Poly(4-methyl-1-pentene) Membrane for CO2 Separation: Performance Comparison of Dense and Anisotropic Membrane

Impact of dope extrusion rate and multilayer polydimethylsiloxane coating on asymmetric polyethersulfone hollow fiber membrane for CO2/N2 and CO2/CH4 separation

“…Despite of the presence of the pinholes, the closely packed polymer at the dense skin layer still offers sufficient resistance to the penetrating gas as the pinholes does not penetrate all the way through to the porous substructure support as observed from the cross‐sectional image in Figure 4. As such, the skin layer still offers some degree of resistance to the penetrating gas as there is still small degree of separation occurring at the dense skin layer although the separation is not significant due to the incomplete polymer coalescence that often occurs with asymmetric membrane fabrication 42,43 . Figure 8a,b shows the gas separation performance of M1 and M2 PES HF coated with a single PDMS layer respectively.…”

“…The CO 2 /N 2 and CO 2 /CH 4 selectivity does not improve regardless of the number of sequential coating for both M1 and M2 membrane with increasing upstream pressure. Even though dense skin layer is formed with the critical concentration of PES used for asymmetric HF fabrication, the fast liquid–liquid demixing may have developed a lot of pinholes and incomplete polymer coalescence region that may impede the gas selectivity 6,43 . Apparently, Chung et al 19,20 and Ismail et al 47 discovered that the shear rate also plays an important role in forming dense selective skill layer with oriented molecular orientation.…”

“…As such, the skin layer still offers some degree of resistance to the penetrating gas as there is still small degree of separation occurring at the dense skin layer although the separation is not significant due to the incomplete polymer coalescence that often occurs with asymmetric membrane fabrication. 42,43 PDMS coating is applied by a simple dip-coating procedure. PDMS is a highly permeable polymer and typically used as a coating layer to seal membrane's surface defect.…”

“…Even though dense skin layer is formed with the critical concentration of PES used for asymmetric HF fabrication, the fast liquid-liquid demixing may have developed a lot of pinholes and incomplete polymer coalescence region that may impede the gas selectivity. 6,43 Apparently, Chung et al 19,20 and Ismail et al 47 discovered that the shear rate also plays an important role in forming dense selective skill layer with oriented molecular orientation. HF membrane fabricated with high shear rate appeared to exhibit higher gas selectivity after it was coated with PDMS as compared to HF membrane fabricated with lower shear rate.…”

Prediction of CO2 Permeance across ZIF-L@PDMS/PES Composite Membrane

“…Polymeric membranes are a simple yet effective method for gas separation. As the research progress and its formulations evolve, the polymeric membrane can be grouped according to its configuration: symmetric or asymmetric [ 1 ]. Specifically, in this study, an asymmetric membrane consisting of two different materials was examined.…”