Membranes For Oil-water Separation Research Articles

Durable underwater super-oleophobic/super-hydrophilic conductive polymer membrane for oil-water separation.

Oily sewage has made serious impact on environment and people's life, and its treatment has become a global problem to be urgently solved. Oil-water separation has been considered to be an effective method to treat oily sewage at present. In this work, an underwater super-oleophobic/super-hydrophilic membrane with oil-water separation and self-cleaning properties was fabricated by electrochemical oxidation of sodium lignosulfonate doped polypyrrole. The membrane showed super-hydrophilicity for water-removal in air and super-hydrophilicity for oil-removal underwater in both oxidation and reduction states. The oil-water separation efficiency of the membranes for different organics exceeded 98.44%, no matter in oxidation or reduction state. Moreover, the membrane still exhibited excellent performance in terms of the oil-water separation efficiency and flux after 70 cycles, which were greater than 97.18% and 70.14 L·m-2·h-1, respectively. Simultaneously, through exploration of the mechanism, it was found that the larger anion kept intact in the membrane during the redox process, which made the stability of composition and performance. Thus, the membrane with advantageous properties, including underwater super-oleophobic/super-hydrophilicity, high oil-water separation efficiency, high circulating rate and stability, has significant potential in separation and collection of oily sewage.

In situ reaction enabled surface segregation toward dual-heterogeneous antifouling membranes for oil-water separation

Fabricating membranes with superior antifouling property and long-term high performance is in great demand for efficient oil-water separation. Herein, we reported a reaction enabled surface segregation method for antifouling membrane fabrication, in which the pre-synthesized fluorinated ternary copolymer Pluronic F127 was coordinated with Ti4+ as segregation additive in the membrane casting bath. Additionally, tannic acid was utilized to enhance the self-assembly of the copolymer in the coagulation bath, and freshly-biomineralized TiO2 was anchored into the membrane surface through hydrogen bond. A hydrogel layer was constructed onto the membrane surface with synergistically tailored heterogeneous chemical composition and heterogeneous geometrical roughness. The dual-heterogeneous membrane exhibited hydrophilic and underwater superoleophobic features, resulting in high water flux (621.7 L m−2 h−1) at low operation pressure of 0.05 MPa and an excellent antifouling property (only 4.8% flux decline during 24-hour filtration). In situ reaction enabled surface segregation method will accelerate the development of antifouling membranes for oil-in-water emulsion separation.

Double network cross-linked hydrogel coating membrane with photocatalytic self-cleaning performance for efficient oil-water separation

Oil-water separation is one of the most attractive areas in the field of energy and the environment. However, the synthesis of oil-water separation membranes with high separation efficiency and anti-fouling via simple methods is still a challenge. In this work, a double network with tannic acid and g-C3N4 cross-linked gelatin hydrogel coating membrane was prepared via ultrasound and coating. The prepared hydrogel had excellent mechanical properties and swelling resistance and also endowed the membrane with underwater superoleophobicity. For stratified oil-water mixtures, the separation flux achieved 40,355 ± 1957 L·m−2·h−1 and separation efficiency higher than 99 %. Moreover, after 40 cycles, there was no decrease significantly in separation performance. For oil-in-water emulsions, the separation efficiency is >99.90 % under gravity. The adsorption of MB by the GE-CNTA-PP membrane conformed to a pseudo-first-order kinetic process (R2 = 0.99906), which was consistent with the Langmuir isothermal adsorption model (R2 = 0.99932). The contaminated membrane could self-clean via photocatalytic reaction, which mechanism was explained through theoretical investigation of the band structure of g-C3N4 by DFT. Due to these obvious advantages, the practical application of the gelatin-based hydrogel membrane in the purification of oily wastewater is promising.

Preparation and characterization of electrospun PVDF/PVP/SiO2 nanofiber membrane for oil-water separation

For oily wastewater purification, polyvinylidene fluoride (PVDF) nanofiber membranes have been widely noticed for their excellent mechanical strength and corrosion resistance. However, it is prone to serious oil fouling problems during use, resulting in reduced flux and inability to be used repeatedly. It has become a hot research topic to develop simple methods to realize its hydrophilic modification for oily wastewater treatment to address this problem. Herein, a novel separation membrane was prepared by doping polyvinylpyrrolidone (PVP) and hydrophilic silica nanoparticles (SiO2 NPs) into PVDF using a facile one-step electrospinning method. The modified membrane shows hydrophilicity, water contact angle (WCA) is 0°, oleophobicity in water, and oil contact angle (OCA) is more than 145° and has good separation efficiency and flux for both oil-water mixtures and emulsions. After 30 times of mixture and emulsion separation tests, the separation efficiency is above 99.5 % and 97 %, respectively, showing good separation and reusability. Besides, compared with hydrophilic modification methods such as surface coating and grafting, the proposed modification method is simpler and has great potential in treating oily wastewater.

