Magnetically Superamphiphobic Nanoparticles for Magnetic Response Surface Preparation.

Smart surfaces prepared using superhydrophobic coatings have been used to control the movement of tiny aqueous droplets for many years. However, the control of both aqueous droplets and oily droplets is still a challenge. Herein, a novel smart superamphiphobic composite film is developed with a superamphiphobic and magnetic surface as well as a soft elastic substrate for liquid droplets manipulation. The raspberry-like nanoparticles on the surface are synthesized by co-hydrolyzation of fluoroalkyl silane and tetraethoxysilane on iron oxide nanoparticles. The resulting composite nanoparticles (F/SiO2@Fe3O4 NPs) exhibit excellent superhydrophobicity (WCA of about 170°) and superoleophobicity (OCA of about 160°) as well as magnetism (saturated magnetization value of 12.0 emug-1). The morphologies of the F/SiO2@Fe3O4 NPs were investigated by transmission electron microscopy and scanning electron microscopy. Chemical composition and magnetization value of these magnetic nanoparticles as well as the magnetic field induced droplets manipulation behavior of the smart surface were also evaluated. The smart surface can realize the manipulation of both water droplets and oil droplets, which demonstrates potential applications in microfluidic technologies.