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A key challenge in efficient molecular separation is fabricating large‐scale, highly selective polymeric membranes with precise pore control at the molecular scale. Herein, a new contorted monomer 6,6′‐dihydroxy‐2,2′‐biphenyldiamine (DHBIPDA) is introduced as a building block to generate cross‐linked, ultra‐thin microporous nanofilms (sub‐10 nm) via interfacial polymerization, enabling rapid, and precise molecular nanofiltration. Using diacyl chloride (TPC) as the cross‐linker instead of trimesoyl chloride (TMC) significantly reduces the pore sizes within the membranes and achieves a narrower pore distribution due to a semi‐crystalline structure. The film structures are confirmed using comprehensive characterization techniques including wide‐angle X‐ray scattering (WAXS), X‐ray diffraction (XRD), positron annihilation lifetime spectroscopy (PALS), CO2 adsorption analysis, and molecular‐scale simulation. The DHBIPDA/TPC and DHBIPDA/TMC membranes achieve methanol permeance values of up to 16.4 and 15.1 LMH bar−1 coupled with molecular weight cutoffs (MWCOs) as low as 283 and 306 Da, respectively. The DHBIPDA/TPC membrane demonstrates both higher permeance and higher selectivity compared to its relatively disordered counterpart DHBIPDA/TMC, consistent with characterization data. The DHBIPDA‐derived membrane efficiently separates dye mixtures with similar molecular weights and enables effective recycling of organometallic homogeneous catalysts, suggesting its potential for industrial applications. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) plays important roles in pharmaceutical ingredients purification and solvent recovery. However, the low organic solvent permeance under cross‐flow operation of OSN membrane hampers their industrial applications. Herein, we report the construction of coffee‐ring structured membrane featuring high OSN permeance. A water‐insoluble crystal monomer that dissolved in EtOH/H2O mixed solvent was designed to react with trimesoyl chloride via interfacial polymerization. Owing to the diffusion of EtOH to n‐hexane, coffee‐ring nanostructure on the support membrane appeared, which served as the template for construction of coffee‐ring structured membrane. The optimal nanostructured membrane demonstrated 2.6‐fold enhancement in the effective surface area with reduced membrane thickness. Resultantly, the membrane afforded a 2.7‐fold enhancement in organic solvent permeance, e.g. ~13 LMH/bar for MeOH, without sacrificing the rejection ability. Moreover, due to the rigid monomer structure, the fabricated membrane shows distinctive running stability in active pharmaceutical ingredients purification and the ability for concentration of medicines. [ABSTRACT FROM AUTHOR]

• PDA-HKUST-1 interlayer enhances the stability of OSN membrane structure. • PA layer thickness of PA/ PDA -HKUST-1 0.6 /PEI membrane is about 14 nm. • PA/CaAlg-HKUST-1 6 /PEI membrane has good solvent resistance. Polydopamine (PDA) and metal-organic skeleton HKUST-1 were co-deposited on the base membrane of hexamethylenediamine (HDA)-crosslinked polyetherimide (PEI) ultrafiltration membrane as the interlayer, and high-throughput organic solvent nanofiltration membrane (OSN) was prepared by interfacial polymerization and solvent activation reaction. The polyamide (PA) layer surface roughness from 28.4 nm in PA/PEI to 78.3 nm in PA/PDA-HKUST-1 0.6 /PEI membrane, reduced the thickness of the separation layer from 79 to 14 nm, and significantly improved the hydrophilic, thermal and mechanical properties. The flux of the PA/PDA-HKUST-1 0.6 /PEI membrane in a 0.1 g/L Congo Red (CR) ethanol solution at 0.6 MPa test pressure reached 21.8 L/(m2·hr) and the rejection of CR was 92.8%. Solvent adsorption test, N, N-dimethylformamide (DMF) immersion experiment, and long-term operation test in ethanol showed that the membranes had high solvent tolerance. The solvent flux test demonstrated that, under the test pressure of 0.6 MPa, the flux of different solvents ranked as follows: methanol (56.9 L/(m2·hr)) > DMF (39.6 L/(m2·hr)) > ethanol (31.2 L/(m2·hr)) > IPA (4.5 L/(m2·hr)) > N - hexane (1.9 L/(m2·hr)). The ability of the membranes to retain dyes in IPA/water dyes solution was also evaluated. The flux of the membrane was 30.4 L/(m2·hr) and the rejection of CR was 91.6% when the IPA concentration reached 50%. This OSN membrane-making strategy is economical, environment-friendly and efficient, and has a great application prospect in organic solvent separation systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Hollow fiber (HF) organic solvent nanofiltration (OSN) membranes have recently attracted significant interest in the field of membrane technology. Their popularity stems from comparative advantages, such as high packing density, fouling resistance, and easier scalability for larger applications, unlike flat-sheet/spiral-wound OSN membranes, which may present challenges in these aspects. The combination of interfacial polymerization (IP) and HF configuration has opened up new opportunities for developing advanced membranes with enhanced separation performance that can be tailored for various OSN applications. The objective of this review is to discuss the latest advancements in developing thin film composite (TFC) HF membranes, with a focus on the IP method. Novel materials and processes are discussed in detail, emphasizing the fabrication of greener, interfacially polymerized HF OSN membranes. In addition, the commercial viability and limitations of TFC HF membranes are highlighted, providing perspectives on future research directions. [ABSTRACT FROM AUTHOR]

Herein, thin‐film composite membranes consisting of poly(m‐phenyleneisophthalamide) substrate and polyamide active layer were constructed by transition metal ion‐assisted interfacial polymerization method. As compared to the traditional polyamide membranes, a much thinner polyamide layer (33 vs. 200 nm) can be synthesized with higher permeance (3.2 vs. 0.62 L m−2 h−1 bar−1) in the organic solvent nanofiltration. Similarly, the prepared membranes maintained a high rejection (>99%) for various dyes. Optimal membranes prepared by using Co2+ exhibited strong tolerance to various organic solvents with good long‐term stability. Positron annihilation spectroscopy and other characterization methods were used to investigate the relationships between the membrane microstructures and the enhanced separation performance. Based on molecular dynamics simulation, it was found that the diffusion coefficient of polyethyleneimine monomer decreased by about 18 times after adding Co2+ to the aqueous solution (forming coordination interaction). This procedure has great potential and sustainability for practical organic solvent nanofiltration applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Organic solvent nanofiltration membranes are reviewed. • Discussed the role of functionalization and covalent crosslinking in membrane. • Covalent incorporation of organic, inorganic, and hybrid materials is described. • New OSN membranes incorporating 2D nanomaterials are discussed. • The challenges and prospects around OSN membranes are discussed. Organic solvent nanofiltration (OSN) membranes have gained significant attention owing to their pivotal role in various industrial applications, including pharmaceuticals, fine chemicals, and manufacturing. This review provides a comprehensive overview of the recent advances in OSN membrane technology, focusing on membrane materials, fabrication techniques, and strategies for tuning the chemistry, structure, and performance of OSN membranes. Initially, the fundamental principles underlying OSN are described, highlighting the critical parameters influencing membrane selectivity, permeability, and stability in organic solvents. It also focuses on the importance of covalent crosslinking in the design and fabrication of dense polyamide membranes. Subsequently, the design and synthesis of novel membrane materials are discussed, including polymeric, inorganic, and hybrid membranes. The use of 2D nanomaterials is summarized, with an emphasis on their structural characteristics and tailored properties for solvent separation applications. We further explored the innovative fabrication strategies, such as interfacial polymerization, modification of ultrafiltration supports, and tuning of the active layer chemistry by incorporating the membrane structure with porous nanofillers. This review also discusses the inhomogeneity issues between inorganic nanofillers and organic matrices of membranes as well as the strategies to overcome these limitations through proper functionalization. Finally, we identified emerging trends and prospects in OSN membrane research, encompassing sustainability, scalability, and integration with other membrane processes, to address existing challenges and discover new opportunities for efficient solvent separation in diverse industrial sectors. [ABSTRACT FROM AUTHOR]

