Superhydrophobic Sponge Research Articles

Magnetic superhydrophobic sponge with 3D interpenetrating network structure coating for multimodal driven oil/water separation

In this paper, a simple dipping technique was employed to construct a 3D interpenetrating network structure coating, which was used to prepare a robust, superhydrophobic and magnetic sponge. The modified sponge exhibits rapid adsorption behavior, high adsorption capacity (up to 60–159 times its own dry weight or above 119 %–186 % of its own volume for various oils/organic solvents), stable superhydrophobicity and reusability. After 100 times extrusion adsorption test, it retains 70 % adsorption capacity and the WCA is still over 140°. More importantly, the modified sponge presents excellent robustness and chemical stability after a long time of chemical reagent treatment (HCl, KOH, NaCl) and mechanical friction test 1000 cycles. Notably, the magnet, pump, self-adsorption, gravity and solar-driven oil/water separation devices based on the modified sponge also were applied, particularly the separation of crude oil mixtures via the solar-driven mode, demonstrating the broad prospects of such modified sponges in actual applications. As such, this study not only provides an environmentally friendly, efficient, robust and low-cost design strategy for multi-state oil spill cleaning, but also focuses on solving the problem of material recovery and the use of materials in harsh environment.

Engineering green MOF-based superhydrophobic sponge for efficiently synchronous removal of microplastics and pesticides from high-salinity water.

Microplastics (MPs) and pesticides are becoming an intractable environmental issue due to their wide spreading and non-degradable nature, posing serious threat to ecosystem and human health. To settle such dilemma, this work reasonably designed a superhydrophobic MOF-based coated sponge (ODSOSS/TiO2/Ni-MOF/PDA@Sponge) through the combination of an environmentally friendly in-situ supersaturated coprecipitation and polysesiloxane modification method. Among them, (I) the introduction of polydopamine (PDA) not only improves the adhesion between coatings and sponge, but also enhances the growth of MOF structure through complexation. (II) The obtained Ni-MOF shows large-area microscale anthemy structure with multilayered flaky texture, forming heterogeneously hierarchical structure with the deposited TiO2 nanoparticles, which promotes photodegradation ability of TiO2 owing to great specific surface area of Ni-MOF. (III) The high specific large area Ni-MOF supplies sufficient action sites for linkage of PDA and polysesiloxane molecules with unique nanocage-like structure, thus further greatly increasing adsorption force for various pollutants. (IV) The superhydrophobicity protect the porous channels of MOF from contamination of various absorbed pollutants, while TiO2 nanoparticles effectively photodegrade the absorbed organic pollutants, endowing the sponge superior recyclability. The superhydrophobic sponge selectively rapidly and synchronously adsorbs various MPs (maintained almost 100% after 60 cycles) and pesticides (adsorption rates 71.6%-95.1%) from high-salinity water. The large-area sponge (9cm×6cm×1cm) simultaneously removes almost 100% MPs (40mg/L), Sudan Ⅲ (10mg/L), kerosene (30mL/L), and four pesticides (10mg/L) within 1min. Particularly, four pesticides are quickly photocatalytic degraded by the coated sponge. The free radical capture trials show that hydroxyl radicals (·OH) are the main active species of pesticide degradation. Furthermore, we reveal the negative centers where pesticide molecules are most vulnerable to ·OH attack, on basis of the charge distribution and molecular electrostatic potential (MEP) analysis. The adsorption mechanisms are carefully clarified through theoretical calculation and experimental data. This work not only provide an effective superhydrophobic candidate for MPs and pesticides removal in a broad applicable scope (especially in high-salinity wastewater), but also opens a new strategy for environmental remediation.

Light-Propelled Super-Hydrophobic Sponge Motor and its Application in Oil-Water Separation.

