Polysulfone–polyurethane (PSf-PUR) blend partly degradable hollow fiber membranes: preparation, characterization, and computer image analysis

摘要

In this study, the preparation of polysulfone (PSf)-polyurethane (PUR) partly degradable hollow fiber membranes is presented. The membrane forming solution was prepared by mixing two solutions: PSf in N-methyl-2-pyrrolidone (NMP) and PUR in NMP. The PSf-PUR membranes were received by dry/wet-spinning phase-inversion technique. The membranes were hydrolyzed with sodium-hydroxide (NaOH) solution using the flowing method. The membranes were characterized by hydraulic permeability coefficient (UFC), retention coefficients, scanning electron microscopy (SEM) and mass measurement before and after hydrolysis. The changes in membranes morphology and properties due to hydrolysis were studied. Hydrolysis caused the partial removal of the PUR from the membrane structure resulting in the morphology change and the permeability's increase. The computer-aided image processing method was also used to investigate the morphology before and after the-hydrolysis process. This method checked out the changes of membranes' morphology by the dissimilarity coefficient (values not equal 0). The SEM images showed differences in structure of pores before and after the hydrolysis process. The structures and morphology of the membranes after hydrolysis were more porous. The hydraulic permeability coefficients were higher after the hydrolysis process. The retention coefficients were different before and after the hydrolysis process.