Composite Polyamide Membranes Research Articles

Urea interfacial polymerization-based ultra-permeable polyamide composite membrane for efficient piggery wastewater purification

Urea interfacial polymerization-based ultra-permeable polyamide composite membrane for efficient piggery wastewater purification

Ceramic supported polyamide composite nanofiltration membrane with a glutaraldehyde cross-linked chitosan interlayer

Interfacial polymerization has been applied to prepare polyamide (PA) membrane on ceramic substrate. However, the low compatibility of the organic PA layer with the ceramic substrate and the intrusion of the PA layer into the ceramic substrate impedes the performance of the obtained membrane. Herein, building on previous work, a thinner interlayer (a glutaraldehyde (GA) cross-linked chitosan (CCM) interlayer) is constructed on a ceramic ultrafiltration substrate (∼5 nm) for the subsequently interfacial polymerization to improve the performance of the obtained membrane. FTIR, XPS and FESEM analyses confirm the successful construction of a smooth interlayer with a thickness of ∼250 nm and the subsequently formation of a homogeneous, rough polyamide (PA) layer with a thickness of ∼15 nm. The obtained membrane has a hydrophilic surface and a negative charged property. The molecular weight cut-off (MWCO) of the obtained membrane is 404 Da. A thinner interlayer of the composite membrane leads to a water flux of 149.46 L m−2 h−1 (0.4 MPa) with rejections of Na2SO4 84.71 %, MgSO4 81.07 %, MgCl2 63.39 %, CaCl2 58.7 %, and NaCl 51.87 %. The interlayer regulates the macroporous structure of the ceramic substrate to prevent the intrusion of the PA layer. Furthermore, the interlayer enhances the connection between the PA layer and the ceramic substrate, which enhances the stability of the PA/CCM membrane (stable performance during 20 h continuous filtration). Overall, this work provides a simple way (construct a glutaraldehyde (GA) cross-linked chitosan interlayer) to prepare composite nanofiltration membranes on ceramic substrate, which has potential applications in dyes desalination.

Nanofoamed Polyamide Membranes: Mechanisms, Developments, and Environmental Implications.

Thin film composite (TFC) polyamide membranes have been widely applied for environmental applications, such as desalination and water reuse. The separation performance of TFC polyamide membranes strongly depends on their nanovoid-containing roughness morphology. These nanovoids not only influence the effective filtration area of the polyamide film but also regulate the water transport pathways through the film. Although there have been ongoing debates on the formation mechanisms of nanovoids, a nanofoaming theory─stipulating the shaping of polyamide roughness morphology by nanobubbles of degassed CO2 and the vapor of volatile solvents─has gained much attention in recent years. In this review, we provide a comprehensive summary of the nanofoaming mechanism, including related fundamental principles and strategies to tailor nanovoid formation for improved membrane separation performance. The effects of nanovoids on the fouling behaviors of TFC membranes are also discussed. In addition, numerical models on the role of nanovoids in regulating the water transport pathways toward improved water permeance and antifouling ability are highlighted. The comprehensive summary on the nanofoaming mechanism in this review provides insightful guidelines for the future design and optimization of TFC polyamide membranes toward various environmental applications.

Carbon nanotube intermediate layer intercalation and its influence on surface charge of thin film composite membrane

The surface charge of a separation membrane is a critical factor affecting its performance in ion separation and fouling resistance. Thin-film composite (TFC) polyamide (PA) membrane, commonly used in water treatment, often suffer from excessive surface negative charges, which significantly limits their application and fouling resistance. To address this issue, this work introduces a carbon nanotubes (CNT) intermediate layer to adjust the surface charge of TFC PA membranes, aiming to achieve a PA layer with neutral properties. Novel grazing-incidence wide-angle x-ray scattering (GIWAXS) measurements were employed to elucidate the effect of CNT on the molecular chain stacking of PA. The CNT intermediate layer was found to influence the PA cross-linking, which is related to surface negative charge, by controlling the storage and release of the m-phenylenediamine monomer during interfacial polymerization. The neutral CNT-TFC membrane demonstrated improved NH4+ retention and increased resistance to fouling by protein, surfactant, and E. coli. However, other surface properties, such as roughness and hydrophilicity, could counteract the antifouling benefits of a neutral surface. This work provides insights into additional advantages of CNT intermediate layer intercalation in TFC PA membranes, such as enhanced cross-linking and surface charge control.