Microporous organic polymers (MOPs) featuring chemically rigid backbones and permanent micropores are desirable for fabricating molecular selective membranes towards organics separation. However, coordinating facile film processing with high micropore persistence remains a challenge. In this paper, a low molecular weight polymers of intrinsic microporosity was rationally designed by precisely controlling the stoichiometric equilibrium of polymerization monomer. The polymers of intrinsic microporosity oligomers combine rigid and contorted structures with the aqueous solution processability, promoting the formation of 25-nm-thick polyaramide nanofilms with enhanced microporosity via support-free interfacial polymerization (SFIP). The resulting composite membranes have superior retention of small molecular solutes and high nonpolar and polar solvent permeances. Experiment and simulation results show that their excellent separation performance is due to substantially open and interconnected microporosity formed in the polymer networks based on rigid and contorted diamines as well as reduced film thickness. This study provides a new sight for using MOPs to construct high-microporosity membranes for precise and rapid molecular sieving. [Display omitted] • A novel rigid molecule that polymers of intrinsic microporosity oligomer (APIMO) was rationally designed. • APIMO was employed as the building block for constructing thin film via support-free interfacial polymerization. • The resultant thin film composite membrane displayed superior permeances of both nonpolar and polar solvents. [ABSTRACT FROM AUTHOR]

The development of highly permeable and selective thin-film composite (TFC) membranes is essential for organic solvent nanofiltration (OSN) applications. However, overcoming the permeability–selectivity trade-off in polymer membranes remains highly challenging owing to the difficulty in controlling the thickness and nanostructures of the selective layers. In this study, TFC OSN membranes with sandwich-like structures were developed via interfacial polymerization on Cu-TCPP nanosheet-modified microporous polyvinylidene fluoride (PVDF) substrate surface. The interfacial polymerization was done by using mixed amine (polyethyleneimine and piperazine) in the aqueous phase and the 1,3,5-benzenetricarbonyl trichloride in the hydrophobic ionic liquid phase as monomers. It was found that the Cu-TCPP nanosheets of micrometer lateral dimensions and nanometer thickness (1.5 ± 0.6 nm) can be deposited on the PVDF substrate as an interlayer to facilitate the following interfacial polymerization reaction. The Cu-TCPP interlayer also can be served as a binder between the polyamide selective layer and the microporous PVDF substrate to enhance their mechanical strength. As compared with the PVDF/PA membrane, the PVDF/t-Cu-TCPP/PA membrane exhibited higher elongation (8.0 vs. 4.6%) while ensuring slightly lower tensile strength (36.0 vs. 48.6 MPa). Under optimal synthetic conditions, the TFC membranes could achieve 2.7 L m–2 h–1 bar–1, and 98.9% and 95.0% rejection to Brilliant Blue R (826 Da) and Congo red (697 Da), respectively, in ethanol. Furthermore, the membranes showed steady performance throughout the 36 h nanofiltration of the Rose bengal/ethanol mixture and exhibited good performance in the concentration of lecithin in methanol. Accordingly, this work highlights the potential of using thin metal–organic framework nanosheets as interlayers to develop high-performance TFC membranes for OSN applications. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is an emerging membrane separation technology, which urgently requires robust, easily processed, OSN membranes possessing high permeance and small solutes‐selectivity to facilitate enhanced industrial uptake. Herein, we describe the use of two 2,2′‐biphenol (BIPOL) derivatives to fabricate hyper‐crosslinked, microporous polymer nanofilms through IP. Ultra‐thin, defect‐free polyesteramide/polyester nanofilms (≈5 nm) could be obtained readily due to the relatively large molecular size and ionized nature of the BIPOL monomers retarding the rate of the IP. The enhanced microporosity arises from the hyper‐crosslinked network structure and monomer rigidity. Specifically, the amino‐BIPOL/PAN membrane exhibits extraordinary permselectivity performances with molecular weight cut‐off as low as 233 Da and MeOH permeance of ≈13 LMH/bar. Precise separation of small dye mixtures with similar M.W. based on both their charge and molecular size are achieved. [ABSTRACT FROM AUTHOR]

Highly permeable polyamide (PA) membranes with precise molecular sieving capabilities are crucial for energy-efficient chemical separations. There is a critical need to design solvent-stabilized membranes with enhanced permeance to improve separation efficiency. In this work, we propose a novel anhydrous interfacial polymerization (IP) method, where flexible polyethyleneimine (PEI) and rigid p-phenylenediamine (PPD) are uniquely dissolved in isopropanol (IPA) and subsequently crosslinked with trimethyl chloride (TMC) in situ to fabricate high-performance PA membranes. Notably, the use of IPA as a solvent represents a significant advancement in membrane fabrication. This approach resulted in PA membranes with a relatively loose selective layer compared to traditional PA membranes, allowing for exceptionally high solvent permeance while maintaining strong rejection performance in organic solvent nanofiltration (OSN). The obtained PEI + PPD/TMC PA membranes demonstrated outstanding ethanol (EtOH) permeance of 46.44 L m−2 h−1 bar−1 in the organic solvent system, along with good rejection for small organic molecules, such as 93.84% for Eriochrome Black T (EBT, 461.38 Da). In addition, the performance of the PEI + PPD/TMC PA membranes remained at a high level even during 510 min of continuous cross-flow filtration, under high pressure (5 bar) testing, and after 6 cycles of separation, which demonstrated their good stability in long-term service. This work establishes a robust foundation for employing anhydrous IP reactions and innovative solvent systems, such as IPA, to develop high-permeance PA membranes. [Display omitted] • Isopropanol (IPA) is a solvent for amine monomers to induce anhydrous interfacial polymerization. • The PA membranes exhibited excellent selectivity for APIs (>80 %) and various dyes (MW > 461.38 Da, rejection > 93.84 %). • The PEI + PPD/TMC PA membranes own ultra-high permeance, the EtOH permeance up to 46.44 L m−2 h−1 bar−1. • The membranes still showed good separation performance after high pressure, multiple cycles, and long filtration time. [ABSTRACT FROM AUTHOR]

A facile strategy to synthesize ultrathin polyamide membranes with ultrafast solvent transport and tunable molecular sieving property via alkyl-chain engineering strategy is reported. The introduction of flexible alkyl chains can effectively tune the chemical property of the membrane and tailor the pore size distribution as well. [Display omitted] • The alkyl-chain-engineered membranes demonstrate exceptional solvent permeance. • The alkyl-chain-engineered membranes has excellent dye separation performance. • The MWCO of the membranes can be controlled by grafting different alkyl chains. • The membranes outperform state-of-the-art OSN membranes used in non-polar solvents. • The membranes show excellent performance in hydrocarbon separation. Organic solvent nanofiltration (OSN) has emerged as a promising separation technology for the chemical and pharmaceutical industries due to its low energy consumption and eco-friendliness. However, traditional polyamide-based membranes used in OSN often exhibit low permeance for organic solvents and it is difficult to precisely control the pore structure. In this study, we report a facile approach to fabricate ultrathin alkyl-chain-engineered polyamide nanofilms via free-standing interfacial polymerization for high-performance selective separations. The membranes were prepared via a "two birds one stone" strategy, enabled by post-treatment in aliphatic amine solution, simultaneously regulating the pore size and optimizing the membrane chemical property. This enables the membrane with high solvent permeance, especially for non-polar solvents (heptane at ∼22.2 L m−2h−1 bar−1, toluene at ∼16.8 L m−2h−1 bar−1), while maintaining excellent molecular sieving capability. Notably, the molecular weight cut-off (MWCO) can be regulated by introducing alkyl chains of varying lengths to their pores. The exceptional solvent permeance and tunable molecular sieving property make the membranes promising for high value-added products purification in the pharmaceutical industry and crude oil separation. [ABSTRACT FROM AUTHOR]

