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Both hydrophobic and hydrophilic pollutions have damage on our environment, and it is necessary to remove them. However, the treatments for different water pollutions can be specific due to the hydrophobicity of various molecules. Therefore, it is important to separate pollutants with different hydrophobicity. In this work, we developed a diffusion separation method based on hydrophobicity selectivity polymer membranes, whose selectivity between hydrophilic and hydrophobic pollutants can be up to more than 100. By doping pH‐responsive monomer into hydrophobic polymer membrane, the permeability of membrane can be tuned by surrounding pH, and the selectivity is not decreasing. With the results of characteristics on contact angle, scanning electron microscope, and mechanical properties, we prove the stimuli‐responsive polymer membrane at different states have similar properties with the nonresponsive amorphous polymer membranes with high separation selectivity. [ABSTRACT FROM AUTHOR]

To overcome the two main obstacles of large‐scale application of superspreading material, self assembly is used to prepare superspreading polymer membrane (SPPM) in this work. An amphiphilic SPPM is prepared by capillary force‐driven self assembly using PP melt‐blown nonwovens and polyvinyl alcohol (PVA). The prepared SPPM has low preparation cost and stable performance since self assembly needs low energy consumption, and the production is thermodynamically stable. By using cryo‐electron microscopy, transmission electron microscopy, X‐ray photoelectron spectrum and scanning electron microscope with energy dispersive X‐ray spectroscopy. It is proved that PVA is successfully assembled on the fiber surface of PP melt‐blown nonwovens. The prepared SPPM has excellent spreading performance, the “spreading times” of both water and oil are less than 0.5 s. They showed much superior performance compared to traditional materials when applied in oil‐water separation, seawater desalination, and ion separation. This work will definitely promote the development of self assembly, superspreading materials, and related sciences. [ABSTRACT FROM AUTHOR]

Membrane‐based CO2 separation is vital for various applications such as biogas upgradation. Polymer membranes are employed for CO2 separation in the industry. Polymer membranes have a trade‐off between selectivity and permeability. Blending polymers is an emerging approach for altering the gas transport in the membranes. This work investigates the fabrication and characterization of blended biodegradable cellulose acetate (CA) with polyimide (PI). Thermal stability was characterized using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and functional groups were analyzed using Fourier transform infrared spectroscopy (FTIR). The morphology of membranes is analyzed using field‐emission scanning electron microscope (FESEM). The blend membranes were tested for separation of CO2 from model biogas (CO2/CH4) at room temperature and a low feed pressure (∼1.5 bar). The CA:PI blend membrane composed of 93% CA and 7% PI showed CO2 permeability of 19.71 Barrer, approximately 206% greater than pure CA, and CO2/CH4 selectivity was 9.42. Experimental results are compared with literature on CA‐based membranes. Highlights: Blend membrane of cellulose acetate (CA) and polyimide (PI)CO2/CH4 gas permeation testing of membranes using a model biogas mixtureBlend membranes exhibit 206% higher CO2 permeability than pure CA membranesBlend membranes demonstrated enhanced CO2/CH4 selectivity of 9.42. [ABSTRACT FROM AUTHOR]

This study is the first attempt to fabricate a heat‐resistant hollow fiber ultrafiltration membrane using poly(m‐phenylene isophthalamide) (PMIA) polymer material, which has rarely been used as conventional polymeric membrane materials. Multi‐walled carbon nanotubes (MWCNTs) are incorporated as reinforcing agents. The PMIA polymer synthesized for this study exhibited an inherent viscosity of 1.6 dL/g, confirming its suitability for membrane fabrication, and successful synthesis was verified through Fourier‐transform infrared analysis. To enhance the dispersibility of MWCNTs during dope solution preparation and their interaction with the PMIA matrix, MWCNTs were acid‐treated and surface characteristics of the acid‐treated MWCNTs were confirmed through x‐ray photoelectron spectroscopy analysis. Scanning electron microscope analysis revealed that the introduction of MWCNTs resulted in thicker PMIA hollow fiber ultrafiltration membranes with symmetrical finger‐like and sponge‐like pore structures. Interestingly, unlike the typical polymer composite systems containing MWCNTs, which often show a dependence on MWCNT content, the mechanical properties of the PMIA/MWCNT membranes in this study seem to exhibit high variability and are not contingent on the MWCNT content. Additionally, filtration performance studies demonstrated that the introduction of MWCNTs substantially increased water permeability, particularly at 1.0 wt% MWCNT content, resulting in a remarkable 130% enhancement compared to pristine PMIA membrane. Simultaneously, even with a small quantity of MWCNTs, the rejection performance of the PMIA/MWCNT membrane witnessed significant improvement due to the reduction in average pore size, effectively overcoming the commonly observed trade‐off phenomenon. In summary, this study clearly showed the effects and changes on the structure and properties of a heat‐resistant PMIA‐based hollow fiber ultrafiltration membranes due to the introduction of MWCNTs. Highlights: Heat‐resistant poly(m‐phenylene isophthalamide)‐based hollow fiber ultrafiltration membranesIntroduction of multi‐walled carbon nanotubes (MWCNTs) into PMIA membrane as a reinforcing agentUnique structural changes of PMIA membrane originated from the MWCNTsEnhanced tensile strength of PMIA/MWCNT membranesSimultaneous improvement of filtration performance due to MWCNTs [ABSTRACT FROM AUTHOR]