Biomimetic polyamide composite membrane with excellent resistance to humidity fluctuations for high-efficiency CO2 separation

The development of polyamide membranes with superior and stable permselectivity is vital in CO2 capture. However, the current polyamide membranes face a challenge of permselectivity fluctuating greatly with feed gas humidity, critically restricting their industrial applications. Inspired by the architectural structure of rooted grasses in soil, herein, a biomimetic polyamide composite membrane comprised of an ultrathin polyamide upper layer, a calcium alginate (CA) hydrogel lower layer, as well as an interwoven transition layer was purposely developed. The highly hydrophilic hydrogel layer could flexibly absorb and release water according to the humidity fluctuations of feed gas. More importantly, the rooted interwoven structure allowed rapid water exchange between hydrogel and polyamide, thereby efficiently maintaining the appropriate water content in ultrathin polyamide layer (∼8 nm), leading to a relatively stable CO2 separation performance. The composite membrane exhibited a slightly reduction of 7 % in CO2/N2 selectivity when relative humidity changing from 98 % to 70 %, significantly lower than that of pristine polyamide membrane (81 %). Moreover, the CO2 permeance of the membrane maintained at ∼ 80 GPU, demonstrating excellent anti-fluctuation capability with humidity. This work puts forward a biomimetic strategy for constructing polyamide membrane to address the tackle of high dependence on humidity in CO2 capture.

Screening of the biphenyl polyamides nanofilms appropriate for molecular separation in organic solution feed

Developing polymeric separation membranes that combine excellent solvent stability, high permeability, and customizable molecular weight interception remains a challenge. Herein, thin-film composite (TFC) polyamide (PA) membranes with poly(ether ether ketone) (PEEK) support and biphenyl-centered polyamides active layer were fabricated through interfacial polymerization technique for the first time. Enhanced solvent stability was exhibited by the fabricated membranes due to the intrinsic resistance to organic solvents possessed by PEEK and biphenyl polyamides. The separation performance of the obtained membranes was systematically studied by relating to the properties of PA nanofilms in terms of nano-mechanical strength, morphologies, and microporosity. The organic solvent nanofiltration (OSN) performance of the resultant membranes in terms of permeability and molecular weight cut-off (MWCO) could be regulated. The optimized membrane exhibited a pure solvent permeability as high as 21.6 L m−2 h−1 bar−1 for acetonitrile and 14.0 L m−2 h−1 bar−1 for methanol. It also showed excellent long-term durability with almost unchanged permeability as well as solute retention remained above 97.8 % after a cumulative OSN operation of N, N-Dimethylformamide (DMF) based feed for 240 h. In particular, OSN membrane with targeted MWCOs covering the range of 170–370 g·mol−1 could be fabricated by selecting appropriate biphenyl acyl chlorides as building blocks. This approach offers a scalable and versatile platform for the development of solvent-stable, highly permeable, and customizable MWCO membranes for process-oriented OSN.

Construction of sub-10nm ultra-thin polyamide layer using porous GOQDs-AGQDs interlayer

The application of high-performance polyamide nanofiltration membranes with controllable structures shows promising prospects in fields such as seawater desalination and wastewater treatment. In this study, a high-performance polyamide composite nanofiltration membrane with sub-10nm ultra-thin separation layer was designed and fabricated using a hydrophilic porous GOQDs-AGQDs (graphene oxide quantum dots-amino graphene quantum dots) interlayer to reconstruct the substrate architecture. The GOQDs-AGQDs interlayer not only improved the uniformity and smoothness of the microporous substrate, but also could form hydrogen bond with amine monomers to effectively inhibit its diffusion, thereby effectively slowing down the interfacial polymerization process and facilitating the formation of an ultra-thin, smooth and dense polyamide (PA) layer. The results demonstrate that the optimized PA/GOQDs-AGQDs/PES membrane achieved a PA separation layer thickness as low as 9.4 nm, with a permeation flux of 27.2 L·m−2 ·h−1·bar−1, nearly three times that of the original PA/PES membrane. Simultaneously, it enhanced the Na2SO4 rejection rate to 97.1 %, achieving synchronous improvements in permeability and selectivity. Additionally, the PA/GOQDs-AGQDs/PES composite membrane exhibited relatively low surface roughness and demonstrated excellent long-term stability. This work presents a novel strategy for the controllable fabrication of high-performance nanofiltration membranes.

