Honeycomb-like cobalt hydroxide nanosheets induced basalt fiber fabrics with robust and durable superhydrophobicity for anti-icing and oil-water separation

The fiber-based membranes with superhydrophobic/superoleophilic features are highly desirable for oil-water separation applications. Herein, a superhydrophobic/superoleophilic basalt fiber fabric is constructed by using a general strategy of surface KMnO4 pre-oxidation, honeycomb-like cobalt hydroxide nanosheets in-situ deposition, and hydrophobization. The influence of morphology change on wettability and roughness of the fabric surface were investigated. Benefiting from the dual-scale micro-/nanostructures, the obtained composite fabric has outstanding superhydrophobicity (water contact angle > 161°) and sustains non-wettability against multifarious food liquids. Meanwhile, the fabric displays substantial superhydrophobic durability during sandpaper abrasion, tape-peeling, and bending treatment. Moreover, the fabric also demonstrates excellent anti-wetting, self-cleaning and anti-icing performance. With these properties, the fabric has outstanding separation efficiencies (> 99.31%) and recyclability for various oil-water mixtures and emulsions under gravity. Therefore, this work provides an idea for development of superhydrophobic fabrics with potential application in the rapid treatment of oily wastewater.