Rapid oil-water separation using modified nonwoven viscose fabrics

Abstract

Two saturated fatty acids, namely palmitic acid (PA) and lauric acid (LA) were incorporated with glycidoxypropyl methoxy silane (GPTMS) into the nonwoven viscose fabric (NWVF) via chemical refluxation methodology. FE-SEM, EDS, and XPS analysis portray the existence of siloxane polymeric functionality on the fabric's surface. The 29Si solid-state NMR results reveal that the comprehensive peak position at −60.9 ppm attributed to the silicone atom of T3 structural unit [C–Si(OSi)3] and −54.9 ppm ascribed to the T2 unit [C–Si(OR)(OSi)2] which enrich the properties of fabrics towards the depletion of oil/organic solvents contamination from water. The modified viscose fabric surface showed outstanding superhydrophobic behavior with the respective WCA of 173 ± 2° for PA-GPTMS coated NWVF and 167 ± 2° for LA-GPTMS coated NWVF. Further, the constructed fabrics displayed high superoleofilicity to the oil and solvents with a contact angle of 0° distinctly. Thus, the chemically modified fabrics were inherently applied for the separation of the oil-water mixture and organic solvents. Surprisingly, it showed excellent separation efficiency for oil about 99 %, and organic solvents around 97 % respectively. The oil absorption capacity studies also demonstrated a high absorption volume of 14 g/g (18 ml/g) for PA-GPTMS-coated NWVF, and 13 g/g (17 ml/g) for LA-GPTMS-coated NWVF materials. The surface-modified materials were investigated for sustainability and lifespan. Remarkably, the PA-GPTMS-coated NWVF material showed admirable results of superhydrophobic/superoleophilic behavior retained (WCA >150°) in a harsh environment (70 h at 120 °C) and oil-water separation over 30 recycles. The above results suggested that the chemically modified nonwoven viscus fabrics would be a suitable potential candidate for the industrial-scale separation of immiscible oils/organic solvent contamination in water.