High Oil Flux Research Articles

Smart anti‐fouling and self‐repairing polymer brushes for efficient oil–water separation

AbstractThe increasing water pollution problem poses a demand for oil–water separation materials, but preparing separation materials with high efficiency and excellent durability remains a great challenge. In this work, we use a diblock polymer brush of polydimethylsiloxane (PDMS) and poly(N,N‐dimethylaminoethyl methacrylate) (PDMAEMA) based on cotton fabric to prepare oil–water separation membranes with high efficiency, good durability, and intelligent self‐repairing properties. Lubricating PDMS brushes reduces the fouling adhesion due to its low surface energy and high flexibility. pH‐responsive PDMAEMA brushes provide good hydrophobicity and an intelligent self‐repairing effect. The prepared Co‐PDMS‐PDMAEMA has high oil flux (>30,000 L m−2 h−1) and high separation efficiency (>99%) even after 10 cycles and its surface character can be recovered under acidic conditions. Overall, the modified cotton fabric made by such a versatile technique is promising in oil–water separation.

Superoleophilic cotton fabric decorated with hydrophobic Zn/Zr MOF nanoflowers for efficient self-cleaning, UV-blocking, and oil–water separation

Oil spills significantly threaten aquatic life, human health and the environment, necessitating oil–water separation methods. To address these environmental concerns, a hydrophobic Zn/Zr bimetallic metal–organic framework nanoflowers (H-Zn/Zr MOF-NF) functionalized superhydrophobic cotton fabric is developed for oil–water separation. Hydrophilic amine-terminated bimetallic Zn/Zr MOF with distinctive flower-like morphology is hydrothermally synthesized and functionalized with myristic acid. Finally, cotton fabric is coated with a hydrophobic emulsion of H-Zn/Zr MOF-NF and polydimethylsiloxane (PDMS) via dip-coating,enhancing surface roughness and lowering surface energy. The developed superhydrophobic cotton fabric shows exceptional water-repellency with a water contact angle (WCA) and water slidingangle (WSA) of 161° and 4°, respectively. The Zn/Zr MOF-NF coated superhydrophobic cotton fabric with a porous structure efficiently separates diesel oil, n-hexane, toluene, and chloroform from water mixtures with over 98% separation efficiency and high flux. The coated cotton fabric demonstrates remarkable reusability, upholding superior separation efficiency over 95% and retaining WCA at 156° after 12 cycles with excellent physical and chemical stability. The modified cotton fabric also exhibits enhanced UV-blocking properties and self-cleaning characteristics. The designed emulsion is also applied to other surfaces, such as sponge, wood, and filter paper, demonstrating promising superhydrophobicity. This study opens new possibilities for manufacturing multifunctional superhydrophobic surfaces for oil–water separation applications using bimetallic hydrophobic MOFs.

Fabrication of hydrophobic PI nanofibrous membrane with controllable pore structures

Polyimide (PI) has garnered increasing attention in the field of membrane technology owing to its excellent comprehensive performance. In this work, PI nanofibrous membranes with a controllable pore structure were fabricated by the thermal imidization of electrospun polyamide acid (PAA) nanofibrous membranes. Polytetrafluoroethylene (PTFE) and poly(tetrafluoroethylene-hexafluoropropylene) (FEP) particles were introduced into the PAA nanofibrous membrane with the aim of enhancing the membrane's hydrophobicity and regulating its pore structure by electrospraying the PTFE/FEP mixed aqueous dispersion. During the thermal imidization process, melt casting of FEP particles occurred, leading to the adhesion of PI nanofibrous membranes and subsequent regulation of the membrane's pore structure. Meanwhile, due to the imidization temperature being lower than PTFE’s melting temperature, the unmelted PTFE particles would further enhance the membrane’s hydrophobicity. We have successfully provided a novel method for fabricating PI nanofibrous membranes with controllable pore structures and excellent hydrophobicity to expand their applications in membrane separation. Owing to the hydrophobicity and lipophilicity, the obtained PI nanofibrous membranes were applied to oil-water (kerosene/water) separation to characterize the separation performance. The results showed that, following the regulation of the pore structure, the PI nanofibrous membranes exhibited a high oil flux (203.83 L/m2·h) and separation efficiency (＞99.00%) without external pressure.

