Effect of loading various nanoparticles on superhydrophobic/superoleophilic stearic acid-modified polyurethane foams for oil-water separation

Abstract

This report has been generated to synthesize certain superhydrophobic/superoleophilic materials by modifying the polyurethane nanocomposite with three different nanoparticles (NPs). The general purposes are to study the effect of the nanoparticles and remove oil contaminants from water, which is highly required following the impact of technology development in various fields. The materials were produced by dip-coating in-situ method upon a polyurethane foam (PUF) and directly continued with the insertion of nanoparticles and a stearic acid (SA) branch through ultrasonication for further transformation. Additionally, characterization by SEM/EDX, TGA, and FTIR presented that the nanoparticle composites were uniformly distributed through the PUF, caused as a result of the intense chelating bond bonded between NPs active surface and the carboxylates-hydroxide. Notably, the water contact angle (WCA) measurement showed that the static contact angle escalated up to 162°. Interestingly, after 20 cycles of the absorption-desorption test, the WCA remained above 135° which strongly affirmed the excellent superhydrophobic properties of the modified PUF nanocomposites. Furthermore, their performance in oil-water separation was tested with different organic and commercial oil to compare the capacity rate, reusability, permeate flux, and separation efficiency of each material. The results exhibited that the surface alteration of the PUF enhanced the oil capacity up to 35–37 g/g, oil permeate flux as much as 8000 L m−2 h−1, and separation efficiency up to 99.5% respectively. Moreover, the colored oil in the oil removal test was rapidly absorbed by the materials within 2sconfirming the high applicability in a wider area of oil-water separation. Notably, these remarkable results demonstrated that the fabricated PUF absorbents were capable to be used in industrial applications owing to their high performance, and mechanical, and chemical stability. Finally, the effect of loading different NPs (Al, Fe, and Zn) was studied that the Fe NPs are the most excellent nanoparticles for all the performance tests.