Water vapor permeation and morphology of polysulfone membranes prepared by phase inversion

Abstract

The aim of this work was to study the effect of different variables in the morphology and water vapor permeation of asymmetric membranes. Different from other works on vapor induced phase inversion this work focus on the formation of a dense skin capable of separating small molecules like gases and on the transport properties of water vapor instead of liquid water. It also correlates the morphologies with the permeability. The results show that higher polymer concentrations lead to denser skin and lower permeability. Water vapor transmission rates varied from 30 to 48 g/m 2 .h depending on membrane morphology. They also show that for membranes with the same type of skin layer the permeability depends on the sub-layer. Finally, the results suggest that different mechanisms were responsible for the formation of the membranes.

Fabrication of mixed matrix polyphenylsulfone‐polysulfone blend membranes incorporated with Nickel/Hydrazine@silica core‐shell nanoparticles using VIPS‐NIPS method for efficient dye rejection

“…Figure 5 exhibits the low‐ and high‐magnification cross‐sectional FESEM images of the pristine and mixed matrix membranes. It is obvious that a symmetric cellular structure has been formed in all the membranes structure, indicating that the formation of the membranes have conducted through delayed demixing 39 . Indeed, the use of the VIPS approach coupled with the NIPS method has resulted in the formation of a sponge‐like structure 60 .…”

“…It is obvious that a symmetric cellular structure has been formed in all the membranes structure, indicating that the formation of the membranes have conducted through delayed demixing. 39 Indeed, the use of the VIPS approach coupled with the NIPS method has resulted in the formation of a sponge-like structure. 60 Additionally, the presence of fabricated nanoparticles increases the polymer solution density and limits the solvent-nonsolvent exchange, by which delayed demixing can be promoted, by which a denser skin layer, smaller pores, and therefore, more rejection performance can be achieved.…”

“…[36][37][38] It has been confirmed that the VIPS approach can be also coupled with the NIPS one, causing the formation of a porous membrane with superior properties and no pin-holes on the dense layer. 35,39,40 By coupling these two methods, it will be feasible to utilize both methods merits while lessening their demerits. 28,41,42 In spite of all the above-mentioned advantages of poly(aryl sulfone) membranes, it is still vital to enhance these membranes properties.…”

“…In the VIPS approach, the polymeric solution is first cast on a glass, followed by exposing with water vapor, leading to the diffusion of the non‐solvent vapor into the bulk due to the great affinity between solvent and non‐solvent 36–38 . It has been confirmed that the VIPS approach can be also coupled with the NIPS one, causing the formation of a porous membrane with superior properties and no pin‐holes on the dense layer 35,39,40 . By coupling these two methods, it will be feasible to utilize both methods merits while lessening their demerits 28,41,42 …”

CVD-Deposited Oxygen-Selective Fluorinated Siloxane Copolymers as Gas Diffusion Layers

“…Since iCVD-fabricated GDLs were very thin (∼300–400 nm), Psf membranes were used to mechanically support homo and copolymer iCVD films during WVP measurements. The as-prepared Psf support membranes have a water permeability of 3.38 × 10 –9 mol m m –2 Pa –1 s –1 and a WVTR approximately 9.84 × 10 2 g m –2 day –1 , making Psf a very suitable support material to measure the oxygen and water permeabilities of iCVD-fabricated GDLs. , WVP and WVTR values of poly­(V4D4), poly­(PFHEA), and poly­(PFEMA) homopolymers and their copolymers are given in Table .…”