The effects of substrate characteristics and pre-wetting agents on PAN–PDMS composite hollow fiber membranes for CO2/N2 and O2/N2 separation

Composite hollow fiber membranes with different poly(dimethylsiloxane) intrusions into substrate for phenol removal via extractive membrane bioreactor

“…PDMS was reported to have high gas permeability and good selectivity: Markel et al reported that the intrinsic O 2 /N 2 selectivity for PDMS was 2, while Li et al observed values between 1.9 and 2.4 for their defect-free PDMS composite hollow fiber membranes [14,20]. The higher O 2 permeance across PDMS compared with N 2 is mainly due to a higher solubility of O 2 in PDMS [14].…”

“…While PDMS intrusion may help in enhancing the adhesion between the coating layer and the substrate, it also increases the membrane resistance. It has been reported that the mass transfer resistance of a composite membrane increases linearly with the PDMS intrusion depth [20]. Therefore, PDMS intrusion is normally undesirable and hence various techniques, such as pre-wetting of substrate pores by liquid and use of highviscosity coating solution, have been employed to minimize it during coating [20,21].…”

“…It has been reported that the mass transfer resistance of a composite membrane increases linearly with the PDMS intrusion depth [20]. Therefore, PDMS intrusion is normally undesirable and hence various techniques, such as pre-wetting of substrate pores by liquid and use of highviscosity coating solution, have been employed to minimize it during coating [20,21]. In this work, PDMS was coated on Polyetherimide (PEI) hollow fiber substrate to prepare composite membranes, while membranes with different levels of PDMS intrusion were prepared for comparison.…”

Preparation and characterization of a polyethersulfone/polyaniline nanocomposite membrane for ultrafiltration and as a substrate for a gas separation membrane

“…While recently more and more researchers are realizing the importance of porous membrane supports on the performance of composite membrane and attempt to figure out the suitable properties of substrates for fabricating composite membrane. [19][20][21][22][23][24][25][26] In the published studies, the surface properties of the substrates were mainly altered by varying the polymer concentration 21 and blending polyvinylpyrrolidone (PVP) or poly (ethylene glycol) (PEG) 23 in the casting solution. It was reported that the porous support membrane could exert an effect on the selective layer structure besides providing the mechanical support for fabricating composite membrane.…”

Layer-by-layer (LbL) polyelectrolyte membrane with Nexar™ polymer as a polyanion for pervaporation dehydration of ethanol

“…The outer surface of the hollow fiber is dense while its inner surface and cross-section are very porous. This morphology is achieved by employing a strong external coagulant (water) and a mild internal coagulant (95/5 w/w NMP/water) during the hollow fiber spinning[34,35]. The dense outer surface is desirable for the deposition of polyelectrolyte layers while the porous inner surface and cross-section may provide minimum transport resistance.…”