For thin-film composite (TFC) membranes applied in organic solvent nanofiltration (OSN), enhancing the adhesion between the active layers and the substrates can effectively improve the stability of the membranes. In this work, TFC OSN membranes with polyetherketone bearing amino group (PEK-NH 2) asymmetric substrates and amino-contained polyarylate active layers were fabricated by interfacial polymerization technique, and subsequently reacted with dialdehydes to form crosslinking between and within the substrates and the active layers. Crosslinking improved both of the solvent resistance of the substrates and the separation selectivity of the active layers. In addition, reverse pressure testing demonstrated that crosslinking allowed the active layers to adhere more strongly to the substrates. The optimized integrally crosslinked membranes exhibited methanol permeance of 10.4 L m−2 h−1 bar−1 and a molecular weight cut-off of about 320 g mol−1 in methanol. Moreover, the integrally crosslinked membranes maintained good stability for OSN operation in methanol for 12 days, and also exhibited unchanged OSN performance after soaked in N,N -dimethylformamide for 2 days. This work demonstrated a novel solvent-resistant membrane material and membrane-fabrication strategy with prospect for OSN application. Schematic illustration of integrally crosslinking. [Display omitted] • Glutaraldehyde reacts with amino groups both in two layers to achieve integrally crosslinking. • Crosslinking within the active layer enhances the selectivity of the TFC membrane. • The adhesion between the active layer and the substrate is enhanced by integrally crosslinking. • The membrane shows methanol permeance of 10.4 L m−2 h−1 bar−1 with MWCO down to 320 g mol−1. [ABSTRACT FROM AUTHOR]

• 7,7′-OH-BINOL and diacyl chloride were used to prepare TFC OSN membranes. • The formed polyarylate layer show thin and high microporosity characters. • Two oil phase cross-linker result in nanofilms with diverse microstructures. • The optimal membrane shows methanol flux of 5.81 LMH/bar and MWCO of 288 Da. In recent years, OSN technology has gained great attention for its environmental friendly nature, energy efficiency, and small carbon footprint. Herein, we prepared TFC OSN membranes BINOL-TPC and BINOL-IPC with higher selectivity by employing a contorted molecule 7,7′-dihydroxy-2,2′-binaphthol (7,7′-OH-BINOL) with four functional groups and diacyl chloride (TPC/IPC) via interfacial polymerization (IP) method compared to with trimesoyl chloride (TMC). The use of monomer 7,7′-OH-BINOL with rigid, twisted and multiple reaction sites endow the resulted polyarylate layer with high microporosity and cross-linking density. Notably, the BINOL-TPC and BINOL-IPC membranes exhibited good performance in retaining small molecular solutes, with MWCO values of 288 and 344 Da, respectively. Meanwhile, the methanol permeance of the two composite membranes reach 5.81 and 7.06 LMH/bar, respectively. In addition, the membrane BINOL-TPC could achieve precise separation of mixed dyes with similar molecular weight but opposite charge. As can be seen, by designing and utilizing IP monomers with different structures and functionalities, it is possible to fabricate membranes with diverse microstructures and properties, ultimately leading to varied separation performances. This research offers some new insights in the view of molecular-level tailoring for the fabrication of high performance OSN membranes. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) technology has the potential to separate and purify organic solvents in high efficiency. The self-supporting structure and ease scaling-up merit of hollow fiber (HF) type membrane make it an attractive option for OSN application. Nevertheless, low solvent permeance is one of technical limitation in conventional HF OSN membranes due to their excessively dense separation layer and limited free volume. Herein, we propose a straightforward methodology to fabricate HF thin-film composite (TFC) OSN membranes having exceptional solvent permeance and solute rejection. This methodology is conducted through the incorporation of macrocyclic molecules, 1,4,7,10-tetraazacyclododecane (Cyclen), into the aqueous monomer solution of m -Phenylenediamine (MPD) during the interfacial polymerization to modulate the separation layer. In this way, the average pore size of the separation layer could be precisely enlarged and narrowed on a sub-nanometer scale. Consequently, the Cyclen-modulated HF TFC OSN membrane exhibits excellent separation performance, with a pure methanol permeance of 76.7 L m−2 h−1 MPa−1 and a pure ethanol permeance of 26.5 L m−2 h−1 MPa−1, which is nearly 60 % increase compared with the baseline TFC membrane, while the Rhodamine B (RDB) rejection only shows a neglectable decrease from 99.7 % to 99.6 % at optimal fabrication conditions. Furthermore, the optimal membrane exhibits remarkable solvent resistance, withstanding a 35 d immersion in N, N -dimethylformamide (DMF) at room temperature without a significant decline in RDB rejection. Additionally, the optimal membrane shows higher than 99 % rejection for Rifampicin (823 Da), which is considerable potential for applications in the separation and recovery of pharmaceuticals. In summary, incorporating macrocyclic polyamine Cyclen into the polyamide layer is a viable method for regulating the physical structure and strengthening the performance of HF OSN membrane. [Display omitted] • Hollow fiber OSN membrane doped with macrocyclic polyamine Cyclen. • The incorporation of Cyclen results in an enlarged average pore size. • Ethanol permeance increases nearly 60 % with Rhodamine B rejection of 99.6 %. • No significant decrease in Rhodamine B rejection during 35 d immersion in DMF. [ABSTRACT FROM AUTHOR]

Biomass-based thin film composites (TFCs) fabricated only from abundant natural resources are emerging as next-generation organic solvent nanofiltration membranes. However, most of the existing membrane fabrication processes still use toxic chemicals, harsh solvents, and fossil-based supports. We report a plant-based, green TFC membrane based solely on sustainable resources. It is the thinnest defect-free nanofilm (only 12-nm-thick) fabricated only from natural resources. Dialdehyde starch was crosslinked with priamine at the interface of a water–eucalyptol solvent system. Interfacial polymerization occurred on a biodegradable cellulose acetate support obtained using phase inversion. The membrane has an ultrathin (12-nm-thick) selective layer, and the molecular weight cut-off and permeance were fine-tuned between 366 and 624 ​g ​mol−1 and 7 and 23 ​L ​m−2 ​h−1 ​bar−1, respectively. Stable nanofiltration performance under continuous crossflow filtration was achieved for seven days. The sustainability of the membrane fabrication platform was compared with those of other platforms. Our TFC membrane fabrication platform enables the conversion of biomass-based building blocks into high-value-added products.

Efficient separation of aromatic‐aliphatic hydrocarbon mixtures has long been an important topic in chemical industries. Organic nanofiltration (OSN) has been revealing great promise in separating solvent mixtures that has not been effectively resolved by the state‐of‐the‐art technologies. Herein, novel OSN membranes are designed for the separation of toluene and n‐heptane. Polyamide active layer with diaminonaphthalene as the aqueous phase monomer is prepared by interfacial polymerization for the first time. The addition of polydimethylsiloxane gutter layer, as well as the combination of spin coating technique and macroporous substrate, renders the membranes with loose and defect‐free architectures. The as‐designed membranes achieve a rather high selectivity of toluene over n‐heptane (>4) together with ultra‐high toluene permeance (>180 L m−2 h−1 bar−1). These membranes also present excellent stability in the long‐term operation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The nanoscale ordered "Turing-like" structure of PA/PPy composite membrane was achieved by PA interlayer assistance of CVD method. • PA/PPy composite membrane still showed excellent tolerant at high temperature (80 ℃) and organic solvent (DMAc). • The excellent stability was obtained due to hydrogen bond and electrostatic interaction between PA and PPy. • The membrane presented excellent permselectivity performances with MWCO as low as 185 Da. Organic solvent nanofiltration (OSN) is a green, energy-saving, and highly efficient emerging membrane separation technology, and there is an urgent need for robust, easy-to-process OSN membranes with high permeance and small solute selectivity for industrial applications. Herein, we propose a new strategy for accurately designing novel OSN membranes. Specifically, a polyamide (PA) interlayer was synthesized in-situ on the surface of homogeneous reinforced poly(p-phenylene terephthamide) (PPTA) hollow fiber membrane by interfacial polymerization (IP) using both ultra-low concentrations piperazine (PIP, 0.05 wt%) and trimesoyl chloride (TMC, 0.005 wt%), and then a defect-free and dense PPy layer was deposited on top of the hydrophilic PA interlayer by chemical vapor deposition (CVD) process to prepare PA/PPy composite membranes with spherical cluster or strip cluster "Turing-like" structure. The resulting PA/PPy composite membranes presented an excellent high selective permeability, the dimethylacetamide (DMAc) permeability was 21.1 L·m−2·h−1·MPa−1, and the molecular weight cut-off (MWCO) was as low as 185 Da. A 30-hour OSN test at elevated temperatures (80 °C) and in organic solvent (DMAc), as well as a one-month immersion test in ethanol and DMAc at room temperature, demonstrated superior separation performance and structural stability of the membranes, indicating their application potential in harsh solvent systems. Our novel method for developing nanoscale ordered structured PA/PPy composite membranes offers great potential for the development of multilevel structural designs in the preparation of high-performance OSN membranes with potential industrial applications. [ABSTRACT FROM AUTHOR]