Since it may rehabilitate phenol without creating secondary waste, the liquid membrane Polymer Inclusion Membrane (PIM) technique has recently been the focus of several investigations. This study employed the PIM approach to phenol transport utilizing the carrier Poly-Bisphenol A Diglycidyl Ether (Poly-BADGE) at 1:1 and 3:1 polyeugenol to BADGE ratios. Numerous phenol transport parameters were investigated, including the impact of pH on the phenol source phase, the concentration on the sodium hydroxide receiving phase, membrane thickness, and the time of the phenol transport process using the PIM technology. Dissolving the carrier, polyvinyl chloride, and dibenzyl ether in tetrahydrofuran solvent produced an elastic and porous PIM. UV-Vis Spectrophotometer was then used, along with the addition of a 4-amino antipyrine reagent, to ascertain the phenol content following transport. The wavelength at which absorbance was measured was 460 nm. The findings from the research suggest that, given optimal conditions such as a source phase 5.5 pH, a receiving phase concentration of 0.10 M sodium hydroxide, a membrane thickness of T54 type PIM membrane, and a transport time of 24 hours phenol can be effectively transported using PIM with Poly-BADGE carriers at ratios of 1:1 and 3:1, achieving transport efficiencies of 57.31% and 85.30%, respectively. The BADGE was examined using Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM) before and after transport. [ABSTRACT FROM AUTHOR]

Polymer inclusion membrane (PIM) has become a potential alternative in efficient Li + separation from brines typically with Mg2+ and Li+, due to its exceptional stability and selectivity. However, the practical application of PIMs is still greatly restricted by its slow mass transfer and related unclear transport mechanism. Here, we fabricated an efficient PIM with tributyl phosphate (TBP) along with sodium tetraphenylborate (NaBPh 4) as carriers and cellulose triacetate (CTA) as a polymer skeleton for highly selective and permeable Li + separation from high Mg2+/Li+ aqueous solutions, offering an initial flux of 3–20 times higher than other PIMs. With increasing TBP content in the PIM, a nonmonotonical trend (sharp increase-leveling off-slow decrease) of its initial flux was observed. The improvement of the solubility (compatibility) of NaBPh 4 in CTA matrix by introducing TBP was demonstrated by scanning electron microscope (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) images, which was highly consistent with binding energy simulation. X-ray diffraction (XRD) and positron annihilation lifetime spectroscopy (PALS) results verify that moderate TBP content in the PIM could enlarge the distance of polymer chains and enhance the initial flux of PIMs, while excessive TBP can occupy the free volume sites, leading to an adverse effect on the permeability. Our study provides valuable information on the compatibility effect on the mass transfer through the polymer matrix including PIMs, which exhibits prospect in a wide range of applications of metal separation. [Display omitted] • A NaBPh 4 -TBP-CTA PIM is proposed to separate Li+ from high Mg2+/Li+ solutions. • The initial flux of the PIM could be 20 times higher than that of previous PIMs. • A sharp increase-leveling off-slow decrease trend of the initial flux is observed. • Moderate TBP enlarges the distance of polymer chains and enhances the initial flux. • Excessive TBP can occupy the free volume sites to adversely affect the permeability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defect-free mixed matrix membranes (MMMs) with a flux of 1519 g·m−2·h−1 and a separation factor of 452 were developed for separating 90 wt% aqueous ethanol solutions. • ZIF-8 Surface segregation substrates prepared by vapour-assisted non-solvent induced phase separation (NIPS). • The high performance of MMMs, with an easily scalable substrate, showed great potential for industrialization. Mixed matrix membranes (MMMs), which incorporate porous particles into polymer matrix, were a promising approach to overcome the inherent trade-off effect of polymeric membranes. Controllable and easily scalable membrane fabrication strategies remained a challenge for the development of defect-free pervaporation MMMs. In this work, to avoid defects formed by particle exposure in MMMs, forced surface segregation of ZIF-8 on a substrate was achieved by vapor-assisted non-solvent induced phase separation (NIPS) process. Subsequently, ZIF-8 'islands' on the substrate surface were sealed with PVA solution and defect-free dense MMMs were successfully prepared. The surface segregation of ZIF-8 was proved by scanning electron microscope (SEM), X-Ray diffraction (XRD) and fourier transform infrared (FTIR). The prepared MMMs showed an increase in flux of 162% and an increase in separation factor of 299% compared to the pristine membranes. It was expected that this strategy of inducing particles to undergo forced surface segregation could be extended to the preparation of other membranes. [ABSTRACT FROM AUTHOR]