Controllable Design of Polyamide Composite Membrane Separation Layer Structures via Metal-Organic Frameworks: A Review.

Optimizing the structure of the polyamide (PA) layer to improve the separation performance of PA thin-film composite (TFC) membranes has always been a hot topic in the field of membrane preparation. As novel crystalline materials with high porosity, multi-functional groups, and good compatibility with membrane substrate, metal-organic frameworks (MOFs) have been introduced in the past decade for the modification of the PA structure in order to break through the separation trade-off between permeability and selectivity. This review begins by summarizing the recent progress in the control of MOF-based thin-film nanocomposite (TFN) membrane structures. The review also covers different strategies used for preparing TFN membranes. Additionally, it discusses the mechanisms behind how these strategies regulate the structure and properties of PA. Finally, the design of a competent MOF material that is suitable to reach the requirements for the fabrication of TFN membranes is also discussed. The aim of this paper is to provide key insights into the precise control of TFN-PA structures based on MOFs.

High-Performance Nanofiltration Membrane with Dual Resistance to Gypsum Scaling and Biofouling for Enhanced Water Purification.

Nanofiltration (NF) technology is pivotal for ensuring a sustainable and reliable supply of clean water. To address the critical need for advanced thin-film composite (TFC) polyamide (PA) membranes with exceptional permselectivity and fouling resistance for emerging contaminant purification, we introduce a novel high-performance NF membrane. This membrane features a selective polypiperazine (PIP) layer functionalized with amino-containing quaternary ammonium compounds (QACs) through an in situ interfacial polycondensation reaction. Our investigation demonstrated that precise QAC functionalization enabled the construction of the selective PA layer with increased surface area, enhanced microporosity, stronger electronegativity, and reduced thickness compared to the control PIP membrane. As a result, the QAC NF membrane exhibited an approximately 51% increase in water permeance compared to the control PIP membrane, while achieving superior retention capabilities for divalent salts (>99%) and emerging organic contaminants (>90%). Furthermore, the incorporation of QACs into the PIP selective layer was proved to be effective in mitigating mineral scaling by allowing selective passage of scale-forming cations, while simultaneously exhibiting strong antimicrobial properties to combat biofouling. The in situ QAC incorporation strategy presented in this study provides valuable guidelines for the fit-for-purpose design of the selective PA layer, which is crucial for the development of high-performance NF membranes for efficient water purification.

Photosensitive and high temperature resistant polyamide composite nanofiltration membranes with high flux and stable retention

Currently, most commercial membranes are used at temperatures below 50 °C. For high temperature water treatment, nanofiltration membranes with good thermal stability are highly sought after. In order to construct a novel polyamide thin-film composite nanofiltration (TFC NF) membrane, Congo red (CR) as monomer was introduced to the aqueous phase and the chemical structure of the selective layer was changed. Next, a thorough investigation was conducted into the impacts of the piperazine (PIP) to CR ratio on the surface morphology, separation efficiency and chemical structure of the membranes. The TFC NF membrane prepared after parameter optimization exhibited high retention (Na2SO4, >98 %) and flux up to 30 L·m−2·h−1·bar−1 at room temperature. Moreover, the Na2SO4 retention of the TFC NF membrane decreased by less than 1 % when used at 90 °C, demonstrating excellent heat resistance. Meanwhile, the incorporation of CR allowed the structure of the TFC NF membranes to be altered under UV irradiation conditions, which provided new insights into the optical modulation of the composite membrane properties. A promising and reproducible methodology for the development of high flux TFC NF membrane with thermal stability was offered, achieving a breakthrough in water treatment technology under high-temperature conditions.

Elastic response of layer-by-layer self-assembly nanofiltration membranes to hydraulic pressure