Poly lauryl methacrylate modified superhydrophobic Fe foam, with excellent stability and magnetic oil/water separation ability

With the acceleration of the industrial process, oil-water separation is an urgent problem for oil spill accidents and wastewater treatments. Exploiting superhydrophobic materials applied in harsh environments and remote drives remains a significant challenge in solving oil moisture problems. An alternative strategy to solve this problem has been demonstrated by decorating poly lauryl methacrylate (LMA) on Fe foam via the solution polymerization method. The as-prepared Fe foam possesses good superhydrophobicity (>150°) under broad pH (1 < pH < 12) and a wide temperature range (−55°C-180 °C). Furthermore, outstanding separation efficiency (>99.1%), high cycle stability (>50 times), and high oil flux (63.7–114.6 kL m−2 h−1) against diverse oil/water mixtures can be realized under gravity. Interestingly, oil harvesting capacity above or beneath the water can be realized by remote magnetic driving as well.

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.

Superhydrophobic fluorinated nanoparticle-modified surfaces for fast, efficient, and selective elimination of oil from water

An effective, low-cost method for fabricating superhydrophobic surfaces was investigated. A mixed solution of tetrahydrofuran, 2,3,4,5,6-pentafluorostyrene, and Al₂O₃ nanoparticles was introduced to the original materials to obtain superhydrophobic modified polypropylene (M-PP), cotton fiber (M-CTF), and polyurethane foam (M-PUF). The novelty of this work includes the development of cost-effective, stable materials with superhydrophobic surfaces for extreme water-repellency. The prepared materials were evaluated for hydrophobicity, oil absorption capacity, separation efficiency, oil flux, and reusability using several techniques. They all showed superhydrophobicity with water contact angles higher than 151 ± 0.5°. The results also reveal that the materials exhibited significant oil absorption capacities between 9.8 and 40.3 times their own weights, high separation efficiency (>97.2%), oil flux (>41,110 Lm⁻²h⁻¹), and reusability (>100 times) in the separation of oil-water. Moreover, all the treated materials demonstrated excellent oil selectivity in different salty waters. The samples could still retain outstanding separation even after 10 abrasion cycles with sandpapers. The excellent anti-intrusion and anti-abrasion behavior make the prepared materials promising for oil/water separation in harsh environments.

Synthesis of multifunctional superwettable zinc nanoparticle with pH-bidirectional responsive for efficient emulsion separation

Smart pH-bidirectional responsive material has been presented based on zinc nanoparticles with smart surfaces adaptably transform wettability in mutual directions between the superhydrophobicity-superoleophilicity and the superhydrophilicity-underwater superoleophobicity depending on the pH. The smart material fabrication was prepared by immersing the fabric in AA-co-VTES-ZnO (composite A) and APTES-FOTS-ZnO (composite B) reactions. The material was synthesized by free radical polymerization. Characterization by FTIR, and SEM/EDX explained that the chemical compositions were uniformly distributed through the smart fabric surface caused by the strong chelating bond between the hydroxide, carboxylates, and silane active surfaces. The chemical stability, mechanical durability, and separation test results revealed selective separation efficiency for oil/water separation with efficacy ≥99 % and high satisfactory oil flux 7000–8000 L.h−1.m−2 and water flux (5500–6500 L.h−1.m−2). Moreover, the water contact angle (WCA) for neutral water was showing at 167° indicating powerful superhydrophobic properties, and for acidic/basic water was absorbing from 143/153° to 0° over time indicating superhydrophylic properties. Underwater treatment showed that the smart fabric has superoleophobic behavior with around 150° oil contact angle (OAC). Various weights and % NaCl immersion tests also have been applied for mechanical and chemical stability tests. The results displayed brilliant stability under severe conditions confirming great WCA after repeating and increasing mass and concentration. For oil removal and emulsion test, dyed oil was rapidly absorbed within 2 s and oil/water emulsions were easily separated by developed fabric with a good flux and separation efficacy of over 97 %. Interestingly, the prepared materials can also be efficiently and continuously separated for complicated oil/water/oil mixtures without particular treatment.

