Express method for detecting defects in polysulfone hollow fiber membranes with different porous structures

Abstract

   A new method of electroprometry has been proposed that allows continuous investigation of extended sections of a hollow fiber membrane. Samples of polysulfone hollow fiber membranes with different porous structures were obtained: finger-shaped and spongy. These membranes were examined on a laboratory electroprometric apparatus with continuous scanning along the length of the hollow fiber membrane sample at a high voltage of 15 kV. Defects were detected in these hollow fiber membranes by the proposed method of electroporometry, the nature of which was then investigated using scanning electron microscopy. A correlation was found between the size of the detected defect and the magnitude of the corona discharge current signal: the larger the defect, the greater the absolute value of the current. It is shown that the proposed method can be effectively used as an express method to study the homogeneity of the porous structure of hollow fiber membranes in extended areas with geometrical localization of possible defects.