Self-propelled separation materials, that is, motor, are one of the keys to realizing smart oil-water separation. Although three-dimensional sponges such as commercial melamine sponge (MS) exhibit excellent oil-water separation ability, they cannot move by themselves on water. Aiming at solving this problem, a polydimethylsiloxane (PDMS) and molybdenum disulfide (MoS2) modified MS motor (PDMS@MS/MoS2) with an asymmetric multilayer structure was prepared, in which the photothermal layer MoS2 provided the propelling force for the motor under infrared light irradiation, and the middle layer PDMS was used as the superhydrophobic modified agent and adhesive agent between commercial MS and MoS2 powder. PDMS coated MS (PDMS@MS) as the superhydrophobic layer showed good superhydrophobic ability (153.1°) and oil-water separation capacity (52.33 g/g to liquid paraffin). Furthermore, the introduction of MoS2 made the speed of the sponge motor reach 8.27 mm s-1 with a removal quantity of 12.20 g/g for cyclohexane. After recycling 8 times, the contact angle, cyclohexane capturing amount, and average velocity of the motor were 150.3°, 11.40 g/g, and 8.41 mm/s, respectively. Meanwhile, PDMS@MS/MoS2 kept a similar light-propelling velocity (∼8 mm) at different pH values and in simulated seawater, demonstrating that the light-propelling motor possessed a good cycle and practical performance, which provides a possibility for the directional light propulsion of a sponge motor in oil-water separation.

Preparation of superhydrophobic sponge and its application in oil-water separation and treatment of polymer-containing wastewater.

At present, the application prospect of superhydrophobic materials in oil-water separation, an-tibacterial and other aspects have attracted more and more attention. However, preparing a simple and low-cost superhydrophobic material remains a challenge. Using acetone as solvent, candle soot, silver/silica nanoparticles and polydimethylsiloxane were uniformly mixed to form a mixed solution, and the superhydrophobic sponge was successfully prepared by spraying method. The results show that the superhydrophobic sponge has high water contact Angle (162°) and excellent oil-water separation efficiency, which can realize effective treatment of polymerized wastewater. In addition, the superhydrophobic sponge showed better antibacterial properties on the surface of Escherichia coli and Staphylococcus aureus. In this work, a simple way to prepare superhydro-phobic oil-water separation material is proposed. The preparation process is green, the material is easy to obtain, and it is expected to be widely used in practical production.

Photo/electro-thermal effect, flame retardant, multifunctional durable superhydrophobic sponge for all-weather recovery high viscosity crude oil and photothermal defrosting/deicing

Developing functional adsorption materials that efficiently adsorb high viscosity oil is crucial for solving oil spill accidents. Herein, low-density three-dimensional porous melamine sponge was used as the modified substrate. First, phytic acid is selected for modification to make it flame retardant. Then, polypyrrole (PPy) and hexadecyltrimethoxysilane (HDTMS) are modified on its surface through low-temperature polymerization and impregnation, ultimately obtaining a multifunctional durable superhydrophobic PA/PPy/HDTMS@MF (melamine foam) sponges with photo/electro-thermal effects and flame retardant. When the applied voltage is 10 V, the core temperature on the PA/PPy/HDTMS@MF sponge’s surface rapidly increases from 26.4 °C to 134.6 °C within 80 s, and the sponge will not burn and be damaged. Under the irradiation of one sunlight (1 kW/m2), the surface core temperature can rapidly rise from 26.4 °C to 93 °C within 70 s. The superhydrophobic PA/PPy/HDTMS@MF sponge can all-weather absorb kinds of high viscosity crude oil and solid oils that are 18–27 times than its own mass, indicating that the prepared superhydrophobic sponge has excellent oil collection performance. And under one sunlight (1 kW/m2), after 10 cycles of desorption, the prepared superhydrophobic sponge can still absorb 26 times more crude oil than its own weight. In addition, PA/PPy/HDTMS@MF sponge also has the characteristic of photothermal defrosting and deicing, and the ice on its surface can begin to melt within 5 min under one sunlight (1 kW/m2). The melted water will not enter the inside of the sponge, effectively ensuring the utilization efficiency of photothermal effects. Based on the above advantages, the prepared photo/electro thermal conversion superhydrophobic sponge has excellent development prospects in the field of high viscosity oil adsorption and photothermal defrosting/deicing.