The development of isothermal refining processes is important because of the high energy demands of crude oil separation. Membrane technology provides separation efficiency and low carbon footprint. This efficiency can be fine-tuned and enhanced by modifying the chemistry of the membrane selective layer. Herein, we describe the fabrication of membranes by interfacial polymerization using a combination of contorted fluorinated monomer bearing six fluorine atoms and trimesoyl chloride in the organic phase. A fluorinated m -phenylene diamine was added to the aqueous phase. This approach produces membranes with high surface roughness, increases their hydrophobicity and promotes the transport of hydrocarbons with high selectivity and toluene permeance (15.6 L m−2 h−1 bar−1). Successful evaluations were conducted for the fractionation of crude oil, confirming the potential for application in the petrochemical industry. [Display omitted] • Interfacial polymerization membranes with fluorine-functionalized contorted acid chloride. • Fluorinated monomers yield hydrophobic membranes for organic solvent nanofiltration. • Fluorinated monomers boost crude-oil separation performance in isothermal refining. • Successful high-flux hydrocarbon separation and crude oil fractionation. [ABSTRACT FROM AUTHOR]

Separation and purification on molecular level from organic solvent mixtures are of paramount importance in industries. Organic solvent nanofiltration (OSN) is a pressure‐driven membrane separation process providing an attractive alternative to conventional energy‐intensive technologies. However, devising a solvent stable, scalable membrane with high permeability and excellent selectivity is still a challenge. Interfacially polymerized thin‐film composite (TFC) OSN membranes integrating an ultrathin selective layer and a porous substrate layer are expected to revolutionize advanced membrane separations. New materials and new strategies to achieve a solvent resistant, highly permeable, and highly selective membrane have been developed in recent years. This review analyses the development of the state‐of‐the‐art interfacially polymerized TFC OSN membranes from the view of structures, materials, and methodologies. First, the emerging structures of current TFC OSN membranes are discussed. The exploitation of new materials (polymers, (nano)fibers, inorganic materials) for the preparation of substrate layer is updated. The advances of new aqueous/organic monomers for synthesis of the selective layer are summarized. Furthermore, the proposed strategies for designing permselective TFC membranes are highlighted. Finally, the challenges together with the future prospects of interfacially polymerized TFC membranes for OSN are proposed. [ABSTRACT FROM AUTHOR]

The integration of high permeability and exceptional selectivity, thereby overcoming the conventional "trade-off" effect, remains a persistent challenge for the practical implementation of organic solvent nanofiltration (OSN) membranes. Herein, at the molecular level of design, we utilized the 5,5′-diamino-2,2′-biphenol (amino-BIPOL) and diacyl chloride as IP monomers to prepare OSN membranes with high perm-selectivity. The amino-BIPOL, a contorted biphenol molecule with four reactive sites, serves as a molecular-level unit to hinder efficient packing of polymer chains and induce the formation of interconnected micropores in the resulting polyesteramide layers. By employing diacyl chloride terephthaloyl dichloride (TPC) and isophthaloyl dichloride (IPC) as the oil-phase cross-linker, two kinds of TFC membranes were prepared. The resulting membranes both present smooth surface morphology, with ultrathin and high microporous selective layer allowing for efficient mass transfer. Specifically, the methanol permeance of amino-BIPOL/TPC and amino-BIPOL/IPC membrane reaches up to 15.1 and 15.6 LMH/bar, while maintaining a molecular weight cut-off (MWCO) value of 300 and 373 Da, respectively. Overall, this work illustrates the different oil-phase cross-linkers will result in diverse nanofilm microstructure and thus with distinct perm-selectivity properties, offering new insights for the design and modification of advanced OSN membranes. [Display omitted] • Amino-BIPOL and diacyl chloride were used to prepare TFC OSN membranes by IP method. • The membranes present high micropores and ultrathin characteristics. • Two oil phase cross-linker result in nanofilms with diverse cross-linked network. • The optimal membrane shows methanol permeance of 15.1 LMH/bar and MWCO of ∼300 Da. [ABSTRACT FROM AUTHOR]

The petrochemical industry is typically energy-intensive, involving frequent and intricate separation processes. SINOPEC is a globally recognized lubricant manufacturer and distributor, with a substantial production capacity exceeding 1.7 million tonnes in 2022. The dewaxing solvent recovery process in lubricant production necessitates a multi-stage flash and distillation treatment, resulting in substantial energy consumption and high costs. Utilizing organic solvent nanofiltration (OSN) membranes offers a feasible alternative approach to address this issue. A series of thin film composite OSN membranes with varying molecule weight cut-offs were prepared through precise adjustment of the chemical composition and proportion of the organic co-monomers. The application potential of the optimized membranes in the lubricant dewaxing solvent recovery was evaluated using lubricant base oil derived from the actual production line, specifically light deasphalted oil and vacuum cut2. The membrane exhibited a rejection of 99.3 % for light deasphalted oil and 95.6 % for vacuum cut2, with corresponding fluxes of 16.8 and 13.4 LMH under 2 MPa, respectively. Based on this, spiral-wound membrane modules (1.8″ × 12″) were fabricated and their suitability for dewaxing solvent recovery was further validated. The fabrication of spiral-wound membrane modules (8″ × 40″) is in progress, with intentions to conduct a pilot plant trial on the lubricant oil manufacturing line. [Display omitted] • Spiral-wound membrane modules are reported for dewaxing solvent recovery. • The membrane exhibits a high rejection of 99.3 % for light deasphalted oil. • A 1.8″ × 12″ sized membrane module generates 7.1 L dewaxing solvent per hour. • A pilot trial using 8″ × 40″modules on the lube oil production line is in plan. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) membranes have become a powerful separation platform in a myriad of chemical and pharmaceutical fields owing to their superior merits in high separation efficiency and low energy consuming. Despite extensive progress in exploiting polyamide thin film composite (TFC) membranes for OSN, they are heavily limited by inferior solvent permeability, especially when using conventional low-porous polyimide as TFC substrate. Herein, we report a facile substrate engineering strategy to leverage macro-porous Nylon66 microfiltration membrane to replace the conventional low-porous polyimide substrates for fabricating TFC membranes by interfacial polymerization, enabling high and robust solvent permeability during OSN. Distinct from conventional polyimide, Nylon66 substrates take advantage of their high porosity, macro-porous size and excellent hydrophilicity to realize more monomers storage and uniform monomers distribution, allowing to create crumpled and defect-free polyamide layers. With this method, the polyamide TFC membranes show a 2.1-fold increase in ethanol permeance (up to 16.0 L h−1 m−2 bar−1) meanwhile possessing 98 % rejection of dye, surpassing the most reported TFC membranes. We also demonstrate that the TFC membranes exhibit excellent long-term stability in both polar and non-polar solvent, as well as hold huge promise in the precise separation of dye mixture, pharmaceutical ingredient, and catalyst. [Display omitted] • Nylon 66 substrate is first used to prepare TFC-based organic solvent nanofiltration membranes. • TFC membranes using Nylon 66 substrate feature crumpled and defect-free polyamide layer. • TFC membranes show an ultrahigh ethanol permeance of 16.0 L h−1 m−2 bar−1 and 98 % dye rejection. • TFC membranes deliver stable precise screening ability in both polar and non-polar solvent. [ABSTRACT FROM AUTHOR]