Membrane compaction has been often observed in pressure-driven membrane processes, resulting in deformation of membrane morphology and reduction in permeation and separation performance. Current studies on the compaction of nanofiltration (NF) membranes exclusively focused on thin-film composite (TFC) polyamide membranes prepared by interfacial polymerization (IP). The compaction of layer-by-layer (LBL) self-assembled NF membranes under high pressure has not yet been discussed. In this work, we explored the response of a flat-sheet LBL (PSS/PAH)2.5 membrane to hydraulic pressure in terms of the overall separation performance. The polysulfone (PSF) substrate of LBL membranes demonstrated an irreversible compaction similar to commercial acid-resistant KH membranes prepared by IP technology, but the polyelectrolyte (PE) selective layer surprisingly showed full recovery in the pore size and separation performance in the range of 10–40 bars. At 40 bar, the pore size of LBL membranes was enlarged, resulting in decreased rejection of MgCl2. However, in a 15% phosphoric acid feed, the LBL membranes showed slight changes in the pore size, due to stronger binding of PSS and PAH at low pH. The response of the LBL layer to pressure was related to the substrate pore size, coating layers and the binding strength of the PE pairs. For commercial acid-resistant TFC KH membranes, the decrease in substrate porosity at high pressure caused a significant reduction in the permeance but minor changes in the separation layer; the separation layer of KH membrane remained intact in water but swelled in acid with slightly increased pore size but stable salt rejection. The sharp contrast of LBL and TFC NF membranes highlighted the unique “elastic” response of LBL active layer and provided a new dimension for the design and utility of LBL membranes in different applications.

V-shape Tröger's base-based organic solvent nanofiltration membranes for fast and precise molecular separation

Organic solvent nanofiltration (OSN) membranes with precise molecular-sieving performance have become increasingly important in chemical and pharmaceutical industries, desiring superior membranes with both high permeability and selectivity. Herein, the V-shape Tröger's base (TB) structure is incorporated in the polyamide network to engineer microporosity as well as the molecular-sieving performance of the thin-film composite (TFC) polyamide membrane for organic solvent nanofiltration (OSN). The TFC membrane containing the TB structure features a rigid and contorted chain structure, which affords high and stable methanol permeability in OSN applications. Furthermore, the H-bond interaction between the H of amide groups and N in TB reinforces the interchain interaction, endowing the membrane with a precise selectivity to organic solutes. The as-prepared TFC membrane demonstrated high methanol permeance of 16.6 L m−2 h−1 bar−1 and sieving performance to organic molecules with molecular weight cut-off (MWCO) down to 349 Da. Furthermore, the membrane demonstrates shape selectivity for organic solutes, exploiting the fine microporous structure. This study may provide insights into the molecular design of TFC membranes by finely tuning the molecular features for precise solute separations.

Modulating interfacial polymerization dynamics in nanostructured thin-film composite membranes: The role of polyvinylpyrrolidone and NaCl

Optimizing the performance of thin-film composite polyamide (TFC-PA) membranes is crucial for enhancing filtration efficiency across diverse applications. This study investigated the role of polyvinylpyrrolidone (PVP) in modulating the diffusion kinetics of piperazine (PIP) during the interfacial polymerization (IP) process, essential for membrane fabrication. By incorporating PVP into the aqueous phase, and combining it with selected inorganic salts such as sodium chloride (NaCl), the formation of a more controlled Turing-like nanostructure within the PA layer was achieved, significantly improving membrane permeability and structural uniformity. Employing molecular simulations alongside diverse characterization techniques, the mechanisms by which PVP and NaCl additives influence the diffusion of PIP monomers at the water-oil interface were elucidated. The optimized membranes demonstrated a substantial increase in water permeability, achieving 16.2 ± 0.9 L m−2 h−1 bar−1, and an impressive sodium sulfate (Na2SO4) rejection rate of 97.5 ± 0.6 %, outperforming untreated nanofiltration (NF) membranes. The findings provide a deeper understanding of the molecular interactions during IP and open avenues for the development of advanced filtration membranes with tailored properties.

Effect of surfactants on the permeation rate and selectivity of polyamide composite membranes for organic solvent nanofiltration

Solvent-resistant membranes are pivotal in industrial separations. This study aims to develop thin-film composite polyamide (TFC-PA) membranes with enhanced organic solvent nanofiltration (OSN) capabilities. Polyallylamine hydrochloride (PAAH) was used as the aqueous amine and isophthaloyl chloride (IPC) as the crosslinker to form the polyamide active layer by interfacial polymerization (IP) on a polyacrylonitrile (PAN) support. The impact of using anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB) to act as phase transfer agents during IP was investigated to understand their potential for facilitating the transfer of PAAH to the organic phase for reaction with IPC. The SDS and CTAB were separately dissolved into the PAAH solutions before IP to evaluate their effects on membrane properties. Extensive characterization including SEM, EDX, AFM, Water Contact Angle, ATR-FTIR, and Solid (CP-MAS) 13C NMR revealed various chemical and structural features of the membrane. The membrane M2 (PAAH-IPC) (exhibited >98% rejection for various anionic and cationic dyes. The inclusion of SDS during interfacial polymerization led to a substantial 3-fold increase in methanol permeate flux from 31 L m−2 h−1 to 119 L m−2 h−1, at a pressure of 15 bar. Conversely, the addition of CTAB resulted in membranes with higher permeate flux but insufficient dye rejection. Moreover, after three weeks of static aging of the membranes no significant changes were detected in either permeability or solute rejection, substantiating the stability of membranes.