Facile fabrication of robust superhydrophobic polyurethane sponge modified with polydopamine- silica nanoparticle for effective oil/water separation

Porous superhydrophobic materials with high mechanical stability have a significant amount of potential for oil-water separation in practice. In this study, a superhydrophobic material with strong hydrophobic coating adhesion was developed using a polyurethane sponge. The interior and exterior surfaces of the porous polyurethane material were coated using a two-step technique. The sponge was treated with poly (dopamine) to modify its skeleton, allowing the second layer to adhere readily. The second layer of silica applied to the surface of the sponge functions as a superhydrophobic layer. The modified sponge's water contact angle was approximately 156.2° ± 5°, compared to 78° ±2° for the original sponge, demonstrating its superhydrophobic nature. The fabricated sponge is capable of separating and absorbing 43.3–51 times of its initial mass from an oil-water mixture, depending on the type of oil used in the test. Fifteen cycles of oil-water separation were followed by chemical cleaning of the hydrophobic sponge. After undergoing these cycles, the hydrophobic nature and absorption capacity of the produced sponge were preserved. Over a broad pH range, the hydrophobicity of the superhydrophobic sponge was studied, and the results indicated that hydrophobicity was substantially maintained even under harsh pH operating conditions. The water contact angle of the sponge was measured to be 145° ± 1° and 140° ± 1°, respectively, after 12 h of immersion in strong acids and bases.

Loofah plant—Derived biodegradable superhydrophobic sponge for effective removal of oil and microplastic from water

Recently, oil spills and microplastic have become vital worldwide environmental issues. In this study, inspired by the natural phenomenon, two types of biodegradable superhydrophobic sponges derived from the loofah plant were fabricated to deal with those contaminants. Loofah is a niche vegetable for food and eco-sponges and is very popular in Europe and Asia. A facile fabrication process is carried out with dip-coating techniques, which help to functionalize the surface of the natural loofah sponge with two types of natural wax (bee wax and palm wax). The fabricated materials named LS-B(2) and LS-P(2) showed excellent superhydrophobicity with a high water contact angle, which was fundamental for separating oil in the water mixture and capturing microplastics. The derived superhydrophobic sponges displayed a high oil absorption capacity in the range of 72–81 g g−1 for LS-B(2) and LS-P(2). The separation efficiency reached over 99 % for the immiscible kerosene/water mixture and the fabricated material’s excellent recyclability via simple squeezing. The sponges also can capture the microplastics at different concentrations with very high adsorption capacity (381–569 mg/g), reaching over 99% polystyrene microplastics from aqueous suspensions under continuous stirring conditions. With the natural abundance of the base material in nature and the ease of the fabrication process, this work could open the novel direction for a low-cost, high-performance, and large-scale application material in the future toward environmental sustainability.

Superhydrophobic Sponge for Highly Efficient Separation of Both Stratified and Emulsified Oil–Water Mixtures

Efficient separation of oil–water mixtures, particularly homogeneous and stable emulsions, has always been an industrial challenge. Herein, we report a facile, cost-effective procedure for fabricating superhydrophobic melamine sponges using a single solution–immersion process. The modified sponge has stable superhydrophobicity owing to the synergy of triple hydrophobic mechanisms with a maximum water contact angle of 158°. As an absorbent, the modified sponge block exhibits high porosity, outstanding absorption capacity, excellent mechanical properties, and superior physical and chemical stability, enabling its use for the separation of stratified oil–water mixtures via repeated absorption–extrusion processes with a separation efficiency of nearly 100%. Furthermore, as a filter, the crushed, modified sponge powders exhibit a demulsification efficiency ranging from 97.65 to 99.33% for the separation of ideal water-in-oil emulsions under gravity. Finally, the feasibility of these sponges for oilfield applications is established through the demonstration of the continuous separation of an emulsion of brine in crude oil using the modified sponge powders in conjunction with an in-house built apparatus. This work may open a viable pathway for the efficient separation of both stratified and emulsified oil–water mixtures via wettability, and provide a novel strategy for the reuse of waste sponges.

Self-stratifying coating enables facile fabrication of robust superhydrophobic sponges for oil-water mixture separation

Superhydrophobic polymer sponges are a promising solution to the serious environmental crisis caused by oil spills in modern society, given their excellent sorption capacity and high selectivity, if designed well. However, realizing such hydrophobic sponges in an eco-friendly, easy, and cost-effective way is still a challenging task, despite several reported methods. Here, we report a facile approach to obtaining a superhydrophobic sponge using self-stratifying coating technology. The process briefly involves dip coating a pre-made commercial sponge in our prepared self-stratifying resin, followed by curing. The prepared superhydrophobic sponges showed excellent oil sorption capacity towards various organic solvents, with adsorptive capacity values ranging from ∼100 to 200 g/g and the capability to be reused >20 times with an adsorption retention capacity of above 95 % of the first cycle. In addition, the modified sponge presented good mechanical stability and thermal stability (up to 350 °C). With the advantages of the fabrication method and the benefits in oil-water separation, the modified sponge has promising applications in the field of oil spill treatment and environmental remediation.

