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Marine mussel-inspired polydopamine (PDA) coatings show excellent hydrophilicity and substrate-independent adhesion ability, but low stability, especially in a harsh environment such as strong acid or strong base, significantly restricts their applications. In this work, we prepare a novel superhydrophilic and underwater superoleophobic coating based on a modified PDA. Diglycidyl resorcinol ether (DGRE) polyethyleneimine (PEI) and iron ions were incorporated into PDA to strengthen the cross-linking and coating durability. By using three chemically inert hydrophobic membranes, polytetrafluoroethylene (PTFE), poly(vinylidene fluoride), and polypropylene, as substrates, we showed that PDA/PEI/DGRE-coated membranes had a water contact angle (CA) of 0° and underwater oil CA above 157°, and their underwater oil SAs were <7°. The coating is durable against both physical and chemical damages including ultrasound and heat treatments, as well as acid/alkaline etching. After ultrasound treatment in water for 60 min, and heating treatment for 3 h, or acid/alkaline etching for 3 h, the coated PTFE membrane still showed water CAs of ∼0° in air and underwater oil CAs of ∼150°. The coated membranes can efficiently separate oil-in-water emulsions, even in strong acid and base environments. The water flux was above 1500 L m−2 h−1, and the oil rejection was above 99%. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy has been developed to fabricate phase change fibers. • The resulting fibers exhibited excellent flexibility, stretchability and elasticity. • The fibers showed reduced octadecane leakage, extremely high heat capacity and reusability. Although phase change fibers have proven to be highly potential for a variety of applications, the rigidity of solid–liquid phase change material in its solid state hinders the fabrication of highly stretchable phase change fibers. In this work, we report a strategy of encapsulating phase change material (octadecane, OD) in thermoplastic polyurethane (TPU) based on a nonaqueous emulsion (OD-in-TPU solution), which serves as the core layer liquid in coaxial wet spinning. The use of TPU solution as the outer layer liquid provides an extra cover for the core layer of TPU dispersed with OD. The resulting core-sheath structured phase change fibers exhibited excellent flexibility, stretchability and elasticity, with the tensile strain at break up to 623.9 % and ultimate stress up to 3.5 MPa. The fibers showed heat absorption and release temperatures ranging from 30.7 to 32.0 °C and from 21.6 to 22.3 °C, respectively, similar to that of bulk OD. In particular, the fibers possessed much reduced OD leakage in comparison to fibers from conventional methods, and the fibers exhibited extremely high heat capacity (up to 187.8 J/g), without obvious deterioration observed in heat capacity after 100 heating–cooling cycles. Simple fabrication, excellent stretchability, high heat capacity, and reusability enabled such phase change fibers to be highly promising for practical use in temperature regulation. [ABSTRACT FROM AUTHOR]

Although amphiphilicity is an integral component for the applications of polyHIPEs (PHs), it is challenging to produce hydrophobic PHs from hydrophilic monomers. Herein, hydrophobic polyurethane (PU) PHs have been fabricated from a water‐soluble mannitol within block copolymer surfactant‐stabilized, nonaqueous high internal phase emulsions (HIPEs). These highly porous, interconnected, macroporous PU PHs were hydrophobic with water contact angles between 102° and 140°, demonstrating that water‐soluble monomers could be used for fabrication of hydrophobic PHs. The block copolymer surfactant acted not only as the HIPE stabilizer, but also as a monomer, enhancing hydrophobicity and overcoming some drawbacks imposed by conventional inert stabilizers. The solvents used for PU PH synthesis and purification were easily recovered and reused, showing that nonaqueous HIPE templating for PU PH preparation is an efficient and facile route. The PU PHs were investigated for oil spill reclamation and they were demonstrated to be an ideal candidate for such an application. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1315–1321 [ABSTRACT FROM AUTHOR]

Emulsion-templated, hydrophilic-oleophobic porous materials are promising for various applications, but their relatively weak mechanical properties of the resulting materials hinder them from real applications. Herein, we report the fabrication of emulsion-templated, hydrophilic and underwater oleophobic poly(vinyl alcohol) aerogels with enhanced mechanical property, bereft of the use of fluorine-containing components. The resulting aerogels exhibited flexibility, compression and stretchability both in dry and in wet states, showing enhanced compressive and tensile performances. The hydrophilicity and underwater oleophobicity enabled the pre-wet aerogels to have anti-fouling property and suitable for removing water from oil-water mixtures and surfactant-stabilized, water-in-oil emulsions. Taking their advantageous wettability, the aerogels were studied for solar steam evaporation from oil-containing salt aqueous solution after coating a thin layer of carbon nanotubes at the top. The evaporators showed high water evaporation rate (up to 2.7 kg m−2 h−1), high light-to-thermal conversion efficiency (up to 99%) and excellent continuous evaporation rate at 2.1 kg m−2 h−1 after 10 h′ continuous evaporation. The hydrophilicity, underwater oleophobicity and enhanced mechanical properties enabled the PVA aerogels as good candidates for removing water from various oil-water mixtures and for preparing solar steam evaporators. [Display omitted] • Hydrophilic and underwater oleophobic PVA aerogels were obtained from emulsion templating. • The aerogels exhibited flexibility, robust compression and stretchability. • The pre-wet aerogels could remove water from oil-water mixtures (emulsions). • The aerogels served as an efficient solar steam evaporator, after surface coating. [ABSTRACT FROM AUTHOR]