Urchin-like fluorinated covalent organic frameworks decorated fabric for effective self-cleaning and versatile oil/water separation

Oil contamination and industrial organic pollutants emission have been a serious problem affecting the ecological and residential environment. Membrane-based separation shows great application prospect due to its low-cost, environmental-friendly and easy operation. Therefore, the development of efficient oil-water separation membranes is highly desirable. Herein, a fabric filter with superwettability was prepared by coating urchin-like fluorinated covalent organic frameworks (COFs) on fabric, which was well utilized in filtering immiscible oil-water mixture and surfactant-stabilized water-in-oil emulsion driven only by gravity for the first time. The as-prepared COF fabric filter (defined as fabric@u-FCOF) possessed many outstanding properties, including superhydrophobicity with the water contact angle of approximately 151.6°, satisfactory resistance for alkaline, acidic and saline environments, as well as superior mechanical durability under harsh conditions. Because of the super-micropore of fabric@u-FCOF and the nanopore in the COF coating, the obtained fabric@u-FCOF exhibited excellent performances in terms of separation efficiency and permeability, in which the oil flux was up to 16964 L·m−1·h−2 and separation efficiency for the mixed o-dichlorobenzene/water was higher than 99.4%. In addition, the fabric@u-FCOF also showed excellent self-cleaning performance due to the micro/nano hierarchical structure of its surface. These excellent properties make it an ideal candidate for applications of oil/water separation and water purification.

Fabrication and characterization of superhydrophilic graphene-based electrospun membranes for efficient oil-water separation

This research article investigates the fabrication of superhydrophilic graphene-based electrospun membranes for efficient oil-water separation. The study utilizes cellulose acetate (CA) as the base material for membrane fabrication, employing an electrospinning technique followed by the electrohydrodynamic atomization of graphene oxide (GO) to enhance their hydrophilicity. The surface morphology, water contact angle, and Fourier Transform Infrared (FTIR) spectra of the fabricated membranes were analyzed to assess their properties. The membrane characterization techniques revealed the successful integration of GO nanosheets on the surface of the highly porous interconnected nanofibrous matrix. The modified membranes exhibited superhydrophilicity and underwater oleophobicity. The water contact angle of the optimized GO-based electrospun CA membrane was reduced from 110° to zero within 3 s. The performance of the membranes was evaluated through oil-water separation experiments using different types of oils (such as toluene, n-decane, and hexane) in water. The results demonstrated that the graphene-based optimized membranes exhibited high separation efficiency (3820 LMH), with a water permeation flux as high as 65.5 % compared to CA membranes (2308 LMH). The efficiency of separation while using all three different oils with DI water was calculated to be >99.9 %. The study provides valuable insights into the use of graphene-based membranes for oil-water separation and highlights the potential of the electrohydrodynamic atomization technique for the surface modification of membranes. The developed membranes have great potential applications in various industries, including oil and gas, chemical, and wastewater treatment.

Recent Developments in Two-Dimensional Materials-Based Membranes for Oil-Water Separation.

The industrialization witnessed in the last century has resulted in an unprecedented increase in water pollution. In particular, the water pollution induced by oil contaminants from oil spill accidents, as well as discharges from pharmaceutical, oil/gas, and metal processing industries, have raised concerns due to their potential to pose irreversible threats to the ecosystems. Therefore, the effective treating of these large volumes of oily wastewater is an inevitable challenge to address. Separating oil-water mixtures by membranes has been an attractive technology due to the high oil removal efficiency and low energy consumption. However, conventional oil-water separation membranes may not meet the complex requirements for the sustainable treatment of wastewater due to their relatively shorter life cycle, lower chemical and thermal stability, and permeability/selectivity trade-off. Recent advancements in two-dimensional (2D) materials have provided opportunities to address these challenges. In this article, we provide a brief review of the most recent advancements in oil-water separation membranes modified with 2D materials, with a focus on MXenes, graphenes, metal-organic frameworks, and covalent organic frameworks. The review briefly covers the backgrounds, concepts, fabrication methods, and the most recent representative studies. Finally, the review concludes by describing the challenges and future research directions.