As the key of organic solvent nanofiltration (OSN) technology, OSN membranes could effectively retain small molecules with molecular weight between 200 and 1000 Dalton (Da), but they still face some problems such as low solvent permeance. In this work, we fabricated a poly(amide-ester) selective layer on polyimide substrate surface by introducing β-cyclodextrin (β-CD) into the aqueous phase solution to assist the interfacial polymerization reaction between m -phenylenediamine (MPD) and trimesoyl chloride (TMC), followed by cross-linking and solvent activation treatment. Thus, we successfully fabricated a kind of thin film composite (TFC) membrane with high selective permeability for OSN. We emphasized that extra-low contents were employed for both MPD and β-CD, which were 0.05 wt% and 50 mg L−1, respectively. The effect of β-CD content on the pore size, surface shape, surface hydrophilicity, surface chemistry, filtration performance, as well as durability performance of the OSN membrane was studied in depth. β-CD endows the selective layer with better hydrophilicity and larger pore size. The optimized OSN membrane possesses a Rhodamine B (RDB, 479 Da) rejection of 99.2 % and an ethanol permeance of 70.6 L m−2 h−1 MPa−1. Furthermore, the optimized OSN membrane remains above 99 % RDB rejection after being immersed in DMF at 25 °C for 1000 h, which demonstrates its superb solvent resistance. Additionally, the optimized OSN membrane exhibits outstanding long-time performance and possesses a rejection of 98 % for Jacobsen catalyst during more than 106 h semi-continuous filtration using Jacobsen catalyst/ethyl acetate solution as feed, indicating its vast potential in the recovery of catalyst. [Display omitted] • Highly permeable OSN membrane was fabricated via β-cyclodextrin assisted interfacial polymerization • β-cyclodextrin endows the OSN membrane with better hydrophilicity and larger pore size • The optimized OSN membrane shows an ultra-smooth surface with a roughness of 5.0 ± 0.1 nm • The optimized OSN membrane achieves an ethanol permeance of 70.6 L m−2 h−1 MPa−1 and a Rhodamine B rejection of 99.2 % • The optimized OSN membrane shows excellent recovery efficiency for the Jacobson catalyst [ABSTRACT FROM AUTHOR]

Abstract In this work, a novel thin-film composite membrane composed of a polyester film on a cellulose support was successfully synthesised. The polyester film was formed from the interfacial reaction between catechin, a bio-derived poly-phenol, and terephthaloyl chloride (TPC). The cellulose support was prepared by non-solvent induced phase separation from a 12.5 wt% cellulose dope solution in 1-ethyl-3-methylimidazolium acetate ionic liquid. The composite membrane was characterised by Fourier Transform Infrared and X-Ray Photoelectron Spectroscopy to confirm the success of the interfacial reaction. Scanning electron and atomic force microscopy were used to study the surface morphology and roughness of the membranes produced. The performance of the composite membranes in terms of solvent permeance and solute rejection was investigated by studying the rejection of a broad range of different molecular weight dyes in dimethylformamide (DMF) solution. The membranes showed an average DMF permeance of 1.2 L m−2 h−1 bar−1 with a molecular weight cut-off of around 500 g mol−1. The membrane was stable in DMF over 30 days with no significant change in performance. The membrane has potential application in the food and pharmaceutical industries. Highlights • A catechin/cellulose composite nanofiltration membrane has been developed. • The membrane made from bio-derived materials is stable in dimethylformamide. • The cross-linked catechin selective layer exhibits high DMF fluxes. • The membrane rejects molecules with a molecular weight higher 500 g mol−1. [ABSTRACT FROM AUTHOR]

By direct introducing ionic liquid into the interfacial polymerization process of β-CD, the porous monomer based thin-film composite membranes are fabricated for efficient organic solvent nanofiltration with a high ethanol permeance of 57.01 L·m−2·h−1·MPa−1 and an ideal dye rejection rate of 99.98 %. [Display omitted] • IL assists the interfacial polymerization of porous monomers into membranes. • The TFC membranes exhibit high ethanol permeance and ideal dye rejection. • The effects of IL on the membrane structure and separation property are studied. β-cyclodextrin (β-CD), with intrinsic nano-cavity, is a promising monomer to construct thin-film composite (TFC) membranes for molecular separations. Nevertheless, interfacially polymerize β-CD into continuous membranes is challenging due to the low reactivity of hydroxyl groups. To address this issue, in this work, ionic liquid (IL) has been introduced into the interfacial polymerization (IP) process of β-CD and trimesoyl chloride (TMC), forming high-quality TFC membranes for organic solvent nanofiltration (OSN). Investigations have been done into how IL effects membrane structure and separation performance. In contrast to traditional β-CD-TMC TFC membrane, the β-CD-IL-TMC TFC membrane possesses upgraded crosslinking, continuity, stability, and OSN separation property. The best β-CD-IL-TMC membrane has an ethanol permeance of up to 57.01 L m−2h−1 MPa−1 and Naphthol green B rejection rate of 99.98% and can sustain a stable separation performance within 20-hour test, indicating the fabricated β-CD-IL-TMC membranes have advantage of separating and purifying organic solvent. [ABSTRACT FROM AUTHOR]

Membrane-based filtration offers many benefits like lower energy consumption and operating cost for separation in harsh solvents. In particular, such membranes need to have high nanofiltration separation efficiency and high resistance to organic solvents. Unfortunately, the common thin film composite (TFC) - based organic solvent nanofiltration membranes often give low solvent permeance due to the dense skin layer atop the substrate. To address this, we fabricated a covalent organic framework (COF) - incorporated TFC membrane through the in-situ formation of benzene-1,3,5-tricarboxaldehyde (TFB) and graphene oxide (GO) in p -Cymene, a less toxic solvent, with p -Phenylenediamine (PPD) in aqueous phase via interfacial polymerization. The PES-COF-GO membranes exhibited optimal solvent permeance and separation efficiency at an intermediate 0.8wt% GO, which gave the highest water permeance of 16.2L/m2 h bar and a molecular weight cut-off (MWCO) of around 325 gmol-1. In addition, the crosslinked GO-COF layer endowed the membrane with chemical stability in non-polar solvents. The mechanical strength of PES-COF-GO membrane was also improved due to the COF-GO layer atop the PES substrate making the surface tighter and mechanically stronger. [Display omitted] • COF-incorporated TFC membrane fabricated via IP in p -Cymene, a less toxic solvent. • Higher GO loading of 1.2% gave lower water permeance due to GO agglomeration. • PES-COF-0.8%GO gave best water permeance of 16.2 L/m2 h bar and MWCO of 325 gmol-1 • Mechanical strength of the TFC membrane enhanced by COF-GO layer on PES substrate. • Crosslinked GO-COF network conferred membrane with good organic solvent stability. [ABSTRACT FROM AUTHOR]