Fe3+-modified polyamide membrane with a porous network structure: Rapid permeation and efficient interception of trace organic compounds

Forward osmosis (FO) is a promising technology in the treatment of trace organic substances. However, the development of this technology is limited by membrane material selection and the long-term chemical stability and durability of the membrane. Whereas ibuprofen, a representative trace organic substances that is hydrophobic and negatively charged, poses potential environmental hazards due to its bioactivity. In this work, polyethersulfone (PES) membranes were modified with iron metal complexes via chelation reactions to achieve high rejection rates for ibuprofen. The Fe3+-modified composite FO membrane increased the ibuprofen rejection rate to 98.3 % compared to less than 80.0 % for the original PES membrane. Additionally, the modified membrane enhanced water flux by at least 25.0 % and reduced reverse solute flux to a maximum of 73.0 % of that of the polyamide composite membrane, while significantly improving anti-fouling capabilities. Membrane characterization results revealed that the significant enhancement in the ibuprofen retention rate was due to the addition of a negative charge by forming complexes with Fe3+, which increased intermolecular interactions. Additionally, the dense network structure developed by the Fe3+-EDTA-2Na modification also contributed to the enhanced membrane performance.

Novel highly permeable ultrathin polyamide composite membrane with interfacial polymerization of 4,6-diaminoresorcinol for molecular separation

Developing ultrathin polyamide thin-film composite (PA TFC) membrane with ultrahigh performance to overcome the perm-selectivity upper bound of molecular separation is still the major challenge for practical applications. Herein, we first designed an ultrahigh performance PA TFC membrane fabricated by interfacial polymerization of 4,6-diaminoresorcinol dihydrochloride (DAR) and trimethyl chloride (TMC) on the substrate. The structural morphology of the PA active layer and the separation performance of the resultant membrane were tuned by DAR dosage. This ultrathin PA TFC membrane breaks the trade-off between water permeance and dye (NOM) selectivity. Accordingly, the optimal membrane had a water flux of 212.5 LHM/bar with superior rejection of 98.6 % and 100 % for BBR and CR, respectively, surpassing the upper-bound limit of most reported polymeric membranes thus far. The membranes also exhibited a high salt passage (>95 %), achieving an impressive screening capacity for the dye/salt mixture as well as excellent antifouling and operation stability performance. This work sheds light on the regulation of the PA selective layer via new amine monomer featuring ultrahigh performance.

New strategy for structure rearrangement of thin-film composite (TFC) polyamide (PA) membranes and offering potential use in both aqueous and organic solvents

The purity of sodium hexafluorophosphate (NaPF6) is crucial for the preparation of electrolytes in manufacturing. We propose a simple process in order to induce membrane structure rearrangement process (SRP) by activating thin-film composite (TFC) membranes with polyamide (PA) structure and explore their potential green recycling application in concentrating sodium-ion batteries (SIBs) electrolyte. The method utilizes a solution containing polar aprotic solvent as the soaking and activating solution to swell and disintegrate the loosely cross-linked PA layer, and a non-solvent solidification solution complete the SRP, enhancing the permeability of the PA layer while maintaining high rejection rates for divalent ions. Subsequently, during the further treatment of the membrane surface in structure rearrangement, tert-butanol (TBA) is introduced into the aqueous solution to reconstruct the surface PA layer, further improving the permeability. The optimal D8010T10 achieved a permeation flux of 24.2 L m−2 h−1·bar−1, with rejection rates for sodium sulfate (Na2SO4), magnesium chloride (MgCl2), and magnesium sulfate (MgSO4) reaching 94.7 %, 98.4 %, and 99.1 % respectively. And the mechanism of SRP with different solvent is analyzed and explained through dissipative particle dynamics (DPD) simulations. This study provides a commercially viable approach for manufacturing high-performance membranes. The D8010T10 membrane achieves more than 90 % separation efficiency for sodium hexafluorophosphate (NaPF6) dissolved in different solvents, providing a potential solution for the concentration and recovery of NaPF6 in lab-scale, verified its potential use in the organic solvent nanofiltration (OSN) and a path way for waste membrane recycling and degrading use in the industry.

