Effects of coagulation bath temperature and polyvinylpyrrolidone content on flat sheet asymmetric polyethersulfone membranes

Abstract

In this study, effects of coagulation bath temperature (CBT) and polyvinylpyrrolidone (PVP K15) concentration as a pore former hydrophilic additive on morphology and performance of asymmetric polyethersulfone (PES) membranes were investigated. The membranes were prepared from a PES/ethanol/NMP system via phase inversion induced by immersion precipitation in a water coagulation bath. The morphology of prepared membranes was studied by scanning electron microscopy (SEM), contact angle measurements, and mechanical property measurements. Permeation performance of the prepared membranes was studied by separation experiments using pure water and bovine serum albumin (BSA) solution as feed. The obtained results indicate that addition of PVP in the casting solution enhances pure water permeation flux and BSA solution permeation flux while reducing protein rejection. Increasing CBT results in macrovoid formation in the membrane structure and increases the membrane permeability and decreases the protein rejection. POLYM. ENG. SCI., 50:885-893, 2010. FIG. 3. Cross-sectional SEM images of the PES membranes prepared with 3 wt% of PVP at different CBTs (5003 magnification): (a) 08C; (b) 258C; (c) 508C. FIG. 4. Magnified cross-sectional SEM images of the skin regions of the PES membranes prepared with 3 wt% of PVP at different CBTs (30003 magnification): (a) 08C; (b) 258C; (c) 508C. FIG. 5. SEM images from (a) top surface (50003 magnification) and (b) bottom surface (5003 magnification) of the PES membranes prepared using 3 wt% of PVP at 258C.

Preparation and characterization of poly (ethersulfone) nanofiltration membranes for amoxicillin removal from contaminated water

“…The changes imposed on membrane structure and properties after addition of Brij ® S100 and variation of PES concentrations are major reasons for PWF changes. At first, it should be noted that PWF highly depends on membrane porosity and particularly the thickness and porosity of top layer [24,31]. Above results of PWF are in agreement with trend observed in SEM images.…”

Improving fluxes of polyimide membranes containing gold nanoparticles by photothermal heating

“…Such amounts of PVP are known to alter the phase inversion process and have a notable influence on the membrane morphology, e.g. as a macrovoid suppressor (high MW) and a pore former (low MW) [30][31][32]. Specifically, for polyimide membranes, Yoo et al showed that PVP (40 kDa) influenced the thermodynamical behavior of the casting solution and the rate of solvent exchange during phase inversion and that PVP suppressed …”

Preparation and Performance Evaluation of Polyethersulfone Hollow Fiber Membranes for Ultrafiltration Processes

“…Saljoughi and co-workers [2] studied the effect of coagulation bath temperature on polymeric membranes. They discovered that increasing coagulation bath temperature increases permeability and decreases rejection.…”

“…The phase inversion method can be accomplished by a wide variety of techniques such as non-solvent induced phase separation, vapor induced phase separation, thermally induced phase separation and evaporation induced phase separation [1,2]. The non-solvent induced phase separation process is without a doubt the most widely used technique for preparation of polymeric hollow fiber membranes.…”

“…A wide range of parameters have been investigated regarding the membrane preparation mechanism and subsequently the hollow fiber membrane morphology and permeability such as concentration of polymer in the dope solution [6,7], type of solvent/non-solvent pair [3,8], cast film thickness [9], air-gap distance [3], choosing nonsolvent-solvent pairs with low mutual affinity [10], take-up speed [3], presence of certain additives [11], addition of solvent to the coagulation bath [12], coagulation bath temperature [2,3,13], presence of some other solvents [14], and addition of non-solvent to the polymer solution [15,16]. According to these literatures, it can be found that the all factors have effects on the instantaneous/delayed demixing process that takes place in the coagulation bath during the membrane preparation process.…”