Bioinspired Superhydrophobic Fe₃O₄@Polydopamine@Ag Hybrid Nanoparticles for Liquid Marble and Oil Spill

KGaA, Weinheim. Fe3O4nanoparticles (NPs) with Ag NPs evenly distributed on the surface are fabricated by using polydopamine (PDA) as the intermediate layer. Silanization and thiol chemistry are used to firmly combine the Fe3O4@ PDA core and outer surface Ag NPs. The spherical and hybrid nanoparticles are termed Fe3O4@PDA@Ag NPs, which possess a core-shell and hierarchical structure. After surface modification with 1H,1H,2H,2H-perfluorodecanethiol, the hybrid Fe3O4@PDA@Ag NPs become highly hydrophobic. Slight rolling of a water droplet on the as-prepared NPs causes the formation of a "liquid marble", which is capable of performing remote actuation on various solid surfaces, such as glass sheet, paper, plastic, textile, and ceramic, and at the liquid-air interface using a permanent magnet. Liquid marbles with self-assembled NPs on the liquid surface have potential to act as a miniaturized reactor for manipulation of inner liquid droplet with high positioning precision. In addition, the Fe3O4@PDA@Ag NPs are multifunctional and can be applied for oil/water separation and antibacterial purpose. Fe3O4@PDA@Ag nanoparticles with core-shell and hierarchical structure are prepared via combination of mussel-inspired chemistry and thiol chemistry. The multifunctional nanoparticles with several hundred nanometers can self-assemble on liquid droplets to form liquid marbles with millimeter scale for potential applications of tiny liquid transfer, microreactor, and gas sensing. They can also be applied for oil/water separation and antibacterial purpose.