Poly(dimethylsiloxane) Oil Absorbent with a Three-Dimensionally Interconnected Porous Structure and Swellable Skeleton

Cleanup of oil spills is a worldwide challenge to prevent serious environmental pollution. A new kind of poly­(dimethylsiloxane) (PDMS) oil absorbent with high absorption capacity and excellent reusability was prepared and used for oil/water separation. The preparation process of PDMS oil absorbents involves direct curing of a PDMS prepolymer in a <i>p</i>-xylene solution in the presence of commercial sugar particles, which is simple and economic. PDMS oil absorbents have interconnected pores and a swellable skeleton, combining the advantages of porous materials and gels. Absorption capacities of PDMS oil absorbents are 4–34 g/g for various oils and organic solvents, which are 3 times that reported previously. Owing to their hydrophobicity and oleophilicity, the as-obtained PDMS oil absorbents can selectively collect oils or organic solvents from water. The absorption process can be finished within tens of seconds. Furthermore, the absorbed oils or organic solvents can be recovered by compressing the oil absorbents, and after 20 absorbing/recovering cycles, PDMS oil absorbents show little loss of their absorption capacities and own weights

Poly(dimethylsiloxane) Oil Absorbent with a Three-Dimensionally Interconnected Porous Structure and Swellable Skeleton

Cleanup of oil spills is a worldwide challenge to prevent serious environmental pollution. A new kind of poly­(dimethylsiloxane) (PDMS) oil absorbent with high absorption capacity and excellent reusability was prepared and used for oil/water separation. The preparation process of PDMS oil absorbents involves direct curing of a PDMS prepolymer in a <i>p</i>-xylene solution in the presence of commercial sugar particles, which is simple and economic. PDMS oil absorbents have interconnected pores and a swellable skeleton, combining the advantages of porous materials and gels. Absorption capacities of PDMS oil absorbents are 4–34 g/g for various oils and organic solvents, which are 3 times that reported previously. Owing to their hydrophobicity and oleophilicity, the as-obtained PDMS oil absorbents can selectively collect oils or organic solvents from water. The absorption process can be finished within tens of seconds. Furthermore, the absorbed oils or organic solvents can be recovered by compressing the oil absorbents, and after 20 absorbing/recovering cycles, PDMS oil absorbents show little loss of their absorption capacities and own weights

Poly(dimethylsiloxane) Oil Absorbent with a Three-Dimensionally Interconnected Porous Structure and Swellable Skeleton

Cleanup of oil spills is a worldwide challenge to prevent serious environmental pollution. A new kind of poly­(dimethylsiloxane) (PDMS) oil absorbent with high absorption capacity and excellent reusability was prepared and used for oil/water separation. The preparation process of PDMS oil absorbents involves direct curing of a PDMS prepolymer in a <i>p</i>-xylene solution in the presence of commercial sugar particles, which is simple and economic. PDMS oil absorbents have interconnected pores and a swellable skeleton, combining the advantages of porous materials and gels. Absorption capacities of PDMS oil absorbents are 4–34 g/g for various oils and organic solvents, which are 3 times that reported previously. Owing to their hydrophobicity and oleophilicity, the as-obtained PDMS oil absorbents can selectively collect oils or organic solvents from water. The absorption process can be finished within tens of seconds. Furthermore, the absorbed oils or organic solvents can be recovered by compressing the oil absorbents, and after 20 absorbing/recovering cycles, PDMS oil absorbents show little loss of their absorption capacities and own weights

Template-Free Synthesis of Amorphous Double-Shelled Zinc–Cobalt Citrate Hollow Microspheres and Their Transformation to Crystalline ZnCo₂O₄ Microspheres

A novel and facile approach was developed for the fabrication of amorphous double-shelled zinc–cobalt citrate hollow microspheres and crystalline double-shelled ZnCo₂O₄ hollow microspheres. In this approach, amorphous double-shelled zinc–cobalt citrate hollow microspheres were prepared through a simple route and with an aging process at 70 °C. The combining inward and outward Ostwald ripening processes are adopted to account for the formation of these double-shelled architectures. The double-shelled ZnCo₂O₄ hollow microspheres can be prepared via the perfect morphology inheritance of the double-shelled zinc–cobalt citrate hollow microspheres, by calcination at 500 °C for 2 h. The resultant double-shelled ZnCo₂O₄ hollow microspheres manifest a large reversible capacity, superior cycling stability, and good rate capability

Shape-Selective Formation of Monodisperse Copper Nanospheres and Nanocubes via Disproportionation Reaction Route and Their Optical Properties