High-performance organic solvent nanofiltration (OSN) membranes play an indispensable role in chemical separation processes. However, conventional OSN membranes such as thin-film composite polyamide (TFC-PA) membranes exhibit insufficient perm-selectivity. In this study, we developed a high-performance TFC- PA OSN membrane on a porous polyketone (PK) support by regulating interfacial polymerization (IP) with acetone as an organic co-solvent. The effect of the acetone co-solvent on the IP reaction and PA nanofilm morphology was investigated. Acetone serves as a regulator to mediate the IP reaction by facilitating the convective diffusion of monomers at the aqueous/organic interface. Furthermore, experimental results and molecular dynamics (MD) simulation analysis confirmed that the addition of acetone increases the width of the IP reaction zone, facilitates more violent exothermic reactions, and induces aggravated vaporization of acetone, resulting in the formation of a 3D honeycomb-like structure with an ultrahigh specific surface area. Compared with the TFC-PA membrane prepared by the conventional IP method, the TFC-PA-acetone membrane prepared by acetone-regulated IP (ARIP) exhibited 2.6 times higher methanol solvent permeance (7.0 LMH/bar) and comparable methyl orange rejection (94.6%). This work explores the underlying mechanism of acetone-regulated IP, providing a facile strategy for tailoring the membrane morphology with high-efficiency organic solvent nanofiltration. [Display omitted] • Acetone-regulated interfacial polymerization (ARIP) was first used to prepare OSN PA membranes. • Acetone enlarged the IP reaction zone and greatly promoted the convective diffusion of MPD and TMC. • TFC-PA-acetone membrane shows a 3D honeycomb-like structure with an ultrahigh specific surface area • TFC-PA-acetone membrane exhibits 2-3 times increase in permeance and long-term stability. [ABSTRACT FROM AUTHOR]

Preparation of defect-free and optimized thin film nanocomposite (TFN) membranes is an effective way to enhance the process of organic solvent nanofiltration. However, it still remains a great challenge due to poor filler particle dispersibility in organic phase and compatible issue between fillers and polymers. Aiming at these difficulties, UiO-66-NH2 nanoparticles were surface modified with long alkyl chains and used in the preparation of TFN membranes. As a result, defect-free TFN membranes with ultrathin MOF@polyamide layer were successfully prepared benefited from the improved particle dispersibility in n-hexane. Significant enhancement was found in methanol permeance after nanoparticle incorporation, without comprising the tetracycline rejection evidently. Especially, the novel TFN membrane prepared with organic phase solution containing 0.15% (w/v) modified UiO-66-NH2 nanoparticles showed a superior methanol permeance of 20 L·m−2·h−1·bar−1 and a tetracycline rejection of about 99%, which is appealing to the application in pharmaceutical industry for example. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1303-1312, 2017 [ABSTRACT FROM AUTHOR]

In this contribution, thin-film nanocomposite membranes with an interlayer (TFNi) were fabricated on poly (m-phenylene isophthalamide) (PMIA) substrates for organic solvent nanofiltration (OSN). The selective layer was formed by interfacial polymerization between 1,3,5-benzenetricarbonyl trichloride in the ionic liquid phase and mixed amine monomers in the aqueous phase. Five types of interlayer materials were prepared via a facile mixing method. After systematical characterizations, it was found that interlayer materials could not only adjust the surface morphology, porosity, and hydrophilicity of the substrate but also promote the controlled growth of thin and defect-free polyamide (PA) layer via the subsequent interfacial polymerization process. We also analyzed the radar chart representation of the various characteristic values of the membrane physiochemical properties (thickness, crosslinking degree, roughness, and hydrophilicity) and membrane separation performance (permeance, and rejection), in order to elucidate their relationships. Among the five TFNi membranes, PMIA/Co-PIP/PA membrane showed high ethanol permeance (2.93 L m−2 h−1 bar−1), high rejection (∼95%) of organic solutes with molecular weights above 697 Da, and robust long-term stability during separating erythromycin/methanol mixtures (50 h). The designed TFNi membranes were superior to the traditional PMIA/PA membrane, and the permeance of which was only 0.7 L m−2 h−1 bar−1. In addition, compared with the traditional PMIA/PA, the introduction of Co-PIP nanomaterials as an interlayer enhanced the tensile strength at break (12 vs. 19 MPa) and elongation of the PMIA/Co-PIP/PA membrane (32.0% vs. 83.9%). Accordingly, the designed PMIA/Co-PIP/PA membrane has great potential in industrial separation applications for drug concentration and organic solvent recovery. [Display omitted] • Nanomaterial interlayers were used to fabricate thin-film nanocomposite membranes. • Permeance of TFNi membranes was remarkably increased without sacrificing rejection. • The introduction of interlayers enhanced the mechanical property of the membranes. • Membrane physiochemical properties greatly affect the OSN separation performance. • Mixed amines were used as aqueous monomers for the interfacial polymerization. [ABSTRACT FROM AUTHOR]

Interfacial polymerization has always been a research hotspot for the preparation of polyamide (PA) membranes for molecular sieving. In previous reports, water-soluble amines (such as piperazine (PIP), m-phenylenediamine (MPD), etc.) were mostly used as monomers containing amino functional groups in the aqueous phase to conduct interfacial polymerization with 1,3,5-mesotribenzoyl chloride (TMC) in hexane, resulting in a dense PA film. However, this approach limits the diversity of polymer structures in PA films. To introduce water-insoluble 9,9-Bis(4-aminophenyl)fluorene (BAF) with a rigid twisted structure into interfacial polymerization, this study reports the interfacial polymerization of BAF in DMF/water solution with TMC in n-hexane. BAF-PA films with a larger free volume compared with MPD-PA were successfully prepared. The anomalous interfacial diffusion phenomenon was explained by the interfacial properties and molecular diffusion mechanism of the two-phase solvent and was confirmed by observing the microscopic morphology of the film. Since the structure of BAF-PA has a larger free volume, the BAF-PA film prepared by co-solvent interfacial polymerization has higher permeance to methanol (23.88 L m−2 h−1 bar−1). Meanwhile, it has more than 90% rejection of dyes with molecular weights of 585 Da and above. The large free volume PA film prepared with DMF/water mixed solvent exhibited excellent performance in organic solvent nanofiltration. This method also offers the possibility of introducing other water-insoluble amines into the interfacial polymerization to prepare PA films. [Display omitted] • Polyamide membranes with rigid twisted structures for nanofiltration of organic solvents. • Interfacial polymerization using DMF as solvent and water as co-solvent. • High solvent permeance and excellent dye separation performance. • Interfacial polymerization with water-insoluble amines. [ABSTRACT FROM AUTHOR]

• The nanofilm with high microporosity was prepared from a novel Tris-Phenol monomer. • Surfactant DTAC addition improved the selectivity of the Tris-Phenol OSN membrane. • The MWCO of Tris-Phenol membrane was as low as 295 Da in solvent methanol. • It showed not only size selective mechanisum but also a charge selective behavior. As an emerging membrane separation technology, organic solvent nanofiltration (OSN) has shown great application potential in the field of pharmaceutical and chemical industries referring to organic media. Herein, we prepared a novel microporous thin-film composite (TFC) OSN membrane with superior perm-selective performances, which was fabricated by applying 4,4′,4″-trihydroxytriphenylmethane (Tris-Phenol) to react with trimesoyl chloride (TMC) by interfacial polymerization (IP) technique. The rigid, non-planar and multifunctional nature of Tris-Phenol endowed the polyarylate nanofilm with enhanced microporosity. Of note, the prepared composite membrane showed good selectivity to small organic solutes with molecular weight cut-off (MWCO) as low as ∼295 Da, meanwhile had medium methanol permeance up to 5.86 LMH/bar, by the help of surfactant dodecyl trimethyl ammonium chloridea (DTAC) during the IP reaction. The experiments showed that the Tris-Phenol membrane exhibited extraordinary long-term operation stability. In addition, the Tris-Phenol membrane could achieve separation of solutes with similar molecular weights but different charges. This research well illustrated the novel IP monomer design strategy to fabricate new TFC OSN membrane with high perm-selectivity. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is a green, environmentally friendly and sustainable separation technology. High-performance OSN membranes are expected to play a critical role in the field of chemical separation involving organic solvents. However, traditional OSN membranes suffer from the constraints on perm-selectivity. Herein, we introduced macrocyclic molecules with intrinsic angstrom-size cavity, pillar[n]arene (P[n]a, n = 5, 6), as a novel aqueous monomer to react with trimesoyl chloride (TMC) to prepare highly perm-selective thin-film composite (TFC) OSN membranes through interfacial polymerization. The prepared TFC-P[n]a membranes exhibit ultra-thin selective layer thickness of sub-10 nm and possess permanent intrinsic microporous structure, which endows the membrane with high perm-selectivity. Especially, the TFC-P[6]a membrane exhibits a high methanol permeance (8.10 L m−2 h−1 bar−1) and a low molecular weight cut-off (MWCO) of 300 g mol−1. In addition, the prepared TFC-P[n]a membranes exhibit molecule sieving function and could discriminate molecules with similar molecular weights but different shapes. Our work provides an insight of material design for the preparation of next-generation high-performance organic solvent nanofiltration membranes. [Display omitted] • The OSN membranes were prepared via IP of macrocyclic molecules pillar[n]arene with trimesoyl chloride. • The molecular cavity of pillar[n]arene and its 3D structure provide extra channels for transportation of solvent molecules. • The TFC-P[n]a nanofilms have ultra-thin thickness of sub-10 nm. • The MWCO of the TFC-P[n]a composite membranes were as low as ≤ 300 g mol−1. [ABSTRACT FROM AUTHOR]

