AUTHOR=Alwael H. , Alsulami A. N. , Abduljabbar T. N. , Oubaha M. , El-Shahawi M. S. 

TITLE=Innovative Sol-gel functionalized polyurethane foam for sustainable water purification and analytical advances

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2024.1324426

DOI=10.3389/fchem.2024.1324426

ISSN=2296-2646

ABSTRACT=Nanomaterial combined polymeric membranes such as polyurethane foams (PUFs) have gathered extra attraction to the adoption of water purification due to their ease of management and surface modification, cost-effective, and mechanical, chemical and thermal properties.Thus, the current study reports the use of novel Sol-gel impregnated polyurethane foams (Solgel/PUFs) as new dispersive solid phase microextractors (d-µ SPME) for efficient separation and subsequent spectrophotometric detection of Eosin Y (EY) textile dye in aqueous solution of pH 3-3.8. The Sol gel, PUFs and Sol gel impregnated PUFs were characterized via scanning electron microscopy (SEM), goniometry measurements, dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), UV-Visible and FTIR spectra. Batch experiments results displayed remarkable removal percentage (96±5.4 %) of the EY from the aqueous solution with total sorption time not exceeding 60 min. These data indicative of the rate-limited sorption via diffusion and/or surface complex ion associate formations after rapid initial sorption steps. A pseudo-second order kinetic model thoroughly explained the sorption kinetics, providing sorption capacity (qe) of 37.64 mg g -1 , half-life time (t1/2) of 0.8 ± 0.01 min and intrinsic penetration controls dye retention. The thermodynamic results revealed negative value for ΔG • (-78.07 kJ mol -1 at 293 K) clearly signifying that, the dye uptake was spontaneous as well as negative value for ΔH ⁰ (-69.58 kJ mol -1 ) and positive value of ΔS ⁰ (147.65 J mol -1 K -1 ) making clear the exothermic nature of EY adsorption onto the sorbent with an growth in randomness at a molecular level, respectively. A ternary retention mechanism involving "weak base anion exchanger" of {(-CH2-OH + -CH2-) (Dye anion) -}Sol-gel/PUF and/or {(-NH2 + -COO-) (Dye anion) -} Sol-gel/PUF via solvent extraction; "surface adsorption" of the dye anion on/in the Sol-gel/PUFs membranes in addition to H-bonding including surface complexation and electrostatic π-π interaction resulted between the dye and the silicon/zirconium oxide (Si-O-Zr) and siloxane (Si-O-Si) groups on the sorbent is proposed.