Superhydrophobic Fabric Resistant to an Aqueous Surfactant Solution as Well as Pure Water for the Selective Removal of Spill Oil

Poly(dimethylsiloxane) (PDMS)-coated SiO2 nanoparticles were deposited on the surface of nonwoven cotton fabric, and the behavior of the fabric as a function of the amount of deposited PDMS-coated SiO2 was systematically studied. When PDMS-coated SiO2 nanoparticles were deposited on the cotton while leaving the geometry of each strand and interstitial gaps between neighboring strands of fabric identifiable, the surface showed high repellency toward pure water but not surfactant aqueous solutions. Only when the amount of PDMS-coated SiO2 nanoparticles was further increased such that the structure of each strand and interstitial gaps were buried by an additional layer of PDMS-coated SiO2 nanoparticles was repellency toward the surfactant (contact angle: ∼160°) solution also achieved. It was also demonstrated that our hydrophobized cotton fabric can efficiently isolate oil from an oil–water emulsion with surfactants; the separation efficiency of our sample for various oil–water emulsions was quantitatively analyzed. We suggest that our method for fabricating superhydrophobic fabric could be widely applicable to spill-oil removal.