Highly efficient deep eutectic solvents coated MIL-53(Fe) embedded polyvinylidenefluoride MMMs for phenol separation using pervaporation

Abstract

Novel hydrophilic pervaporative mixed matrix membranes (MMMs), comprising deep eutectic solvent-coated MIL-53(Fe) embedded polyvinylidenefluoride (PVDF) matrix, are prepared to remove phenol from the water. Double cone hexagonal prism type MIL-53(Fe) nanofillers are first synthesized by hydrothermal method and then encapsulated with deep eutectic solvent (DES) solution by a deep coating process. The DES-coated MIL-53(Fe) nanofillers are added to the PVDF matrix to prepare the MMMs using the non-solvent-induced phase-separation (NIPS) process. The prepared DES@MIL-53(Fe) and MMMs are characterized by various analytic techniques to verify the successful addition of the nanofillers into the PVDF matrix. The highest pure water flux (PWF) values of nearly 126 L m−2h−1 are observed with a DES@MIL-53(Fe) loading of 7.5 wt% in the polymer dope solution for MMMs, which is three times higher than pure PVDF membrane values (41.5 L m−2h−1). The DES@MIL-53(Fe)/PVDF MMMs showed nearly 215% enhancement in pure water flux (131.66 L m−2h−1) and ∼ 107% enhancement in the phenol removal efficiency (93.22%) for the 50-ppm phenol solution as compared to pure PVDF membranes. Further, the experiments are carried out within a wide range of feed concentrations (feed concentration: 15–90 ppm) and feed pH (pH: 1–13) to study the separation performance of the MMMs.