Facile fabrication of multi superlyophobic nano soil coated-mesh surface with excellent corrosion resistance for efficient immiscible liquids separation

Abstract

A novel strategy for spraying nanosized soil particles on steel mesh to prepare the superlyophobic soil mesh by a facile surface treatment technology, and successfully apply it to various immiscible liquids separation. • A multifunctional, sustainable material for immiscible liquid mixtures separation. • Under nonpolar (polar) liquid superlyophobicity of polar (nonpolar) liquid. • Used chemical properties-structure relationships to give material performance. • Low cost manufacturing, environment friendly, dimplicity of operator. • Good corrosion resistance in acidic, alkaline and high salt environment. Immiscible liquids separation has recently become a worldwide challenge due to the expanding industrial activity. It is still thorny to put forward a universal strategy for constructing multi-superlyophobic surfaces in immiscible liquids systems due to a thermodynamic contradiction. Herein, a low-cost, environmentally friendly pre-wetted nanosized soil coated-mesh (NSCM) was prepared, which shows the property of under-nonpolar-liquid superlyophobic to polar liquid, or under-polar-liquid superlyophobic to nonpolar liquid. The NSCM was fabricated in aqueous solutions by spraying melamine formaldehyde resin modified nanosized soil particles on a stainless-steel mesh for selective immiscible liquid separation. After the NSCM is prewetted with heavy liquid, heavy liquid can be removed from the light immiscible liquid mixtures by gravity. The as-prepared NSCM showed a high separation efficiency of above 99% for a series of immiscible liquids mixtures, even after 60 separation cycles. More importantly, the electrochemical tests indicated that the NSCM exhibited the outstanding durability after being immersed in alkali (pH = 10.0, NaOH), acidic (pH = 4.0, HCl) and high-concentrated salt solutions (3.5 wt% NaCl) for 30 days. The calculated R t values were approximately 1.04 × 10 7 , 2.65 × 10 6 and 7.59 × 10 5 Ω·cm 2 , respectively. And the corresponding corrosion rates were 0.013712, 0.96438, and 2.5818 μm/year, respectively. These excellent performances of the NSCM make it an ideal candidate material for separation, and even in a wider field of sea wastewater treatment.