Hydrophilic-oleophobic porous materials, especially those fabricated from one-pot emulsion templating, are promising for removing water from oil-water mixtures, but the relatively dense covalent crosslinking makes the materials rigid and impossible for recycling, which hinders their real applications. Herein, we report the fabrication of hydrophilic-oleophobic aerogels with flexibility, stretchability and recyclability through high internal phase emulsion templating. The aerogels were formed through the interface-initiated condensation of perfluorooctyltriethoxysilane within the dispersed phase and the subsequent solidification of external aqueous phase through poly(vinyl alcohol) gelation. The resulting aerogels exhibited controllable external shapes, good flexibility, robust compression, high stretchability, and in-air hydrophilicity-oleophobicity. These features enabled the aerogels to remove water from not only free oil-water mixtures but also surfactant-stabilized water-in-oil emulsions through selective absorption, and the aerogels also showed good reusability. Since the aerogels were formed through physical gelation, they could be recycled and reshaped by dissolving in hot water, adding oil, and freeze drying. The as-recycled aerogels showed similar properties to that of the parent aerogels. [Display omitted] • Aerogel synthesis: Simultaneous interface-initiated reaction and polymer gelation. • Aerogels: Hydrophilicity-oleophobicity in air, flexibility, stretchability and recyclability. • Application: Removing water from oil-water mixtures (including emulsions). [ABSTRACT FROM AUTHOR]

[Display omitted] • Flexible and recyclable aerogels were fabricated from octadecane-in-water emulsions. • The aerogels showed controllable external shapes, robust compression and good encapsulation. • The aerogels had excellent heat storage properties, including high heat capacity and reusability. • The aerogels exhibited recyclability, with heat storage properties well preserved. Although emulsion-based, phase change material-encapsulated monolithic composites are promising for latent heat storage, their rigidity and non-recyclability imposed by the relatively dense covalent crosslinking hinder the composites from real applications. Herein, we report the fabrication of aerogel composites with flexibility and recyclability from cellulose nanocrystal-stabilized, octadecane-encapsulated Pickering emulsions solidified using physical gelation. The resulting monolithic composites exhibited controllable external shapes, and the introduction of poly(vinyl alcohol) significantly reduced the leakage of the encapsulated octadecane. The aerogel composites showed flexibility at temperature over 30 °C, and robust compressive behavior, without fracture at 70% compressive strain. The composites possessed similar heat storage (melting) temperature and heat release (crystallization) temperature to that of bulk octadecane, high heat capacity (up to 253 J.g−1) and high reusability, without obvious deterioration in heat capacity after 100 heating–cooling cycles. Moreover, the aerogel composites exhibited recyclability, simply by dissolving the composites in hot water to form emulsions and then by freeze drying to form aerogel composites. The flexibility and recyclability, together with robust compression, controllable external shapes, high heat capacity and good reusability, make the aerogel composites to be excellent candidates for latent heat storage. [ABSTRACT FROM AUTHOR]

Unlike oil‐absorbing hydrophobic and oleophilic materials, porous materials that simultaneously display hydrophilicity and oleophobicity in air are rare, but they are unique in selectively removing water from bulk oil. Preparation of such porous materials is limited to the surface coating of raw porous materials, which faces problems such as pore clogging and uneven coating on inner surfaces. Herein, a one‐pot approach to fabricating hydrophilic and oleophobic foams from oil‐in‐water high internal phase emulsions through a facile interface‐initiated polymerization strategy is reported. The foams have interconnected macroporous structure. They can absorb water drops quickly while repelling oils in air. Such foams may find applications not only in oil–water separation (e.g., fuel purification), but also for efficient removal of contaminants (e.g., dyes) from oil‐containing wastewater, where the oleophobicity helps foams to eliminate the oil fouling issue. [ABSTRACT FROM AUTHOR]