In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement. The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20 L/m 2 h at 5 bar with a molecular weight cut off (MWCO) of around 1000 g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The development of high flux and solvent-stable thin-film composite (TFC) organic solvent nanofiltration (OSN) membranes was reported. A novel cross-linked polyimide substrate, consisting of a thin skin layer with minimum solvent transport resistance and a sponge-like sublayer structure that could withstand membrane compaction under high-pressure was first fabricated. Then the solvent flux was significantly enhanced without compromising the solute rejection by the coupling effects of (1) the addition of triethylamine/camphorsulfonic acid into the monomer solution, and (2) the combined post-treatments of glycerol/sodium dodecyl sulphate immersion and dimethyl sulfoxide (DMSO) filtration. Finally, the long-term stability of the TFC membrane in aprotic solvents such as DMSO was improved by post-crosslink thermal annealing. The novel TFC OSN membrane developed was found to have superior rejection to tetracycline (MW: 444 g/mol) but was very permeable to alcohols such as methanol (5.12 lm−2h−1bar−1) and aprotic solvents such as dimethylformamide (3.92 lm−2h−1bar−1) and DMSO (3.34 lm−2h−1bar−1). © 2014 American Institute of Chemical Engineers AIChE J, 60: 3623-3633, 2014 [ABSTRACT FROM AUTHOR]

Separation performance of polyamide composite membranes is affected by several parameters during formation of thin upper layer via interfacial polymerization. We investigated the effect of various polyamide synthesis conditions on the performance of organic solvent resistant polyamide composite membranes through the model equations designed by 2-level fractional factorial design. The dewaxing solvent recovery was selected as separation process. Five factors were changed in two level includin; TMC concentration (0.05-0.1%), MPD concentration (1-2%), support immersion time in organic solution (2-4 min), support immersion time in aqueous solution (1-2 min), and curing temperature (70-80 °C). The resultant equations showed 93.48% and 94.82% of the variability (R) in data used to fit oil rejection and permeate flux models, respectively. The analysis of variance revealed that both models were high significant. It was also observed that TMC concentration, MPD concentration and immersion time in TMC have more pronounced effect on the oil rejection and permeate flux than other factors and interactions. Optimal polyamide preparation conditions were obtained using multiple response method for 94% oil rejection as target value. According to the results, the best value of permeate flux (8.86 l/(m·h)) was found at TMC concentration of 0.1%, MPD concentration of 1.94%, immersion time in TMC of 3.88 min, immersion time in MPD of 1.95 min and curing temperature of 71.96 °C with desirability factor of 1. [ABSTRACT FROM AUTHOR]

Interfacial polymerization (IP) is a rapid and convenient approach to fabricating thin-film composite (TFC) membranes with high permeance and satisfactory rejection for organic solvent nanofiltration (OSN). However, it is normally difficult to directly conduct the IP approach on the commercial membrane substrate (particularly, in the microfiltration range) because the monomers on the substrate are unevenly distributed during the IP reaction. In the current work, Cu-TCPP nanosheets were in-situ grown on commercial PVDF microfiltration substrate (pore size of 0.45 μm) by using preinstalled Cu 2 O nanoparticles as a copper ion source. The Cu-TCPP nanosheets covered the large pores and penetrated the surface layer of the PVDF substrate. The obtained PVDF/ i -Cu-TCPP was then used as a substrate to conduct the IP and to fabricate the PVDF/ i -Cu-TCPP/PA membrane. It was found that i -Cu-TCPP which serves as an interlayer could store the aqueous solution of the amine and was critical to the formation of a thin and defect-free polyamide separation layer. In comparison, loading of the Cu-TCPP on the PVDF substrate by filtration led to the formation of PVDF/ e -Cu-TCPP/PA, which however exhibited inferior separation performance as compared to the PVDF/ i -Cu-TCPP/PA membrane. More importantly, the PVDF/ i -Cu-TCPP/PA membrane exhibited higher tensile strength (6.0 vs. 2.8 MPa) compared to the PVDF/ e -Cu-TCPP/PA membrane, due to the enhanced interaction (adhesion) between the PVDF substrate and the i -Cu-TCPP interlayer. Under optimal synthetic conditions, the permeance of the PVDF/ i -Cu-TCPP/PA membrane was almost 4 times that of the PVDF/PA membrane (1.93 vs. 0.49 L m-2 h-1 bar-1) without compromising rejection (>96%). The optimal TFC membrane also showed excellent OSN performance towards various organic solvents and good long-term stability to VB12/ethanol mixtures (50 h). Furthermore, the concentration test of erythromycin in methanol solution indicated that the PVDF/ i -Cu-TCPP/PA membrane has great potential in the pharmaceutical industry for drug concentration and organic solvent recovery. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultra-low concentration for both MPD and TMC used during the interfacial polymerization process. • Ultra-low content Tannic acid functionalized MoS 2 nanosheets regulate the interfacial polymerization process. • Ultra-thin, ultra-smooth (2 nm in roughness) and hydrophilic TFN OSN membrane was obtained. • The TFN OSN membrane achieves a much higher pure DMF permeance of 219 L m−2h−1 MPa−1. • The TFN OSN membrane tolerates DMF at 80 ℃ for greater than 144 h and remains greater than 98% RDB (479 Da) rejection. Organic solvent nanofiltration (OSN) membranes are the key factors for the treatment of organic solution via OSN technology. In this work, we fabricated a kind of ultra-thin and ultra-smooth thin-film nanocomposite (TFN) OSN membrane using interfacial polymerization (IP) process with ultra-low concentration for both the aqueous and the organic monomers, together with doped tannic acid (TA) functionalized Molybdenum disulfide (MoS 2) nanosheets of ultra-low content in the aqueous monomer solution, and followed by post-IP chemical crosslinking and solvent activation procedures. The results demonstrated that the incorporated TA-MoS 2 nanosheets not only help to promote the solvent permeation, but also help to increase the solvent resistance and fouling resistance of the fabricated membrane. The optimal TFN OSN membrane fabricated using 0.05 wt% aqueous m -phenylenediamine (MPD) solution doped with TA-MoS 2 nanosheets content of 50 mg L−1 and 0.0025 wt% trimesoyl chloride (TMC) / n -hexane solution has an ultra-thin barrier layer, with an average thickness of about 15 nm. This endows it a much higher pure DMF permeance of 219.1 L m−2 h−1 MPa−1, which is much superior over most of literature works. Meanwhile, the fabricated TFN OSN membrane achieves a rejection of 99.1 % for rhodamine B (RDB, 479 Dalton), which is about 10.1 % increment compared with that of the baseline thin-film composite (TFC) membrane. The TFN OSN membrane also features an ultra-smooth skin layer, with a surface roughness of merely about 2.0 nm, which is quite beneficial for its fouling resistance performance. Moreover, the TFN OSN membrane features outstanding high solvent resistance. It remained a nearly constant and extremely high rejection for Rose Begal (RB, 1017 Dalton), about 99.9 %, and a much higher DMF permeance, 101 ± 2 L m−2 h−1 MPa−1, after cross-flow filtration for more than 200 h using 100 mg L−1 RB / DMF solution as feed, which is seldomly reported in literature. Even being immersed in DMF at 80 °C for more than 144 h, it remained a rejection of higher than 98 % for Rhodamine B (479 Dalton), indicating its superior solvent resistance and promising industrial application prospect. [ABSTRACT FROM AUTHOR]