Anti‐fouling capacity enhancement of thin‐film composite polyamide membrane by chitosan graft polymerization methods

AbstractThis study aimed to improve the anti‐fouling properties of a thin‐film composite polyamide membrane by modifying it with chitosan and acrylic acid using UV‐induced and Redox‐initiated graft polymerization methods. The modified membrane's separation performance was evaluated by measuring the flux and retention of sodium ions in water during filtration. The anti‐fouling capacities of the modified membranes were determined by measuring the maintained flux ratios and irreversible fouling factors during the 8‐h filtration of aqueous solutions of sodium chloride at different concentrations (1000 and 10,000 ppm). In addition, by evaluating the membrane's surface properties using various methods, including field emission scanning electron microscopy, attenuated total reflection – Fourier transform infrared spectroscopy, and water contact angle measurements, we have demonstrated the validity of the experimental results. Our results showed that the grafted membranes under UV irradiation or redox initiators had enhanced anti‐fouling properties while maintaining salt retention. The modified membranes fabricated by UV‐induced or Redox‐initiated technique had superior anti‐fouling capabilities, with irreversible fouling factors and maintained flux ratios of around 8% and 43%, respectively, after 8 h of filtration, compared to only 12% and 36% for the unmodified membrane. These findings suggest that the modified membranes have the potential for use in filtration systems to prevent the fouling phenomenon.

Manipulating the monomers supply of interfacial polymerization towards the ultrathin polyamide composite membrane for CO2 capture

Preparing polyamide (PA) composite membranes with high gas separation performance requires rational control for the interfacial polymerization (IP) process. In this study, the monomer supply of piperazine (PIP) and trimesoyl chloride (TMC) in the IP process was precisely manipulated to generate an ultrathin PA film on the polydimethylsiloxane (PDMS) gutter layer for CO2 separation. Concretely, the PIP supply was regulated from the homogeneous, slow, and excess mode to the inhomogeneous, fast, and small mode by constructing a sodium dodecyl sulfate (SDS) array at the phase interface; subsequently, the TMC supply was increased by elevating the TMC concentration. Therefore, the amine-to-acid chloride concentration ratio in the reaction zone was optimized and, as a consequence, the IP reaction rate was significantly increased. As a result, the thickness of the PA film was reduced from ∼92 nm to ∼37 nm through the optimization of SDS and TMC concentrations, and accordingly, the CO2 permeance was increased from 501 GPU to 1498 GPU under 0.1 MPa without sacrificing selectivity. Moreover, the membrane preparation efficiency was greatly improved with an IP reaction time of less than 30 s. The insights provided could promote the industrial application of interfacial polymerization in the scale-up preparation of high-performance CO2 separation membranes.

Enantiomeric separation of tryptophan via novel chiral polyamide composite membrane.

The separation of chiral drugs continues to pose a significant challenge. However, in recent years, the emergence of membrane-based chiral separation has shown promising effectiveness due to its environmentally friendly, energy-efficient, and cost-effective characteristics. In this study, we prepared chiral composite membrane via interfacial polymerization (IP), utilizing β-cyclodextrin (β-CD) and piperazine (PIP) as mixed monomers in the aqueous phase. The chiral separation process was facilitated by β-CD, serving as a chiral selective agent. The resulting membrane were characterized using SEM, FT-IR, and XPS. Subsequently, the chiral separation performance of the membrane for DL-tryptophan (Trp) was investigated. Lastly, the water flux, dye rejection, and stability of the membrane were also examined. The results showed that the optimized chiral PIP0.5β-CD0.5 membrane achieved an enantiomeric excess percentage (ee%) of 43.0% for D-Trp, with a solute flux of 66.18 nmol·cm-2·h-1, and maintained a good chiral separation stability. Additionally, the membrane demonstrated positive performance in the selective separation of mixed dyes, allowing for steady operation over a long period of time. This study offers fresh insights into membrane-based chiral separations.