore diameter is in the range of 0.01 to 0.1 microns), it is difficult to determine the cut molecular weight because it is difficult to select suitable ultra-large molecular weight standard particles.

[0011] To sum up, in various types of ultrafiltration membranes, on the one hand, for ultrafiltration membranes with relatively small pore diameters, the measurement results of the standard particle method are only of reference value; for ultrafiltration membranes with relatively large pore diameters, then It is difficult to use the standard particle method to measure; on the other hand, if the bubble point method is used to measure the average pore size of the ultrafiltration membrane, although the operation is relatively simple and convenient, there are two technical difficulties mentioned above

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