Metal–Organic Frameworks-Based Membranes with Special Wettability for Oil–Water Separation: A Review

The presence of oily wastewater poses a significant threat to both the ecological environment and public health. In order to solve this problem, the design and preparation of an efficient oil–water separation membrane is very important. Metal–organic frameworks (MOFs) are currently a promising material for oil–water separation due to their tunable wettability, adjustable pore size and also low density, high porosity, and high surface area. Therefore, MOFs-based membranes show great potential in the field of oil–water separation. In this paper, we first introduce the oil–water separation mechanism and then comprehensively summarize the common preparation methods of MOFs-based oil–water separation membranes and the research progress of different MOFs-based membranes, including the ZIF series, UiO series, MIL series, etc. Finally, we also analyze the challenges faced by MOFs-based membranes in oil–water separation and provide an outlook on their future development and application.

Carbonaceous nanofibrous membranes with enhanced superhydrophilicity and underwater superoleophobicity for effective purification of emulsified oily wastewater

High performance oil–water separation membranes with stable physical–chemical properties are highly desirable for the treatment of emulsified oily wastewater in various conditions. Carbonaceous nanofibrous membranes are promising due to several merits, including good thermal resistance, chemical inertness, non-toxicity, and harmlessness. However, the hydrophobicity and oleophilicity of carbon, as well as the poor mechanical property of carbon nanofibers, make it challenging to use the corresponding membrane for the separation of oil-in-water emulsions. Herein, we demonstrate a facile and effective strategy to fabricate a superhydrophilic and underwater superoleophobic carbonaceous nanofibrous membrane. The mechanical property and surface wettability of the membrane could be well regulated through heteroatom doping and thermal induced oxidation. As a result, the obtained carbonaceous nanofibrous membrane exhibited intriguingly durable mechanical flexibility and oil–water selective wettability, which were comparable to that of polymeric membranes. In the meanwhile, a plausible mechanism for the underwater superoleophobicity of the membrane was proposed based on a series of structural analyses and molecular dynamic simulations. With the synergy of developed pores and high oil–water selective wettability, the obtained carbonaceous nanofibrous membrane was effective for separating various oil-in-water emulsions. Moreover, the membrane, thanks to its gratifying underwater anti-oil adhesion property, could be efficiently reused after a simple process of hydraulic washing, demonstrating great potential for the purification of emulsified oily wastewater.

A harsh environment resistant robust Co(OH)2@stearic acid nanocellulose-based membrane for oil-water separation and wastewater purification

Traditional membranes are inefficient in treating highly toxic organic pollutants and oily wastewater in harsh environments, which is difficult to meet the growing demand for green development. Herein, the Co(OH)2@stearic acid nanocellulose-based membrane was prepared by depositing Co(OH)2 on the nanocellulose-based membrane (NBM) through chemical soaking method, which enables efficient oil/water mixtures separation and degradation of pollutants by photocatalysis in harsh environments. The Co(OH)2@stearic acid nanocellulose-based membrane (Co(OH)2@stearic acid NBM) shows good photocatalytic degradation performance for methylene blue pollutants in harsh environment, and has significant degradation rate (93.66%). At the same time, the Co(OH)2@stearic acid NBM with superhydrophobicity and superoleophilicity also exhibits respectable oil/water mixtures separation performance (n-Hexane, dimethyl carbonate, chloroform and toluene) under harsh environment (strong acid/strong alkali), which has an excellent oil-water mixtures separation flux of 87 L·m−2·h−1 (n-Hexane/water) and oil-water mixture separation efficiency of over 93% (n-Hexane/water). In addition, this robust Co(OH)2@stearic acid NBM shows good self-cleaning and recycling performance. Even though seven oil-water separation tests have been carried out under harsh environment, it can still maintain respectable oil-water mixture separation rate and flux. The multifunctional membrane has excellent resistance to harsh environments, oil-water separation and pollutant degradation can be performed even in harsh environments, which provides a convenient way to treat sewage under harsh conditions efficiently and has great potential in practical application.

