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Three-dimensional superhydrophobic/superlipophilic porous materials have attracted widespread attention for use in the separation of oil/water mixtures. However, a simple strategy to prepare superhydrophobic porous materials capable of efficient and continuous separation of immiscible and emulsified oil/water mixtures has not yet been realized. Herein, a superhydrophobic graphene/polystyrene composite material with a micro-nanopore structure was prepared by a single-step reaction through high internal phase emulsion polymerization. Graphene was introduced into the polystyrene-based porous materials to not only enhance the flexibility of the matrix, but also increase the overall hydrophobicity of the composite materials. The resulting as-prepared monoliths had excellent mechanical properties, were superhydrophobic/superoleophilic (water/oil contact angles were 151° and 0°, respectively), and could be used to continuously separate immiscible oil/water mixtures with a separation efficiency that exceeded 99.6%. Due to the size-dependent filtration and the tortuous and lengthy micro-nano permeation paths, our foams were also able to separate surfactant-stabilized water-in-oil microemulsions. This work demonstrates a facile strategy for preparing superhydrophobic foams for the efficient and continuous separation of immiscible and emulsified oil/water mixtures, and the resulting materials have highly promising application potentials in large-scale oily wastewater treatment. [ABSTRACT FROM AUTHOR]

Superhydrophobic polymeric foams, with good thermal stability and high‐recycling capacity to remove oil from oily wastewater, are highly desirable for current oily wastewater purification. Herein, poly (styrene‐acrylic acid 2,2,3,4,4,4‐hexafluoro‐butyl ester‐divinylbenzene) foam with porosity as high as 99.27% has been prepared through high‐internal phase emulsions. Therein, poly (cyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol) microspheres, and Span80 act as co‐emulsifier to stabilize the emulsion system. The as‐prepared foams exhibited super hydrophobicity with a water contact angle of 150.3° and thermal stability. Additionally, the oil adsorption capacity of the porous material could reach up to 25.6–53.4 times its mass with accessible and high‐recycling capacity. These aforementioned outstanding properties make our superhydrophobic foam hold potential applications in oil/water separation. [ABSTRACT FROM AUTHOR]

Superhydrophobic and magnetic materials with multiple functions (e.g., continuous oil collection, remote oil removal in confined spaces under magnetic driven, separation of oil/water emulsions, and good oil absorption capacity with robust stability) are highly required for practical oily wastewater remediation, but still a challenge to be realized. For this purpose, superhydrophobic Fe3O4 nanoparticles/polystyrene (PS) composite sponge has been fabricated via high internal phase emulsion template method. The as-prepared sponge exhibits high water-repellence and superoleophilicity with water/oil contact angles are 155º and 0º, respectively. Given the magnetic properties of Fe3O4, our sponge displays the capacity for remote oil capture under magnetic driven. Additionally, continuous oil collection has been also realized with the equipment of pumper. Different from some previous reported sponges, our sponge also possesses the unique ability to separate surfactant stabilized oil/water emulsion. Besides, our sponge can also act as a high-efficiency oil absorbent with robust cycling stability (oil recovery rate can reach 92%, even after 10 absorption-centrifugation cycles). These outstanding functions make our sponge hold great potential for the purification of oily wastewater. This work reported a simple and environmentally-friendly approach to prepare multi-functional magnetic and superhydrophobic sponges via high internal phase emulsion (HIPE) method. The PS/Fe3O4 composite sponges exhibited unique properties: (i) high water-repellence and good oleophilicity; (ii) the function as a high-efficiency oil absorbent with robust cycling stability; (iii) ability to remove oil remotely under magnetic driven; (iv) continuous oil collection; (v) the capacity to separate surfactant stabilized oil/water emulsion. These outstanding performances make our sponge is of great importance for practical oily wastewater remediation. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials for efficient oil/water separation have significant industrial application value, but their preparation through low-cost and simple strategy is still a great challenge. Herein, melamine foam (MF) was superhydrophobically modified by polydimethylsiloxane (PDMS) through one-pot emulsion polymerization. The nanospheres generated via emulsion polymerization in-situ formed micro-nanostructures on the MF skeleton. During emulsion polymerization, the crosslinking between PDMS was simultaneously carried out to form a hydrophobic layer on the surface of the skeleton. The modified MF was superhydrophobic (the water contact angle and rolling angle were 156.8° and 3°, respectively), had high saturated absorption capacities (61.49–122.73 g/g), and separation efficiency > 99.5% for various oils/organic solvents. Moreover, the foam featured excellent chemical/physical stability, and the surface wettability did not change significantly for acidic (pH = 1), basic (pH = 13), or saturated NaCl solutions or when sonicated. Meanwhile, the foam can continuously separate oil/water mixtures with the assistance of vacuum pump. Furthermore, our foam can also effectively separate the surfactant-stabilized emulsion via simply mechanical compression strategy. These results open an alternative and simple route for treating oily wastewater in practice. [Display omitted] • Foam was superhydrophobically modified by PDMS through one-pot emulsion polymerization. • The foam held excellent stability in corrosive conditions. • The MF@P(St-DVB)/PDMS showed excellent separation performance. • Emulsion separation can be achieved by a simple mechanical compression strategy. [ABSTRACT FROM AUTHOR]

The oil spill and industrial oily wastewater in large quantities has caused severe harm to the environment and human health, which make an urgent requirement to develop low-cost, eco-friendly, stable performance and highly efficient oil/water separation materials. Herein, a superhydrophobic/superlipophilic melamine sponge with excellent hydrophobic stability was successfully fabricated via one-step emulsion polymerization. During polymerization, trimethylolpropane triacrylate (TMPTA) and polyethylene imine (PEI) form robust microspheres, and polydimethylsilane (PDMS) cross-links to form hydrophobic coating on the original sponge skeleton. The modified sponge could continuously separate various immiscible oil/water mixtures under harsh conditions (including strong acids, strong bases, salts). Even after 10 consecutive cycles, the separation efficiency for toluene and petroleum ether exceeds 99.87%. In addition, the as-prepared sponge exhibited extraordinarily high oil absorption capacities (with a maximum saturated oil absorption of 107.31 g/g for chloroform) and excellent reversible compressibility (up to 100 compression cycles). More importantly, the pore size of modified sponge was adjusted through a simple mechanical compression strategy so that the compressed sponge met the particle size screening requirements to effectively separate the surfactant-stabilized water-in-oil emulsions. Based on the simple preparation protocol, fluorine-free raw materials, and excellent properties, the MS-TMPTA/PEI-PDMS sponge presented here have extremely promising application potential in oil/water separation. [Display omitted] • Sponge was superhydrophobically modified via one-pot emulsion polymerization. • The MS-T/PEI-PD sponge exhibited excellent mechanical/thermal/chemical stability. • Modified sponge could continuously and efficiently separate oily wastewater. • Emulsion separation could be achieved by simple mechanical compression strategy. [ABSTRACT FROM AUTHOR]