Synthesis of novel smart pH-sensitive modified silica nanoparticles for controllable oil-water separation

The newly designed superwettable polymers with external stimuli-responsive behavior have been greatly proposed a great research interest in the oil industry due to their fast and simple mechanism process. Herein, the development of the advanced silica-based pH-responsive materials linked with hydrophilic 3-(aminopropyl)triethoxysilane (APTES) and hydrophobic 1H,1H,2H,2H-perfluorooctyl-triethoxysilane (FOTS) chelating ligands have been designed for oil/water separation by a facile dip-coating process. This smart material can propose an excellent wettability conversion between superhydrophobicity-superoleophilicity and superhydrophilicity-underwater superoleophobicity, favorable stability, and durability, resulting in efficient separation for oil/water mixture. These properties were observed from the well-defined 3D porous surface of the smart materials when they were coated on the fabric surface. Furthermore, characterization described that the material compositions were chemically reacted and distributed throughout the smart fabric surface caused by the robust chemical interaction between the functional groups such as hydroxide, carboxylate, and silane. The water contact angle (pH≈10) was displayed at 167-160° and for acidic water (pH≈2) was ranging from 143-0° over 100 s denoting outstanding superhydrophobic and superhydrophilic features respectively. Underwater measurement pointed out that the smart fabric also has a great superoleophobicity for oil contact angle (150°). Moreover, the series of test results revealed a selective separation for oil/water system with efficacy > 98% and high oil flux ranging from 7200 to 7900 L.h−1.m−2 as well as water flux (5300–6200 L.h−1.m−2). Therefore, these smart materials with fabric and non-fabric preparation have a direct environmental impact on real samples and they can largely dominate various oily wastewater/oil spills clean up.

Fluorine-free superhydrophobic PET fabric with high oil flux for oil–water separation

Superhydrophobic fabrics with high oil–water separation efficiencies have recently attracted considerable attention because of the frequent oil pollution created by industry. However, the relationship between hydrophobicity and the separation efficiency needs to be clarified, and water-blocking materials used to separate heavy oil must be further explored. In this study, we prepared hydrophobic fabrics by a one-pot sol–gel approach with different concentrations of hexadecyltrimethoxysilane (HDTMS), polymethylhydrosiloxane (PMHS), and hydroxyl-terminated polydimethylsiloxane (HTPDMS). The surface chemistries of the superhydrophobic fabrics were systematically studied, and it was found that the SiO2 nanoparticles created a micro/nanoscale roughness on the surface, endowing the fabric with superhydrophobicity. By changing the component ratios, five samples with elevated hydrophobicity were fabricated. Interestingly, the hydrophobicity of the fabric had a positive effect on the separation efficiency and the oil flux. Importantly, when the contact angle increased from 132.5° to 151.3°, the oil flux of heavy oil increased from 13,028 ± 563 L m−2 h−1 to 20,473 ± 928 L m−2 h−1. The superhydrophobic fabric also exhibited a high resistance to mechanical abrasion and self-cleaning properties. Thus, we provide a pollution-free, anti-oil fouling, high-oil-flux, high-separation-efficiency, water-blocking fabric for the separation of oils from water.

One-step fabrication of biodegradable superhydrophobic PLA fabric for continuous oil/water separation

Various types of functional materials incorporating superhydrophobic components have been rapidly developed for efficient oil/water separation. The post-processing of these used separated materials remains a challenging problem due to their non-biodegradable characteristics in natural environments, thus easily contributing to secondary contamination. Herein, we report a biodegradable superhydrophobic PLA fabric with hierarchical coral-like micro/nano structures by a one-step spraying method. The as-prepared PLA fabric was found to be both superhydrophobic and superoleophilic with a static water contact angle of 161 ± 2° and an oil contact angle of 0°. In addition, the as-prepared PLA nonwoven fabrics also revealed efficient continuous oil separation efficiency (>97.5%) and tiny water droplet collection efficiency, as well as high oil flux ranging from 2239 L·m−2·h−1 to 59,713 L·m−2·h−1. Furthermore, these fabrics retained their inherent wetting property and oil separation ability in a variety of acidic and basic solutions, 3.5 wt% NaCl solution, hot (100 °C), and freezing (0 °C) temperatures. This study provides a novel and environmentally friendly method for preparing biodegradable oil–water separation materials with green post-treatment characteristics when compared to the non-biodegradable separation materials, indicating potential applications in the fields of green water treatment and petroleum refining.