Surface fabrication of silica aerogels from inorganic precursor achieving elastic and superhydrophobic sponges for oil-water separation

Some challenges exist in oil-water separation materials, including complex synthesis, high preparation costs, and weak recovery. Herein, the elastic and superhydrophobic silica aerogels/polyurethane sponges (SA/PUS) were prepared by fabricating silica aerogels (SA) on the skeleton of the cheap polyurethane sponges (PUS), through a simple dipping and sol-gel method under ambient pressure drying procedure. Importantly, boosted by the inorganic silicon precursors, the dense and rough coating by the functionalized SA on the surface was realized under environmentally friendly modification and adhesive-free, which contributed to the superhydrophobicity of the SA/PUS. The splendid thermal stability allowed the SA/PUS to maintain a hydrophobic property at high temperatures (over the flash point of the oil in this work). The excellent adsorption performance was confirmed on both oil/water mixture (11 times own weight) and oil-in-water emulsion (separation efficiency up to 98.78%). Moreover, the elastic SA/PUS could recover from large-scale deformations owing to the combination with the PUS with a three-dimensional skeleton, which improved the mechanical strength and overcome the limitation of the brittle SA. The recovery efficiency of the adsorbed oil from oil/water mixture was 92.70% and nearly no decline in reusing by simple mechanical squeezing. Such excellent performance was also demonstrated in oil-in-water emulsion. Advantages (superhydrophobic and lipophilic, elastic, and thermal stability, etc.) of the SA/PUS, which were prepared by simple synthesis, bring application potential for treating automobile maintenance sewages and expanded applications, including separation and recovery of oil from oily wastewater circularly and uptake of high-value-added hydrophobic molecules in biomass or other processes.

Superhydrophobic magnetic Fe3O4 polyurethane sponges for oil–water separation and oil-spill recovery

The effective and affordable separation of oil and water, a crucial process in the safe handling of environmental disasters such as crude oil spills and recovery of valuable resources, is a highly sought-after yet challenging task. Herein, superhydrophobic PU sponge was fabricated for the fast and cost-effective adsorptive separation of oil and different organic solvents from water. Octadecyltrichlorosilane (OTS)-functionalized Fe3O4@SiO2 core–shell microspheres were dip-coated on the surface of porous materials via a dip-coating process, thereby endowing them with superhydrophobicity. Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores, the resulting superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil–water mixtures, including oil–water suspensions and emulsions. Remarkably, after the recovery of the adsorbed oil via mechanical extrusion, these superhydrophobic materials could be reused multiple times and maintain their oil–water separation efficacy even after 10 oil–water separation cycles.

Scalable manufacturing of nonflammable bioinspired superhydrophobic sponge for oily wastewater treatment via water-based strategy

Developing a water-based methodology for scalable-manufacturing the versatile sponge materials, is meaningful but highly challenging. In this work, a superhydrophobic sponge was constructed via a simple and green strategy, which contained melamine sponge (MS) substrate, polydopamine (PDA) and hydrophobic SiO2 (HSiO2). Prominently, the aqueous solvent is harmless to the various sponge materials, in which superhydrophobic HSiO2-PDA@MS (SPMS) inherited the nature of MS, including excellent oil-uptake (67.6–139.1 times of its weight), superior mechanical property, porous structure and flame retardancy. The layer of HSiO2/PDA not only endowed the SPMS selective sorption ability, but also showed a good interfacial compatible to further improve the flame-retardant property for MS or ignitable polymer sponge. Thus, SPMS exhibited a good adaptability in fire, could significantly reduce the fire risks in oil spill accident and achieve the fire-off through a simple press procedure. Moreover, the compressed SPMS showed the satisfactory separation efficiency (over 99 %) for surfactant-stable O/W emulsions, even in separating complex O/W emulsions (SE over 96 %). And this sponge displayed excellent robust durability, outstanding recyclability. Given about all, this work provides a novel inspired insight for the large-scale design of multifunctional sponge material for oily wastewater treatment.

