Fabrication of plasma-treated superhydrophobic polydimethylsiloxane (PDMS) – Coatėd melamine sponge for enhanced adhesion capability and sustainable oil/water separation

Abstract

A persistent global issue is the need for developing novel absorbent materials with high absorption efficacy and rapid absorption rates for effective oil–water separation. This work presents a novel, resilient, and recyclable material with exceptional sorption capabilities, achieved through a simple surface modification of melamine sponge (MS) using Argon plasma treatment followed by Polydimethylsiloxane (PDMS) polymer coating (Ar-PT/PDMS@MS). This study also delineates the choiceful impact of atmospheric and vacuum plasma over the surface modification of MS. The material's super hydrophobicity, demonstrated by a high-water contact angle of ∼165°, is enhanced using novel plasma treatment to homogenously coat PDMS polymer. This treatment also imparts sturdiness to withstand harsh environmental conditions. The modified 3D networked structure of melamine sponge with a porous core was able to selectively absorb the oil of various densities with the capacity range of 42–139.5 mg/g. The batch and continuous O/W separation studies revealed the efficiency of the modified MS to be able to selectively separate light nonaqueous phase liquids (LNAPL) and dense nonaqueous phase liquids (DNAPL) oil with more than 99% efficiency. The continuous studies showed that using diesel oil the separation efficiency was >99% for 35 L of oil for more than 5 h. It was also discovered that it outperformed and exceeded commercial absorbent materials in terms of absorption capacity. The recyclability studies highlighted the ability of the modified MS to be used for more than 10 cycles without compromising its separation efficiency. These findings may foreshadow Ar-PT/PDMS@MS's ability to be a promising antagonist for oil–water (O/W) separation in real-world oil-spill scenarios.