Multi-functional flame-retardant superhydrophobic ceramic fiber felt: Oil/Water mixture separation and oil mist interception

Developing robust superhydrophobic surfaces integrating flame retardancy and multitasking oil separation performance is important but challenging for the restoration of environmental pollution caused by the discharge of mixtures containing oils. Herein, a kind of high-efficiency and flame-retardant superhydrophobic ceramic fiber felt (SCFF) is facilely prepared by chemical vapor modification (CVD) to realize efficiently oil/water mixture separation and oil mist interception. Through the CVD of ceramic fiber with tetrachlorosilane and trimethylchlorosilane, methyl terminated silicon-oxide compound is grafted on the surface of the material, which instantly transfers it from hydrophilic to superhydrophobic in 1 min. The modified surfaces are highly water repellent (water contact angle above 156°) that keep stable in various organic solvents and under high temperature (260 ℃) treatments even after burning. The result of oil/water mixture separation shows that the SCFF has excellent separation efficiency (98.78%) and high oil flux (35,939 L·m−2·h−1), which remain stable after 10 repeated cycles. In the oil mist environment, the double-layer SCFF can intercept 96.04% of oil droplets from the airflow. Further, the mechanism of oil leaking and intercepting is illustrated. These features make the SCFF promising for the remediation of oil spills and high-temperature oil mist interception.

Constructing tubular/porous structures toward highly efficient oil/water separation in electrospun stereocomplex polylactide fibers via coaxial electrospinning technology

The wide application of biodegradable polymers in wastewater treatment is of great significance because it can greatly reduce the risk of secondary pollution during the employ of polymers. In this work, a coaxial electrospinning technology was applied to prepare the polylactide (PLA)-based fibers. The solution of poly(L-lactide) (PLLA), poly(D-lactide) (PDLA) and γ-Fe2O3 nanoparticles was used to construct the tube wall, while the mineral oil was used as the core. As a result, the PLA fibers exhibited the tubular hollow structure with extensive pores on the tube wall after mineral oil was removed by solvents. The prepared PLA membrane exhibited superhydrophobicity and high porosity due to the special porous structure of the fibers. The maximum adsorption capacity toward castor oil was 219.5 g g−1, exhibiting excellent oil adsorption ability. In addition, the membrane showed high oil flux of 57324.8 L m-2h−1 and good oil/water separation ability. The gravity-driven separation flux of emulsion achieved 3401.4 L m-2h−1, and it still remained high level during separating acidic, alkaline and hypersaline emulsions. Besides, the high mechanical property of the membrane endowed it with excellent cycling stability. This work paves the way for the practical applications of environmentally friendly adsorption/separation membranes in oil/water cycling separation.

Fabrication of superwetting, anti-icing nickel-cobalt carbonate hydroxide coated-aluminosilicate fiber paper for oil-water separation

Fabricating low-cost and high-efficiency oil-water separation superwetting materials for the demand of oil spilling treatment remains a great challenge. Herein, a superwetting aluminosilicate fiber paper decorated by flower-like nickel-cobalt carbonate hydroxide (NiCo-CH) nanostructures was prepared via the hydrothermal method and chemical modification with stearic acid (SA) or 1H, 1H, 2H, 2H-Perfluoroalkyltriethoxysilane (FAS-17). The superhydrophilic multi-layers nanoflowers combing with nanoflakes were uniformly distributed on the surface of aluminosilicate fiber. The superhydrophilic aluminosilicate fiber was then modified by the SA to obtain the superhydrophobic aluminosilicate fiber (SA-NiCo-CH@Al 2 SiO 5 FP). The SA-NiCo-CH@Al 2 SiO 5 FP revealed high separation efficiency (> 95.4%) for both light oils and heavy oils, and high oil flux (417 L m −2 h −1 –71,656 L m −2 h −1 ). Furthermore, the SA-NiCo-CH@Al 2 SiO 5 FP can also remain superhydrophobicity under various harsh conditions, such as dust, sand impact, acid or alkali, and low-temperature environments. This study revealed an inexpensive and simple-fabricated multifunctional superwetting material, which provides promising avenue for future applications in oil-water separation.

