Microporous polyvinylidene fluoride(PVDF)hollow fibre membranes were spun using the dry-wet phaseinversion method.By means of dip-coating technique,a uniform coating with thickness of around 5-12 μm of polyvinyldimet...Microporous polyvinylidene fluoride(PVDF)hollow fibre membranes were spun using the dry-wet phaseinversion method.By means of dip-coating technique,a uniform coating with thickness of around 5-12 μm of polyvinyldimethylsiloxane(PVDMS)was formed on the surface of porous PVDF hollow fibers.The structural parameters of PVDFsubstrate membrane were estimated by gas permeation test.Using N_2/O_2 as the medium,the separation properties ofPVDMS-PVDF composite hollow fiber membranes were also evaluated experimentally.The experimental data of bothpermeability and selectivity are in good agreement with the theoretical results predicted by the presented pore-distributionmodel.In order to obtain the compact composite membrane free of defects by the dip-coating technique,the thickness ofPVDMS skin must be higher than 5 μm.展开更多
Composite polyurethane(PU)-SiO_2 hollow fiber membranes were successfully prepared via optimizing thetechnique of dry-jet wet spinning,and their pressure-responsibilities were confirmed by the relationships of pure wa...Composite polyurethane(PU)-SiO_2 hollow fiber membranes were successfully prepared via optimizing thetechnique of dry-jet wet spinning,and their pressure-responsibilities were confirmed by the relationships of pure water flux-transmembrane pressure(PWF-TP)for the first time.The origin for this phenomenon was analyzed on the basis of membranestructure and material characteristics.The effects of SiO_2 content on the structure and properties of membrane wereinvestigated.The experimental results indicated that SiO_2 in membrane created a great many interfacial micro-voids andplayed an important role in pressure-responsibility,PWF and rejection of membrane:with the increase of SiO_2 content,theability of membrane recovery weakened,PWF increased,and rejection decreased slightly.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.20076025).
文摘Microporous polyvinylidene fluoride(PVDF)hollow fibre membranes were spun using the dry-wet phaseinversion method.By means of dip-coating technique,a uniform coating with thickness of around 5-12 μm of polyvinyldimethylsiloxane(PVDMS)was formed on the surface of porous PVDF hollow fibers.The structural parameters of PVDFsubstrate membrane were estimated by gas permeation test.Using N_2/O_2 as the medium,the separation properties ofPVDMS-PVDF composite hollow fiber membranes were also evaluated experimentally.The experimental data of bothpermeability and selectivity are in good agreement with the theoretical results predicted by the presented pore-distributionmodel.In order to obtain the compact composite membrane free of defects by the dip-coating technique,the thickness ofPVDMS skin must be higher than 5 μm.
文摘Composite polyurethane(PU)-SiO_2 hollow fiber membranes were successfully prepared via optimizing thetechnique of dry-jet wet spinning,and their pressure-responsibilities were confirmed by the relationships of pure water flux-transmembrane pressure(PWF-TP)for the first time.The origin for this phenomenon was analyzed on the basis of membranestructure and material characteristics.The effects of SiO_2 content on the structure and properties of membrane wereinvestigated.The experimental results indicated that SiO_2 in membrane created a great many interfacial micro-voids andplayed an important role in pressure-responsibility,PWF and rejection of membrane:with the increase of SiO_2 content,theability of membrane recovery weakened,PWF increased,and rejection decreased slightly.