• A state-of-the-art PE membrane was fabricated using the extraction of the PS-SEBS phase from the as-fabricated PS/SEBS/PE composite by using a solvent • A TFC membrane was prepared via the fabrication of the thin film PA layer on the PE membrane covered with MnO 2 / Fe (III)-tannic acid interlayer • The TFC membranes were fabricated with a uniform PA layer • A significant dye rejection performance and superior solvent resistance was shown via the fabricated TFC membranes It is of great importance to select an ultrafiltration (UF) support with outstanding solvent stability to fabricate thin film composite (TFC) organic solvent nanofiltration (OSN) membranes. High density polyethylene (HDPE)-polystyrene (PS)-styrene-ethylene-butylene-styrene (SEBS) blends were prepared through the incorporation of different SEBS weight percentages. Next, HDPE membranes were made via extracting the dispersed phase from the HDPE/PS/SEBS blends using THF. Then, the membrane with the optimum properties was selected as the support for preparing the TFC membranes. Accordingly, the support was first contacted with KMnO 4 solution, by which MnO 2 nanoparticles (NPs) were generated on the support surface. The membrane surface was then contacted with tannic acid (TA) and FeCl 3 aqueous solutions consecutively to form a uniform TA-Fe3+ layer. Eventually, the PA layer was formed on the membrane surface through contacting with m-phenylenediamine aqueous solution and trimesoyl chloride/n-hexane solution consecutively. The TFC membrane exhibited extraordinary dyes rejection and good methanol permeance in OSN applications. Moreover, DMF activation process was conducted on the TFC membrane, after which both the dye rejection performance and methanol permeance were enhanced. Moreover, it is worth pointing out that the membrane provided an excellent solvent stability after dipping in DMF after 100 days. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel n-TFC membrane was developed by IP method on PEI/modified SiO2 support. [•] The amino-functionalized silica was blended with PEI to prepare solvent resistant support. [•] Effect of modified nanosilica on chemical and physical stability of support was studied. [•] Support morphology influenced the performance of resultant n-TFC membrane. [•] n-TFC membrane has proper lube oil rejection even at high pressure for OSN process. [ABSTRACT FROM AUTHOR]

Covalent organic polymers (COPs) are prepared via the non-uniform covalent assembly of organic building blocks, endowing their structures with permanent pores, thereby rendering them suitable for diverse applications. The use of COPs in the fabrication of composite membranes can enhance their permeability, selectivity, and chemical stability. However, the existing COP synthesis processes are typically tedious, thus necessitating the development of rapid and simpler routes. We demonstrate an easily performed synthesis route for the rapid (less than 10 s) fabrication of COP-based composite membranes via interfacial polymerization. The membranes were directly prepared on a polyacrylonitrile substrate without transferring the COP layer onto a porous support. The hydrophobicity of the membranes was achieved by the integration of fluorine-rich groups along the polymer backbone. The obtained solvent-resistant composite membranes exhibited a toluene permeance of 11 L m−2 h−1 bar−1 and congo red (687 g mol−1) rejection levels of more than 95%. The remarkable performance, crosslinked polymer structure, and manufacturing scalability of the fabricated thin films make them attractive as solvent-resistant nanofiltration membranes. Ultrafast fabrication of covalent organic polymer composite membranes for high-permeance nanofiltration in toluene. [Display omitted] • Rapid synthesis of covalent organic polymer (COP) membrane via interfacial polymerization • Hydrophobicity of COP by integrating fluorine atoms • Hydrophobic pathways for highly selective organic solvent permeance • COP membranes with excellent toluene permeance and high dye rejections • Solvent-stable COP thin films with long-term stability during organic solvent nanofiltration [ABSTRACT FROM AUTHOR]

In this work, sandwich-like polyamide (PA) organic solvent nanofiltration (OSN) composite membranes were prepared upon hydrolyzed polyacrylonitrile (HPAN) substrates having interlayers of networked polydopamine (PDA), chained polyaniline (PANI) and porous covalent organic frameworks (COFs). The PA selective layer generated by interfacial polymerization (IP) of 1,3,5-benzenetricarbonyl trichloride (TMC) and polyethyleneimine (PEI). The surface morphology and hydrophilicity of HPAN substrate, and subsequent IP process was successfully regulated by these interlayers. Radar chart representation of the characteristic values of Interlayer/HPAN substrate, PA layer and PA/Interlayer/HPAN OSN membrane was described and analyzed. Compared with the low permeance of PA/PDA/HPAN OSN membrane, PA/PANI/HPAN OSN membrane displayed quite high ethanol permeance (3.1 L∙m−2 h−1 bar-1) and acetone permeance (12.4 L∙m−2 h−1 bar-1), owing to its thinner and rougher PA selective layer. Furthermore, PA/TpTD/HPAN OSN membranes had superior separation performance with 99.0% of rejections to dyes having molecular weights above 350.4 Da, and 95.0% of rejections to crude drugs and natural pigments. Moreover, PA/Interlayer/HPAN OSN composite membranes maintained excellent anti-fouling performance, long-term stability and chemical resistance under strong acidic solution. Therefore, the polymeric interlayers with different structures could manipulate the IP process and provide new insight for preparing of PA based OSN composite membranes with excellent-performance and structural-stability. [Display omitted] • Interlayer-modulated PA composite membrane prepared by interfacial polymerization. • PA/Interlayer/HPAN OSN composite membranes showing superior permeance and rejection. • PA/Interlayer/HPAN composite membranes showed satisfying structural stability. [ABSTRACT FROM AUTHOR]

• A hyper-cross-linked polyamine thin film composite organic solvent nanofiltration (PA@PS/PET) membrane was fabricated. • Cyanuric chloride was used as cross-linker in interfacial polymerization. • The highest flux was found to be 30 L m−2h−1 at 8 bar for methanol. • The PA@PS/PET showed rejection of congo red reaching to a value of >99%. • The membrane showed stability under the operating harsh conditions. Thin film composite nanofiltration (TFC-NF) membranes have been developed for organic solvent nanofiltration. Most of the polyamide TFC-NF membranes are vulnerable to nucleophilic hydrolysis. A multifucntional amine was crosslinked with a trifucntional non-aqueous monomer namely cyanuric chloride (CC) on surface of self-fabricated polysulfone/polyester terephthalate (PS/PET) membarne support leading to a new polyamine active layer containing TFC-NF membrane named as PA@PS/PET. The fabricated PA@PS/PET membrane was thoroughly characterized by several characterization techniques such as ATR-FTIR, XPS, FE-SEM, Water Contact Angle (WCA), and EDX analysis. PA@PS/PET TFC-NF membrane showed remakable perfomance in terms of solvent flux for all tested solvents including water, methanol, ethanol and isopropanol. The highest flux was found to be 29.58 L m−2h−1 at 8 bar for methanol. The flux of solvents was found to be inversly related to the viscosity of the solvents. The PA@PS/PET membrane showed remarkably high rejection of solute (Congo Red) reaching to a value of ∼98%. Moreover, the PA@PS/PET membrane showed permanant flux of 8.45 L m−2 h−1 at 2 bar during solute separation (CR dye rejection) tests which hinted the stability of the membrane under the applied operating conditions. [Display omitted] [ABSTRACT FROM AUTHOR]