Preparation of underwater superoleophobic ZIF-67 composite membrane with high antibacterial activity and emulsion separation efficiency

Bacteria and oils can be found in domestic sewage and wastewater from biomedical industries, however, traditional membranes have limitation in bacterial resistance, so it is high demand to design oil-water separation membranes with antibacterial activity. In this work, a novel TCN-ZIF-67/PVA@NM composite membrane with underwater superoleophobic property was prepared by in-situ growth method. The effects of ZIF-67 on emulsion separation and antibacterial activity were investigated in details. Results show that TCN-ZIF-67/PVA@NM have high separation efficiencies for oil-in-water emulsions stabilized by SDS, CTAB or Tween 80. Due to the positive charge of ZIF-67, the separation flux shows a trend of SDS>CTAB>Tween 80. The separation efficiency and antibacterial activity of the composite membrane increased and the separation flux decreased with the increase of the particle size of ZIF-67. In addition, the composite membrane had good inhibitory effects against the biofilm formation of S. aureus and MASR. It was found that when the reaction time was more than 6 h, the separation efficiencies of oil-in-water emulsions were more than 99%, and the bacterial inhibition ratios against S. aureus and E. coli. and biofilm inhibition ratios against S. aureus and MASR were more than 90%. When separating the emulsion containing bacteria, the composite membrane can simultaneously purify the emulsion and kill the bacteria in the water. Overall, ZIF-67 plays key roles in both emulsion separation and bacterial resistance, and the ZIF-67 composite membrane shows a promising potential in oil-water emulsion separation application.

Fish-scale inspired superoleophobic membrane from cellulose: A Review

Nature-inspired technology has been investigated widely. Anti biofouling properties of fish scale has inpired to improve membrane performance. Biofouling affects an oil-water separation membrane. The bacterial, coagulant, and hydrophobic oils attach to the membrane surface, demanding periodic cleaning. To overcome the problems, surface modification materials are introduced namely superoleophobic surface. The superoleophobic surface promises antifouling, high flux, and high separation efficiency. Superoleophobic surfaces are inspired by the scales on fish that form a hydrogel-like layer on their surface. The hydrogel repels oil and any organic materials, keeping the surface clean. The hydrogel of fish scales can be mimicked by cellulose-based materials. A dense layer of hydroxyl groups absorbs a lot of water and forms a hydrogel bond. The membrane with the cellulose hydrogel-like structure will perform a superoleophobic characteristic surface. The characteristic can be utilized as a functional membrane for oil-water separation. This article reviews the principle, mechanism, current development, and future challenges of bioinspired superoleophobic surfaces from cellulose-based materials for membrane applications.

Polylactic acid/multi-wall carbon nanotubes composite fibrous membrane and their applications in oil-water separation

Because of the rising consumption of oil, the oily pollutants contained in wastewater have caused great damage to the ecological environment. Herein, we report a novel composite PLA fibrous membrane for oil-water separation. First, a series of hydrophobic polylactic acid/multi-wall carbon nanotubes (PLA/CNTs) composite fibrous membranes were fabricated via electrospinning. To modify the membranes’ crystalline structure, the as-prepared PLA/CNTs composite fibrous membranes were subsequently treated by being immersed in an acetone/ethanol mixed solution for 5 min. FTIR and XRD were applied to thoroughly investigate the crystalline modification's mechanism and effects on the oil-water separation capability of the as-prepared composite fibrous membranes. With the introduction of CNTs and the crystalline modification, a low polar, rough and porous surface was endowed to the as-prepared fibrous membranes, enhancing their hydrophobicity and oil-water selectivity. The oil uptake of the as-prepared fibrous membrane could reach 114.01 g/g. The water contact angle in the air could reach 134.2° while the water contact angle under oil can reach 157.3° Therefore, such high separation capability in the oil-water mixture will make the PLA/CNTs composite fibrous membranes promising candidates for oil-water separation applications.

Self assembled PP membrane with photocatalytic self-cleaning performance for efficient oil/water emulsion separation

In this study, a super-hydrophobic self-cleaning fluorinated Zr-MOF nano-hybrid membrane (TF-DUT-52/PP) was developed by in-situ growth of modified MOF onto polypropylene membrane. DUT-52 is a new zirconium-based MOF with face-centered cubic topology and bearing stiffness. The hydrophobic group—trifluoroacetamide group is introduced into its monomer, which makes the final prepared membrane have excellent high porosity, durability and superhydrophobicity, and is an attractive oil-water separation membrane. The separation efficiency of the membrane for three different oil-water emulsion is more than 98%, and the separation flux is also very high (more than 500 Lm-2h-1bar-1). In addition, due to the Zr metal on the TF-DUT-52 node on the membrane surface, the membrane has good photocatalytic self-cleaning performance. Under ultraviolet light irradiation, it has high photocatalytic activity for organic pollutants on the membrane surface (the degradation efficiency is more than 85%). Therefore, in the foreseeable future, TF-DUT-52/PP membrane, as an anti-fouling membrane of a new generation of super hydrophobic/super lipophilic materials, has high throughput and stability, and provides a new idea for the removal of oily wastewater.

