After hydrothermally treated in H2O (for Mg alloy and Al alloy) or H2O2 (for Ti alloy), microstructured oxide or hydroxide layers were formed on light alloy substrates, which further served as the active layers to boost the self-assembling of 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) and finally endowed the substrates with unique wettability, that is, superhydrophobicity. For convenience, the so-fabricated superhyrdophobic surfaces (SHS) were abridged as HT-SHS. For comparison, SHS coded as CE-SHS were also prepared based on chemical etching in acid and succedent surface passivation with PFOTES. To reveal the corrosion protection of these SHS, potentiodynamic polarization measurements in NaCl solution (3.5 wt %) were performed. Moreover, to reflect the long-term stability of these SHS, SHS samples were immersed into NaCl solution and the surface wettability was monitored. Experimental results indicated that HT-SHS was much more stable and effective in corrosion protection as compared with CE-SHS. The enhancement was most likely due to the hydrothermally generated oxide layer by the following tow aspects: on one hand, oxide layer itself can lower the corrosion due to its barrier effect; on the other hand, stronger interfacial bonding is expected between oxide layer and PFOTES molecules.

The design, synthesis and application of iron-based materials (oxides Fe2O3/Fe3O4, hydroxide FeOOH, sulfides FeS2 and their nanocomposites) with 1D, 2D, and 3D nanostructure are fully summarized in this review.

We have prepared a porous, superoleophilic and superhydrophobic miniature oil containment boom (MOCB) for the in situ separation and collection of oils from the surface of water. The MOCB was fabricated by a one-step electrodepositing of Cu2O film on Cu mesh surface without using low surface energy materials. Oils on water surface could be fast contained in the MOCB while water was completely repelled out of the MOCB, thus achieving the separation of oil from water surface. In addition, the contained oil in the MOCB could be in situ collected easily by a dropper, thus achieving the collection of oil. Moreover, the MOCB could be reused for many times in the oil-water separating process with large separation abilities more than 90%. The MOCB also possessed excellent water pressure resistance for about 164 mm water column and good corrosion resistance in simulating seawater. Therefore, the findings in the present study might offer a simple, fast, and low-cost method for the in situ separation and collection of oil spills on seawater surface.

We report a convenient route to fabricate superoleophobic surfaces (abridged as SOS) on copper substrate by combining a two-step surface texturing process (first, the substrate is immersed in an aqueous solution of HNO3 and cetyltrimethyl ammonium bromide, and then in an aqueous solution of NaOH and (NH4)2S2O8) and succeeding surface fluorination with 1H,1H,2H,2H-perfluorodecanethiol (PFDT) or 1-decanethiol. The surface morphologies and compositions were characterized by field emission scanning electron microscopy and X-ray diffraction, respectively. The results showed that spherical micro-pits (SMP) with diameter of 50-100 μm were formed in the first step of surface texturing; in the second step, Cu(OH)2 or/and CuO with structures of nanorods/microflowers/microballs were formed thereon. The surface wettability was further assessed by optical contact angle meter by using water (surface tension of 72.1 mN m(-1) at 20°C), rapeseed oil (35.7 mN m(-1) at 20°C), and hexadecane (25.7 mN m(-1) at 20°C) as probe liquids. The results showed that, as the surface tension decreasing, stricter choosing of surface structures and surface chemistry are required to obtain SOS. Specifically, for hexadecane, which records the lowest surface tension, the ideal surface structures are a combination of densely distributed SMP and nanorods, and the surface chemistry should be tuned by grafted with low-surface-energy molecules of PFDT. Moreover, the stability of the so-fabricated sample was tested and the results showed that, under the testing conditions, superhydrophobicity and superoleophobicity may be deteriorated after wear/humidity resistance test. Such deterioration may be due to the loss of outermost PFDT layer or/and the destruction of the above-mentioned ideal surface structures. For UV and oxidation resistance, the sample remained stable for a period of 10 days.

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We develop a simple strategy for the collection of oil spill using a miniature device. The device was enfolded from a sheet of copper mesh with surface superhydrophobicity and superoleophilicity. The copper mesh was fabricated through a simple thermal oxidation and surface modification process. The miniature device adsorbed various oils from the surface of oil− water mixture in its pores while repelling water completely. After the pores were full of oil, only oil could infiltrate into the device through the pores automatically and was finally concentrated into the device, showing its oil− water separating ability. Importantly, the concentrated oil in the device could be taken away by a dropper or pumped out, thus achieving the collection of oil for reuse. Additionally, after the concentrated oil was taken away, the device could be used in the next oil−water separating cycle without apparent decrease of its separation ability. Therefore, the findings in this work may offer a new strategy for the collection and reuse of various kinds of oils and other organic compounds from water surfaces.

No abstract

We present a miniature collector for the adsorption and collection of oil spill. The collector composed of a superhydrophobic copper mesh miniature box embedded with a superoelophilic polyurethane sponge. The superhydrophobic Cu mesh was fabricated by a simple immersing method, and the PU sponge is a commercial available material with superoleophilicity in itself. The miniature collector can adsorb different oils on water surface in the pores of the superhydrophilic PU sponge while repelled water due to the superhydrophobicity of the mesh. In addition, the adsorbed oils could be easily separated from the sponge by squeezing and then be collected for reuse. After the separation of adsorbed oil, the sponge could be used repeatedly with high separation efficiency. Furthermore, the as-prepared Cu mesh possesses stability in various solvents and corrosion resistance in NaCl aqueous solution. The findings might provide a simple method for oils spill cleanup.