The fabrication of robust superhydrophobic 3D porous materials is of great importance for both academic research and industrial applications. The main challenge is the poor adhesion between porous substrates and superhydrophobic coatings. In this study, a robust superhydrophobic polysiloxane layer was coated onto the surface of 3D porous polyurethane sponges through a one-step solution immersion method.The durability of the resulting sponges was investigated by repeated mechanical compressions, ultrasonication in polar solvents, and strong acid/alkali attacks. Results revealed that the superhydrophobic sponges showed excellent elasticity, high mechanical durability and good chemical stability. By combining the special wettability and high porosity, the sponges exhibited high oilabsorption capacity and high selectivity when they were employed as absorptive materials for cleaning oils on the water surface. More importantly, the superhydrophobic sponges could be reused for oil-water separation for more than 300 cycles without losing their superhydrophobicity, exhibiting the highest reusability and durability among the reported counterparts. Therefore, the present study offers a simple and low-cost strategy for large-scale fabrication of robust superhydrophobic 3D porous materials that might be applied to the cleanup of oil spills on the water surface.

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Immobilization of various nanoparticles onto complex 2D or 3D macroscopic surface is an important issue for nanotechnology, but the challenge remains to explore a facile, general and environmentally friendly method for achieving this goal. Taking inspiration from the adhesion of marine mussels, we reported here that oxide nanoparticles of different compositions and sizes were directly and robustly anchored on the surface of monolithic foams ranging from polymer to metals in an aqueous solution of dopamine. The effective immobilization of the nanoparticles was strongly dependent on the oxidation of dopamine, which could be tuned by either pH or by adding n-dodecanethiol. Interestingly, the thiol addition not only allowed the immobilization to take place in a wide pH range, but also led to superhydrophobicity of the resulting foams. Application of the superhydrophobic foams was illustrated by fast and selective collecting oils from water surface. Because catecholic derivatives exhibit high affinity to a variety of substances, the present strategy might be extendable to fabricate hybrid nanomaterials desirable for self-cleaning, environmental protection, sensors and catalysts, and so forth.

The removal of oil spills or organic contaminants from water surface is of great technological importance for environmental protection. A major challenge is the fast distribution and collection of absorbent materials with high separation selectivity, good thermal stability, and excellent recyclability. Here we reported fast and selective removal of oils from water surface through core-shell Fe(2)O(3)@C nanoparticles under magnetic field. These nanoparticles combined with unsinkable, highly hydrophobic and superoleophilic properties, could selectively absorb lubricating oil up to 3.8 times of the particles' weight while completely repelling water. The oil-absorbed nanoparticles were quickly collected in seconds by applying an external magnetic field. More importantly, the oil could be readily removed from the surfaces of nanoparticles by a simple ultrasonic treatment whereas the particles still kept highly hydrophobic and superolephilic characteristics. Experiment results showed that the highly hydrophobic Fe(2)O(3)@C nanoparticles could be reused in water-oil separation for many cycles. Our results suggest a facile and efficient method that might find practical applications in the cleanup of oil spills and the removal of organic pollutants on water surface.

The effect of edge-functionalization on the competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons (NPCs) has been investigated for the first time by combining density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulation. Our results show that edge-functionalization has a more positive effect on the single-component adsorption of CO2 than CH4, therefore significantly enhancing the selectivity of CO2 over CH4, in the order of NH2-NPC > COOH-NPC > OH-NPC > H-NPC > NPC at low pressure. The enhanced adsorption originates essentially from the effects of (1) the conducive environment with a large pore size and an effective accessible surface area, (2) the high electronegativity/electropositivity, (3) the strong adsorption energy, and (4) the large electrostatic contribution, due to the inductive effect/direct interaction of the embedded edge-functionalized groups. The larger difference from these effects results in the higher competitive adsorption advantage of CO2 in the binary CO2-CH4 mixture. Temperature has a negative effect on the gas adsorption, but no obvious influence on the electrostatic contribution on selectivity. With the increase of pressure, the selectivity of CO2 over CH4 first decreases sharply and subsequently flattens out to a constant value. This work highlights the potential of edge-functionalized NPCs in competitive adsorption, capture, and separation for the binary CO2-CH4 mixture, and provides an effective and superior alternative strategy in the design and screening of adsorbent materials for carbon capture and storage.