Synthesis of stable and monodisperse Cu nanocrystals of controlled morphology has been a long-standing challenge. In this Article, we report a facile disproportionation reaction approach for the synthesis of such nanocrystals in organic solvents. Either spherical or cubic shapes can be produced, depending on conditions. The typical Cu nanospheres are single crystals with a size of 23.4 ± 1.5 nm, and can self-assemble into three-dimensional (3D) nanocrystal superlattices with a large scale. By manipulating the chemical additives, monodisperse Cu nanocubes with tailorable sizes have also been obtained. The probable formation mechanism of these Cu nanocrystals is discussed. The narrow size distribution results in strong surface plasmon resonance (SPR) peaks even though the resonance is located in the interband transition region. Double SPR peaks are observed in the extinction spectra for the Cu nanocubes with relative large sizes. Theoretical simulation of the extinction spectra indicates that the SPR band located at longer wavelengths is caused by assembly of Cu nanocubes into more complex structures. The synthesis procedure that we report here is expected to foster systematic investigations on the physical properties and self-assembly of Cu nanocrystals with shape and size singularity for their potential applications in photonic and nanoelectronic devices

Bioinspired Enzymatic Mineralization Incorporates CaCO₃ Mesocrystals in Wood for Surface Reinforcement and Flame-Retardancy

The development of sustainable strategies for the integration of wood with excellent mechanical and fire-retardant properties is increasingly appealing to bridge this renewable engineering material with multiple emerging applications. Inspired by biomineralization on soft tissues for a protective function, we developed enzymatic mineralization for the deposition of CaCO3 minerals in wood compartments. The immobilized urease in vessels and fibers increased the local concentration of bicarbonate anions, which, together with the directional diffusion of calcium cations, caused the deposition of calcitic CaCO3 mineral preferentially in cellular compartments of cells near the wood surface. The employment of the polymeric additives ensured that multistage mineralization started on the lumen-facing cell wall surfaces, and the local space in the lumina was filled with mesocrystalline CaCO3 deposits after multiple rounds of enzymatic mineralization. The incorporation of rod-shaped CaCO3 mesocrystals resulted in mineralized wood with improved surface hardness, and flame-retardancy, while at the same time, the moderate incorporation level preserved the intrinsic lightweight merit of wood. This bioinspired enzymatic mineralization approach can regulate the positioning and structure of functional minerals for the fabrication of high-performance mineralized wood in a sustainable manner

Facile Preparation of Well-Dispersed CeO₂–ZnO Composite Hollow Microspheres with Enhanced Catalytic Activity for CO Oxidation

In this article, well-dispersed CeO₂–ZnO composite hollow microspheres have been fabricated through a simple chemical reaction followed by annealing treatment. Amorphous zinc–cerium citrate hollow microspheres were first synthesized by dispersing zinc citrate hollow microspheres into cerium nitrate solution and then aging at room temperature for 1 h. By calcining the as-produced zinc–cerium citrate hollow microspheres at 500 °C for 2 h, CeO₂–ZnO composite hollow microspheres with homogeneous composition distribution could be harvested for the first time. The resulting CeO₂–ZnO composite hollow microspheres exhibit enhanced activity for CO oxidation compared with CeO₂ and ZnO, which is due to well-dispersed small CeO₂ particles on the surface of ZnO hollow microspheres and strong interaction between CeO₂ and ZnO. Moreover, when Au nanoparticles are deposited on the surface of the CeO₂–ZnO composite hollow microspheres, the full CO conversion temperature of the as-produced 1.0 wt % Au–CeO₂–ZnO composites reduces from 300 to 60 °C in comparison with CeO₂–ZnO composites. The significantly improved catalytic activity may be ascribed to the strong synergistic interplay between Au nanoparticles and CeO₂–ZnO composites

Ag@Co_<i>x</i>P Core–Shell Heterogeneous Nanoparticles as Efficient Oxygen Evolution Reaction Catalysts

We present a facile synthetic method that yields Ag@Co_<i>x</i>P core–shell-type heterogeneous nanostructures with excellent oxygen evolution reaction (OER) activity. This nanocatalyst can deliver a current density of 10 mA/cm² at a small overpotential of 310 mV and exhibits high catalytic stability. Additionally, the catalytic activity of Ag@Co_<i>x</i>P is 8 times higher than that of the Co₂P nanoparticles, owing primarily to the strong electronic interaction between the Ag core and the Co_<i>x</i>P shell