Greener processes in the preparation of thin film nanocomposite membranes with diverse metal-organic frameworks for organic solvent nanofiltration

Abstract

The toxic solvent dimethylformamide has been replaced by the greener dimethylsulfoxide in the casting and activation processes for the preparation of thin film composite (TFC) membranes. This methodology has been validated with the use of MOFs ZIF-8, ZIF-93 and UiO-66 as fillers for thin-film nanocomposite (TFN) membranes. These membranes were successfully applied in the organic solvent nanofiltration of sunset yellow (SY) in methanol obtaining the highest permeance when UiO-66 and ZIF-93 were used with a value of 11 L m−2 h-1 bar-1. The permeance improvements are related to the MOF porosity, polyamide-MOF layer thickness and the hydrophilic/hydrophobic character of the membrane.