Superhydrophobic sponge with nanoneedle-like surface for efficiently separating immiscible and emulsified oil-water mixtures

To increase the collision probability between emulsified droplets and sponge surface for more efficient separation of emulsions, a durable superhydrophobic melamine sponge (MS) with nanoneedle-like surface was prepared through a simple and inexpensive route in this work. The fabrication processes included the formation of ZnO nanoneedles on MS surface via a hydrothermal method, followed by coating with polybenzoxazine based bisphenol A and dodecylamine (PB-D). As excepted, the resulting superhydrophobic sponge (PB-D/ZnO/MS) could effectively separate various surfactant-stabilized water-in-oil and oil-in-water emulsions, with a high permeation flux of up to 14,050 L m−2 h−1 and separation efficiency above 98.5 %, driven solely by gravity due to its nanoneedle-like surface. Moreover, PB-D/ZnO/MS also displayed outstanding absorption capacities for various oils and organic solvents (57.4–123.0 g/g) as well as prominent reusability, enduring 30 cycles of repeated absorption-squeezing without any evident decrease in water contact angle and absorption capacity (maintaining 90.9–96.6 % of initial value). In addition, the superhydrophobicity of PB-D/ZnO/MS remained almost unchanged after being immersed in strong acidic, alkaline and salty solutions for 48 h. Furthermore, PB-D/ZnO/MS not only showed outstanding flame retardancy but also remained rapid oil absorption rate under combustion conditions. Thus, the obtained superhydrophobic MS is a promising candidate for practical oil/water separation.

Environment-Friendly superhydrophobic sponge for highly efficient Oil/Water separation and microplastic removal

The pollution of water resources by oils and microplastics is a significant global issue affecting the environment and human health. However, developing a sustainable multifunctional adsorption material to remove multiple pollutants has always been a challenge. Herein, an eco-friendly superhydrophobic polyurethane sponge was developed using polydimethylsiloxane (PDMS) and dehydroabietic acid grafted Al2O3 nanoparticles by dip-coating technique. The green dehydroabietic acid has strong hydrophobicity, which can make the coated sponge have excellent separation of oil/water mixtures or emulsions and has a high oil absorption capacity (20–55 g/g) for various kinds of oils. Continuous oil/water separation was also achieved by gravity-driven or with the assistance of peristaltic pump. After 10 separation cycles, the coated sponge still exhibits excellent separation efficiency (greater than 97%) due to its outstanding mechanical durability and compressive performance. Moreover, various kinds of microplastics could be efficient captured from the aqueous solution at a higher rate using the coated sponge, which is mainly due to the capillary force of the coated sponge and the non-covalent force and conjugates between PDMS and microplastics. This work provides a new strategy to fabricate a sustainable multifunctional sponge for oily wastewater and microplastics and shows the great potential for large-scale practical application.

Fabrication of eco-friendly Cu/Co-LDHs-based superhydrophobic sponge and efficiently synchronous removal of microplastic, dyestuff, and oil

Fabrication of eco-friendly Cu/Co-LDHs-based superhydrophobic sponge and efficiently synchronous removal of microplastic, dyestuff, and oil

Scalable Fabrication of Superhydrophobic Coating with Rough Coral Reef-Like Structures for Efficient Self-Cleaning and Oil-Water Separation: An Experimental and Molecular Dynamics Simulation Study.

Superhydrophobic coating has a great application prospect in self-cleaning and oil-water separation but remains challenging for large-scale preparation of robust and weather-resistant superhydrophobic coatings via facile approaches. Herein, this work reports a scalable fabrication of weather-resistant superhydrophobic coating with multiscale rough coral reef-like structures by spraying the suspension containing superhydrophobic silica nanoparticles and industrial coating varnish on various substrates. The coral reef-like structures effectively improves the surface roughness and abrasion resistance. Rapid aging experiments (3000h) and the outdoor building project application (3000 m2 ) show that the sprayed superhydrophobic coating exhibits excellent self-cleaning properties, weather resistance, and environmental adaptability. Moreover, the combined silica-coating varnish-polyurethane (CSCP) superhydrophobic sponge exhibits exceptional oil-water separation capabilities, selectively absorbing the oils from water up to 39 times of its own weight. Furthermore, the molecular dynamics (MD) simulation reveals that the combined effect of higher surface roughness, smaller diffusion coefficient of water molecules, and weaker electrostatic interactions between water and the surface jointly determines the superhydrophobicity of the prepared coating. This work deepens the understanding of the anti-wetting mechanism of superhydrophobic surfaces from the perspective of energetic and kinetic properties, thereby paving the way for the rational design of superhydrophobic materials and their large-scale applications.

