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Porous materials with excellent mechanical stability and robust superhydrophobic performance exhibit promising prospect for practical applications in the field of oil−water separation. The construction of superhydrophobic surfaces typically involve two individual steps, including increase surface roughness and decrease surface energy. Unlike traditionally approach, the superhydrophobic performance of modified PU sponge can be accomplished by one−pot approach, which does not require complicated processing procedures or specific equipment. The present study successfully developed a superhydrophobic porous PU sponge using a facile and cost−effective one−pot approach by employing tannic acid (TA), 3–aminopropyltriethoxysilane (APTES), and octadecyltrimethoxysilane (ODTS) as superhydrophobic modifiers. The water contact angle of the modified PU sponge was determined approximately 152.3 °, suggesting its superhydrophobic characteristic. The modified PU sponge showed remarkable environmental tolerance when subjected to a wide pH range of acidic and alkaline solutions. The WCAs remained consistently above 150°, indicating its durability and stability against harsh circumstances. The superhydrophobic PU sponge also demonstrated remarkable of self−cleaning and antifouling capacities. The obtained sponge exhibited an impressive selective oil adsorption capacity from oil−water mixtures, ranging from 18.7 to 88.4 times of its initial mass, depending on the specific type of oil utilized in the test. The sponge still maintained its excellent adsorption capacity even after 20 cycles of adsorption–squeezing experiment. Immiscible oil−water mixtures with different densities could also be highly effectively separated by the superhydrophobic PU sponge in a continuous way. The separation efficiencies for diesel/water and chloroform/water were determined to be 98.5 % and 99.5 %, respectively, demonstrating outstanding levels of continuous separation effectiveness. With the readily available PU sponge as substrate material and the simple modification process, this work could provide a potential pathway for fabrication of cost−effective, long durable, and high efficient superhydrophobic materials in oil/water separation. • A facile one−pot approach was applied to fabricate durable superhydrophobic PU sponge. • The modified PU sponge showed environmental tolerance when subjected to different acidic and alkaline solutions. • The modified PU sponge exhibited an impressive selective oil adsorption capacity from oil−water mixtures. • The oil−water mixtures with different densities could be separated by the modified PU sponge in a continuous way. [ABSTRACT FROM AUTHOR]

The Dy-MOF@PU sponge can successfully carry out oil–water separation and W/O emulsion separation. To intuitively reveal the separation mechanism of the Dy-MOF@PU sponge for the emulsion, a hypothetical separation process was made. [Display omitted] • Lanthanum-based Dy-MOF was used to decorate 3D PU sponge. • Dy-MOF-F@PU sponge was successfully synthesized by a simple sedimentation method. • Explore the effect of method synthesis on the morphology and hydrophobicity. • Modified sponge with excellent mechanical flexibility, durability and repeatability. Leakage of industrial oil and organic solvents seriously harms environment and ecology yet demanding highly efficient and durable materials for oil–water separations. In this work, ultra-light and highly flexible polyurethane (PU) sponges were engineered to 3D oil–water separators by coating the dysprosium metal organic framework (Dy-MOF) onto the surfaces of the PU frames. Through a facile impregnation, the Dy-MOF was attached to the full frames of the sponges. Consequently, liquid contact surfaces were extended from these on top layers to the whole rack. Superhydrophobicity with water contact angles up to 152.08° and lipophilicity enable continuous separations of dichloromethane from water through the resulted Dy-MOF@PU sponges in a continuous mode. The modified sponges own high gravimetric absorption capacities for oil and organic solvents, and high resistances to temperature variations, corrosive solutions, and mechanical abrasions, thanks to the well-connected and stable superhydrophobic/supportive interfaces. An efficient separation was successfully piloted for oily wastewater consisting of water-in-oil emulsions stabilized by surfactants, demonstrating the potential of practical water treatment of Dy-MOF@PU in complex environments. Mechanism leading to superior oil–water separation capability was studied and inferred as the combined effects of the physical and chemical properties arisen from the stable Dy-MOF and flexible but porous matrix. [ABSTRACT FROM AUTHOR]

Common separation materials are divided into two-dimensional (2D) materials and three-dimensional (3D) materials, among which three-dimensional materials have excellent durability and stability. Herein, we developed a durable S@P@PU sponge by simply immersing polyurethane (PU) sponges in a blending solution of starch granules and polydimethylsiloxane (PDMS). Blending starch granules and PDMS could achieve more reliable adhesion of starch granules to the PU sponge by utilizing the high adhesion of PDMS. At the same time, the presence of starch granules could make PDMS form a spot-like secondary structure on the sponge. The sponge exhibited excellent hydrophobicity and high organic solvent affinity, and could separate and absorb organic solvents from the turbulent flow. The results showed that the sponge could absorb and hold 46 times its organic solvent weight, with a separation efficiency greater than 98.5% for different organic solvents. In addition, the sponge maintained a water contact angle of more than 140° after 40 abrasion cycles or after immersion in different pH and salt solutions for 48 h, showing excellent mechanical durability and chemical stability. [Display omitted] • The modified sponge water contact angle is increased from 86° to 157°. • In extreme environments, sponges still have water contact angles of >140°. • The separation efficiency of the modified sponge is greater than 99%. • The modified sponge can hold 46 times its own weight of organic solvent. • The sponge has the advantages of low cost and short time consumption. [ABSTRACT FROM AUTHOR]

The influence of different coupling agents and coupling times on the wettability of a polyurethane (PU) sponge surface were optimized. Octadecyltrichlorosilane (OTS) was selected as the optimal coupling agent to prepare the superhydrophobic sponge. The superhydrophobic sponge was prepared in one step, which has the advantages of simple operation and enhanced durability. The superhydrophobic sponge was characterized by scanning electron microscopy, Teclis Tracker tensiometry, and Fourier transform infrared (FT-IR) spectrophotometry. The water contact angle increased from 64.1° to 151.3°, exhibiting ideal superhydrophobicity. Oils and organic solvents with different viscosities and densities can be rapidly and selectively absorbed by superhydrophobic sponges, with an absorption capacity of 14.99 to 86.53 times the weight of the sponge itself, without absorbing any water. Since temperature affects the viscosity and ionic strength of oil, and influences the surface wettability of the sponges, the effect of temperature and ionic strength on the oil absorption capacity of the superhydrophobic sponges was measured, and its mechanism was elucidated. The results showed that the absorptive capacity retained more than 90% of the initial absorptive capacity after repeated use for 10 times. Low-cost, durable superhydrophobic sponges show great potential for large-scale oil-water separation. [ABSTRACT FROM AUTHOR]

The oil spill and the illegal discharge of organic solvents not only cause the waste of resources but also damage to the ecological environment, so it is very important to deal with it immediately. In this paper, the natural sepiolite（SEP） was modified by vinyltriethoxysilane(VTES) and 3-chloropropyltriethoxysilane(CTES) to gain excellent hydrophobicity. Then the modified superhydrophobic sepiolite（MSEP） powder was loaded onto the three-dimensional polyurethane(PU) sponge by repetitive dipping and drying. The water contact angle of MSEP@PUsponge reached 155°, and its adsorption capacity for various oils and organic solvents was 26–71 times higher than its own weight. After 15 cycles of squeeze-adsorption, the adsorption capacity of MSEP@PUsponge just decreased slightly for n-hexane, rice oil, diesel oil and chloroform. Moreover, after continuous separation of the diesel and water mixture for 10 times, MSEP@PUsponge still showed hydrophobicity. At the same time, the prepared sponges showed excellent stability under extreme environment and good mechanical property after 200 compression cycles. [Display omitted] [ABSTRACT FROM AUTHOR]