Robust preparation of flexibly super-hydrophobic carbon fiber membrane by electrospinning for efficient oil-water separation in harsh environments

Conventional polymer filtration membranes suffer from low efficiency, easy fouling and serious degradation in harsh environments, due to its low chemical and separation stability. Herein, a flexible super-hydrophobic carbon nanofiber membrane (CFMHF) was prepared using electrospinning and subsequently fluorinated treatment. The zinc acetate (ZnAc) was introduced to form pores in carbon fibers during heat treatment, and the pore-forming mechanism was well discussed. As a result, the flexibility and specific surface area of the carbon fibers were increased. The CFMHFs exhibited excellent super-hydrophobicity (water contact angle, WCA = 155.9°), high oil flux (3590 L m−2 h−1) and excellent oil-water separation performance. Driven by gravity alone, the separation efficiencies of the CFMHFs for non-emulsified oil-water and emulsified water-in-oil mixtures were both more than 98%. More importantly, the as-prepared CFMHFs showed good stability in harsh conditions, including high or low temperature, strong acid and alkali solutions, organic solvents and salt solutions. This strategy has directive significance for designing high performance oil-water separation membranes.

Fabrication of sustainable and durable bio-polybenzoxazine based superhydrophobic cotton fabric for efficient oil/water separation

Sustainable and durable superhydrophobic cotton fabric was fabricated by combining the eco-friendly enzyme-etching approach and hydrophobic modification. The rough surface of the fiber was constructed by cellulase etching. Superhydrophobic cotton fabric was obtained from further deposition of cardanol-based polybenzoxazine (PC-aps) by dip-coating and thermal curing. The as-prepared PC-aps coated cotton fabric (PC-aps/ECF) possessed special wettability with a water contact angle (WCA) of 154.6° ± 0.4° and an oil contact angle of 0°. The PC-aps/ECF demonstrated exceptional mechanical durability and environmental stability to sandpaper abrasion, ultrasonic treatment, accelerated laundering, corrosive liquids, and high temperature. Moreover, the PC-aps/ECF had excellent separation performance for several oil/water mixtures with high oil flux (as high as 6744.6 ± 177.9 L m−2 h−1) and separation efficiency (all above 99.76 %). Especially, the separation of water-in-oil emulsions was achieved by external pressure filtration using the home-made PC-aps/ECF@PU sponge@ PC-aps/ECF composite with the oil flux up to 27473.2 ± 730.7 L m−2 h−1 bar−1 and the separation efficiency as high as 99.65 %. The outstanding durability, high separation performances, and excellent reusability of PC-aps/ECF make it very suitable for waste-water treatment.

Freely switchable super-hydrophobicity and super-hydrophilicity of sponge-like poly(vinylidene fluoride) porous fibers for highly efficient oil/water separation

Highly efficient oil/water separation ability is a prerequisite for the actual application of the membranes in oily sewage treatment, which is closely related to the surface feature and the porous structure of the membranes. In this work, the electrospun poly(vinylidene fluoride) (PVDF) porous fibers were firstly fabricated through blend-electrospinning with poly(vinyl pyrrolidone) (PVP) and then treating in distilled water. The results showed that the fibers exhibited the sponge-like porous structure, and a few PVP was reserved in the fibers due to the relatively good interaction between PVDF and PVP. The fibrous membrane exhibited high porosity, super-wettability with freely switchable super-lipophilicity and super-hydrophilicity. The oil adsorption capacities as well as the oil and water fluxes were measured, and the oil adsorption capacities were varied in the range of 22.7–76.0 g/g, and oil and water fluxes were 54,737.3 and 56,869.9 L/(m2h), respectively. Specifically, the PVDF porous fibrous membranes showed excellent separation abilities and they could highly efficiently separate oil from oil-in-water emulsions or separate water from water-in-oil emulsions, accompanied with the extremely high water or oil flux. This work confirms that the PVDF membranes composed of the porous fibers can be used in wastewater treatment.

An instant oil separation by octadecyl-polysiloxane-reticulated recyclable superhydrophobic polyester fabric

Of all the environmental concerns, water pollution by oily wastewater is arguably one of the most severe problems facing humanity. This universal challenge needs to resolve the effective oil–water​ separation. Hither, an excellent water repellent superhydrophobic material propelled by the lotus leaf were prepared by cross-linking of fumed silica and octadecyltrichlorosilane via polycondensation reactions on polyester fabric by a one-step dip-coating method. The constructed octadecyl-polysiloxane networked silica material exhibits superhydrophobic behavior at a maximum high-water contact angle of 178 o . AFM and SEM morphological studies showed nanoscale hierarchy structures forming large-scale microstructures, and they were well-anchored with the fabric. A high oil (dichloromethane) flux up to 1604 L m- 2 h- 1 with a separation efficiency of nigh >99.5% was obtained even after repeating use for ten separation cycles. The material showed a fast and effective oil–water separation under gravity and has excellent stability over time, which makes it an ideal option for treating industrial oily wastewater. • Recyclable superhydrophobic nanostructured material coated polyester fabrics. • A hierarchy membrane structure comprising nanoscale and microscale domains. • Membrane surface with water contact angle of 178°for rapid passing of organics. • Quick and remarkable separation of oily water under gravity.