Versatile superhydrophobic sponge for separating both emulsions and immiscible oil/water mixtures

Much effort in resource recycling and recovery has been devoted to developing durable materials for separation, but their versatility for emulsions and immiscible oil/water mixtures was far from ideal. In this work, a superhydrophobic sponge (MS-EP-APT) was developed using asphaltene (APT), melamine sponges (MS) and polyethyleneimine (PEI) for demulsification and water-oil mixture separation. These three easily obtained materials came from either oil refinement residue or low cost chemicals. The surface wettability, chemical stability, and mechanical durability of the sponge were analyzed to determine its separation potential. This sponge exhibited great separation efficiency for immiscible oil/water mixtures (> 96.0%), surfactant stabilized water-in-oil (W/O) emulsions (> 96.0%) and anionic surfactant-stabilized oil-in-water (O/W) emulsions (> 98.0%). It demonstrated good reusability and salt tolerance even in seawater. The separation mechanisms were proposed to be related to the hydrophobicity, positive charge, and torturous channels of the sponge. These superior performances make our sponge a strong candidate for green manufacturing and engineering in resource recovery and environmental remediation.

Novel Collection Equipment Loaded with Superhydrophobic Sponge for Continuous Oil/Water Separation from Offshore Environments

Currently, frequent oil spill accidents caused by transportation, storage, and usage may lead to extensive damage to marine ecosystems. Effective methods for oil spillage recovery from offshore environments are still urgently in demand. A superhydrophobic sponge (MS@PVC@SiO2) was obtained via a facile two-step method for rapid oil adsorption, and a piece of novel collection equipment loaded with MS@PVC@SiO2 was developed for in situ continuous oil/seawater separation. The results showed that MS@PVC@SiO2 exhibits excellent water repellence, compressibility, and durability. Furthermore, the obtained MS@PVC@SiO2 shows high diesel oil adsorption capacity (32 g/g), and excellent recyclability (up to 200 times). The collection equipment demonstrates highly selective oil adsorption capacity and good stability in real seawater. The maximum possible recovery capacity of collection equipment was 557.784 L/h with 98% efficiency, which was much higher than that of commercial disc oil collectors (119.8 L/h). The recovery performance was effectively improved by introducing MS@PVC@SiO2, due to its large specific area and enough storage space. Moreover, even after continuous operation for 58 h in seawater, the collection equipment remained at a high recovery capacity. The results indicate that both MS@PVC@SiO2 and the collection equipment have great application perspectives in practical marine oil spillage recovery.

Superhydrophobic DTMS/rGO-nanocomposites modified polyurethane sponge for efficient oil–water separation

ABSTRACT Dodecyltrimethoxysilane (DTMS)-modified reduced graphene oxide (rGO) nanocomposites were incorporated into polyurethane (PU) sponges by a combination of dip-coating and thermal curing reduction reaction to obtain a novel superhydrophobic DTMS-rGO-PU sponge for effective oil/water separation. The reaction conditions, such as the dip-coating solution concentration, the thermal curing reduction temperature, and the reaction time were demonstrated to be key factors in forming hierarchical DTMS-rGO nanocomposites, which significantly affected the surface wettability of the PU sponge. The resulting DTMS-rGO-PU sponge with a static water contact angle (WCA) of 152.2° displayed superior superhydrophobicity, and achieved an oil–water separation efficiency of 99.89% for various oil/water mixtures. This superhydrophobic sponge also showed minimal deterioration in its high oil adsorption capacity after 100 recycled adsorption operations. Furthermore, the as-prepared DTMS-rGO-PU sponge was proven to be physically and chemically stable and durable in harsh environmental conditions, suggesting its potential for industrial applications in oil spillage management.

The superhydrophobic sponge decorated with Ni-Co double layered oxides with thiol modification for continuous oil/water separation

In this paper, the superhydrophobic polyurethane sponge (SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides (LDOs) on the surface, and following modification with n -dodecyl mercaptan (DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultra-low adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability. Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.