Silicone decorated polycaprolactone electrospun fibrous membranes for oil/water separation

Due to the rapid development of modern industry, oily wastewater, which contained poisonous chemicals, would cause damage to marine fishery resources, and finally threaten human health. To address this issue, we herein report a fibrous membrane for oil-water separation. Firstly, the silicone polymer was synthesized by the in situ polymerization of aminopropyl trimethoxysilane and 3-glycidyloxypropyl trimethoxysilane in a polycaprolactone (PCL) solution. Then, the silicone decorated PCL (S-PCL) fibrous membranes were then prepared via electrospinning the synthesized solution. The decorated silicone offers a good porous structure for fibrous membranes. Specifically, the decorated silicone endows the PCL fibrous membrane with a good lipophilic/hydrophobic performance with a water contact angle of 169° under oil. More importantly, the obtained fibrous membrane owned a good oil-water selectivity. The oil droplets could be spread and absorbed by the fibrous membrane in water within 5 s. Such efficient separation for oil and water mixtures, endowed by silicone, will make the PCL fibrous membrane an environmental-friendly candidate for treating oily wastewater.

Bioinspired Dynamic Antifouling of Oil‐Water Separation Membrane by Bubble‐Mediated Shape Morphing

AbstractOil–water separation membranes easily fail to oil foulants with low surface energy and high viscosity, which severely limits these membranes’ applications in treating oily wastewater. Herein, an oil–water separation membrane by bioinspired bubble‐mediated antifouling strategy is fabricated via growing hierarchical cobalt phosphide arrays on stainless steel mesh. The as‐prepared membrane is superhydrophilic/superaerophobic and electrocatalytic for hydrogen evolution under water, which helps to rapidly generate and release abundant microbubbles surrounding the oil‐fouled region on the membrane. These microbubbles can spontaneously coalesce with the oil foulants to increase their buoyancy and warp their interface tension by morphing the oil shape. And this spontaneous coalescence also increases the kinetic energy of oil foulants resulting from the decreased bubbles’ interface energy and potential energy. The synergy of the warped interface tension, increased buoyancy, and kinetic energy drives the efficiently dynamic antifouling of this membrane. This dynamic antifouling even can remove some solid sediment such as oily sand particles that causes more serious fouling of the membrane. Thus, this membrane maintains high flux (>11920 L m−2 h−1 bar−1) in the long‐term separation of oil–water and oil–sand–water emulsions by dynamically recovering the decayed flux on demand, which exhibits great potential in treating industrial oily wastewater.

Fabrication of Photo-Responsive Mesh Membrane with Surface-Engineered Wettability for Oil-Water Separation and Photocatalytic Degradation of Organic Pollutants.

A photo-responsive TiO2-coated stainless-steel mesh membrane (TiO2@SSM), possessing unique surface wettability, was fabricated. This TiO2@SSM membrane is found to be capable of separating oil and water from oily water and has the potential to carry out photocatalytic self-cleaning and/or the degradation of organic pollutants present in water. The fabrication of TiO2@SSM is quite simple: titanium dioxide (TiO2) nanoparticles were spray-coated onto stainless steel microporous mesh (SSM) substrates and annealed at the temperature of 500 °C. The fabricated TiO2@SSM membrane was structurally and morphologically characterized by XRD, FE-SEM, EDX, and elemental mapping. The contact angle measurements using a goniometer showed that the fabricated TiO2@SSM membrane surface is superhydrophilic and superoleophilic in air and superoleophobic under water. This is a favorable wetting condition for the water passing oil-water separation membrane, and this water passing property of the membrane eased the common problem of the fast clogging of the membrane by oil. An oil-water separation efficiency of about 99% was achieved, when the TiO2@SSM membrane was used as the separating medium in the gravity-driven oil-water separation system, unlike the uncoated stainless steel mesh membrane, which allowed both oil and water to pass together. This confirmed that the oil-water separating functionality of the membrane is attributed to TiO2 coating on the stainless steel mesh. The photocatalytic degradation property of the TiO2@SSM membrane is an added advantage, where the membrane can be potentially used for self-cleaning of the membrane's surface and/or for water purification.

