title: Reversible conversion of water-droplet mobility from rollable to pinned on a superhydrophobic functionalized carbon nanotube film.
abstract: Poly(acrylic acid)-block-polystyrene (PAA-b-PS) functionalized multiwall carbon nanotubes (MWNTs) were prepared by nitroxide-mediated "living" free-radical polymerization. The product functionalized MWNTs (MWNT-PAA-b-PS) contained 20% by weight PAA-b-PS based on the infrared spectroscopy analysis and thermal gravimetric analysis. Such MWNT-PAA-b-PS nanoparticles can be used in spray coating method to fabricate superhydrophobic MWNT films, and water-droplet mobility on the superhydrophobic film can be reversibly converted from rollable to pinned through adjusting the appearance of PAA chains on the topmost surface of the film. Switching mechanism has been discussed in detail. We also directly observed the air-solid-liquid interface from the above of a water droplet by a microscope to confirm the superhydrophobic states, and proved that the transition between the wettability states appeared on the same surface with reversible conversion of water-droplet mobility.
authors.affiliation: State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Zhaozhu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xuehu
authors.initials: X
authors.lastname: Men
authors.forename: Xianghui
authors.initials: X
authors.lastname: Xu
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008567:Membranes, Artificial; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D058105:Polymerization; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D000179:Acrylates; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D011137:Polystyrenes; C509855:poly(styrene-b-acrylic acid); D014867:Water