Flexible 3D porous superhydrophobic composites for oil-water separation and organic solvent detection

Abstract

Flexible porous composites, as sorbent materials with shape recoverability and excellent adsorption capacity, have always attracted many attentions in these years. In order to endow the sponge with selective adsorption, the sponge needs to be prepared as a superhydrophobic material. In this paper, the nano-graphite flakes were adhered to the melamine sponge by polydimethylsiloxane, and then the sponge was silanized with hexadecyltrimethoxysilane to prepare a superhydrophobic conductive sponge. The prepared sponge has excellent adsorption capacity for oil and organic solvent. It can not only absorb 24–40 g of organic solvent per gram of sponge, but also absorb oil in the oil-in-water emulsion. After the emulsion separation, the COD value of the emulsion can be reduced to 260 mg/L. Even after hundreds of adsorption-extrusion cycles, it can still maintain more than 92% of the adsorption capacity for organic solvents. In addition, its electrical conductivity makes it having potential application for pressure sensors. After adsorbing different organic solvents, the composite exhibits particular current changes and can be used as a sensor for organic solvents to detect the presence of different types of organic solvents.