Facile fabrication of SWCNT film-based superhydrophobic cotton fabrics for oil/water separation and self-cleaning

With the increase of oily waste, oil-water separation has become an urgent and difficult task. However, the current challenge is to fabricate such efficient membrane materials for oil-water separation. Herein, superhydrophobic single-walled carbon nanotubes (SWCNTs)/cotton fabric (CF) was prepared via a dry process. In which the ultrathin SWCNT films with a low content of hydrophilic groups were prepared by a facile floating catalyst chemical vapor deposition method and directly deposited on CF without solvent dispersion. The obtained SWCNT@CF was further treated by 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane (POTS). Due to the synergistic effect of SWCNTs and POTS, the POTS-modified SWCNT@CF displayed excellent superhydrophobicity with a water contact angle（WCA）of ∼163.3°, and consequently can be further used as a membrane for oil-water separation. These superhydrophobic fabrics have high oil/water separation efficiency (99.2% for dichloromethane/water) and high oil flux (28.71 ×103 L·m−2·h−1 for dichloromethane/water). Even after 25 separation cycles, oil/water separation efficiency and oil flux maintain 98.8% and 25.15 × 103 L·m−2·h−1, respectively. In addition, it exhibits high separation efficiency (∼99%) for water-in-oil emulsion. Moreover, under extreme environmental conditions, the contact angle of the obtained POTS-modified SWCNT/CF was maintained at ∼155°, keeping stable superhydrophobicity. This reported preparation strategy of superhydrophobic fabrics is environmentally friendly, low cost, sustainable, and easy to scale up, thereby exhibiting great potential in practical applications.

Transfer-Printed Environmental-Friendly Anisotropic Filter with Laser-Controlled Micropores for Efficient Oil/Water Separation

Water is indispensable for sustaining life on Earth. Oil–water mixtures/or emulsions from industrial waste and other sources are a serious environmental concern for both human beings and aquatic life. Specially treated meshes and textiles with opposing wettability for oil–water separation have been widely reported as a solution to this challenge. Nonetheless, such membranes are hindered by certain drawbacks, including high manufacturing costs, usage of harmful chemicals, and lack of diverse applicability. Here, we report a facile method to fabricate Janus oil–water separation membrane with a controllable pore structure that has a unique directional flux rate. The superhydrophobic (SHB) layer of the membrane is formed by transfer-printing (TP) carbon soot particles onto a polydimethylsiloxane (PDMS)-coated paper surface. Meanwhile, a spin-coated thin layer of chitosan on the other side of the film served as a hydrophilic (SHL) and underwater oleophobic face. A pulsed laser beam is used to produce micropores with conical structures. The separation ability of the membrane for both light oil–water and heavy oil–water mixtures is thoroughly investigated. Moreover, the significance of the pore shape and the size is also elucidated. The flexible Janus membrane showed high thermal stability and ideal (i.e., 99.8%) separation efficiency. The membrane can be produced over a 151 cm2 size range. Besides having flexibility and superior performance, the fabricated membrane is environmentally friendly and economically viable. This work establishes a scalable basis for efficient and low-cost oil/water membranes from non-porous substrates.

Binary nanofibrous membranes with independent oil/water transport channels for durable emulsion separation

Oil fouling threatens the stability of water permeability for oil-water separation membrane. Homogeneous hydrophilic surface modification provided an opportunity to prevent oil pollution, but failed to maintain stable water traverse due to oil accumulation. Here we report a binary nanofibrous membrane (BNM) through co-electrospinning technique and Michael addition reaction, where hydrophilic polyacrylonitile (mPAN) and hydrophobic poly (vinylidene fluoride) (mPVDF) nanofibers with certain ratio constructed independent water/oil transport channels respectively. The fabricated binary nanofibrous membrane provides stable permeance and high separation efficiency (>99.5%) for viscous oily emulsions in continuous cross-flow filtration. The oil droplets transport experienced deposition, migration, coalescence and removal to significantly alleviate fouling. The binary nanofibrous membrane with heterogenous wetting property provides durable permeation and separation efficiency for durable emulsion separation, which sheds light on a new approach for the development of ideal oil/water separation membranes.