A Janus porous sphere with a coral-like microstructure is prepared by stepwise dealloying a metallic alloy sphere and sequential modification (for example, using silanes and polymers). Nanoscale coral-like microstructure of the internal skeleton gives remarkable capillary force, thus accelerating the mass transportation. Starting from the outer layer of the sphere, stepwise dealloying can achieve different layers inwardly, thus introducing different composition and performance. As an example, poly(ethylene glycol)–poly(N-isopropylacrylamide) (PEG–PNIPAM)- and poly(ethylene glycol)–poly(N,N-diethylamino-2-ethylmethacrylate) (PEG–PDEAEMA)-responsive Janus porous spheres can quickly capture oil by simply changing temperature or pH. Similarly, release is also triggered.Keywords: capillary force; coral microstructure; dealloying; Janus; porous; responsive;

A facile approach for the synthesis of responsive polymer composite nanotubular organogelators in large scale is reported. The exterior surface of the nanotubes is coarsening and hydrophobic after favorable growth of paramagnetic nanoparticles and oleic acid modification. All the tested organic solvents with varied polarities can be fast gelated by the addition of the composite nanotubular organogelators. The formed gel is easily removed from water with a magnet. A thermal responsive polymer PNIPAM is used to modify the surface of the composite nanotubes, it endows the release of captured oil from the gel by decreasing temperature. The composite nanotubular organogelators are promising in collecting chemical spills from water.

An effective approach is proposed to fabricate a robust superhydrophobic coating constructed from hairy composite spheres. The hairy spheres mimic structure of the papillae on the surface of lotus leaf. The synthesis is based on template method and the corresponding PANi hairy spheres are prepared by polymerization induced diffusion growth via nanosized channels of a polymer cage. The composite spheres become more robust by coating a layer of inorganic materials onto the PANi hairy spheres. By using a middle adhesive layer of epoxy resin, the hairy spheres can be tightly attached to the substrate. The superhydrophobic coating is achieved with a contact angle of 159.9 ± 1.9° and tilt angle below 2° by a post hydrophobic modification with octadecyltrichlorosilane. Such coating is robust enough to resist water flushing and organic solvents. This method can be scaled up for almost all kinds of substrates.