Fabrication of a superhydrophobic fabric with a uniform hierarchical structure via a bottom-blown stirring method for highly efficient oil–water separation

Highly efficient and multifunctional superhydrophobic fabrics have attracted widespread attention because of the urgent need for oil–water separation technologies. A superhydrophobic polyester fabric with a uniform surface roughness was fabricated via a novel bottom-blown stirring method. The water contact angle increased from 95.3° ± 1.1° of pure polyester fabric to 152.5° ± 0.7°, and the improved uniform roughness led to superhydrophobic fabric with a high separation efficiency (>99.5%) and oil flux (29443 L m−2 h−1), even after 10 cycles of oil–water separation. As the control group, the fabric prepared via traditional magnetic stirring methods could not separate the oil from the water after two cycles. Furthermore, the superhydrophobic fabric showed high mechanical abrasion resistance, even after 100 abrasion cycles on sandpaper (1000 mesh). In addition, the superhydrophobic fabric showed excellent self-cleaning properties and chemical stability. This work provides a new method for fabricating superhydrophobic fabrics with uniform roughness properties that lead to high separation efficiencies and abrasiveness for practical applications in oil–water separation.

Fabrication of Magnetically Inorganic/Organic Superhydrophobic Fabrics and Their Applications.

In order to solve the problem caused by oil spills and organic solvent contamination, novel magnetically inorganic/organic superhydrophobic fabrics are fabricated via a facile method. Cotton fabrics are immersed in a mixture of functionalized Co0.2Mg0.8Fe2O4 (FCMFO) nanoparticles, vinyl-terminated polydimethylsiloxane (VPDMS), trimethylolpropane triacrylate, and 2-hydroxy-2-methylpropiophenone before UV irradiation for 100 s to obtain the multifunctional superhydrophobic fabrics with magnetic property. The coated fabrics show excellent superhydrophobicity, and the water contact angle is 157.1° when the mass ratio of FCMFO nanoparticles to VPDMS is 0.3. These superhydrophobic fabrics have high oil/water separation efficiency (98.7% for dichloromethane/water) and high oil flux (71,506 L·m-2·h-1 for dichloromethane/water). Even after 20 separation cycles, oil/water separation efficiency and oil flux maintain 96.4% and 64,012 L·m-2·h-1, respectively. Furthermore, the magnetic property of these superhydrophobic fabrics could be used in the separation of oil from water. Moreover, the superhydrophobic fabrics possess exceptional self-cleaning performance, mechanical durability, chemical stability, and flame retardancy. These multifunctional superhydrophobic fabrics are potential for wide applications.

Facile preparation of superhydrophobic metal meshes with micro-hierarchical structure via in situ self-assembly metal-organic framework for efficient oil-water separation

Superhydrophobic materials with micro-hierarchical structure are widely in oil-water separation. However, the environmental suitability and stability of material are still a challenge. To overcome this problem, a novel superhydrophobic Cu-MOF based copper mesh was prepared by first using chemical oxidation to obtain Cu(OH)2 nanoarrays on copper substrate, then metal-organic framework (Cu-MOF) crystals were in situ grown using Cu(OH)2 as a sacrificial template, and follow treated with methylpolysiloxane (PDMS). The wetting behavior, surface morphology and physical structure of the modified copper mesh were characterized by the SEM, XRD, FTIR, XPS and WCAs test. The results show that the assembled nanoarrays and deposited crystal particle exhibit a more stable three-dimensional rough structure, which adapted to the harsh oil-water separation environment. The obtained superhydrophobic modified copper mesh (WCA = 156.2°) has a high separation efficiency (96%–99%) and oil flux (2.1–7.3 L m−1 s−1) for different types of oil-water mixtures, and good repeatability. Based on in situ growth strategy and gentle preparation process, the as-prepared functional copper mesh with a low-cost and high-performance has great potential in oil-spill repairment and efficient separation of organic liquids.