Fabrication of PEBA/Cu2O mixed-matrix membranes and their application in pyridine recovery from aqueous solution

Abstract

The lone pair of electrons of the pyridine nitrogen atom can form a complex with some metal ions such as Cu⁺, Ag⁺, etc. Therefore, in this paper, Cu₂O nanocrystal particles were synthesized and incorporated into polyether-block-amides (PEBA) to prepare novel PEBA/Cu₂O mixed-matrix membranes (MMMs). The prepared Cu₂O/PEBA MMMs were characterized by Fourier-transform infrared spectrum (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and contact angle goniometer. The effects of Cu₂O incorporation on swelling and the pervaporation performance of Cu₂O/PEBA MMMs were evaluated with pyridine/water binary mixtures. The results indicated that the separation factor increased first, and then decreased, with increasing Cu₂O content, which subsequently led to a decrease in permeation flux. The optimal performance was achieved when the weight fraction of Cu₂O in the PEBA/Cu₂O MMMs was 6.0 wt% with a flux of 89.3 g m⁻² h⁻¹ (decreased by 13.1% compared with the pristine PEBA membrane) and separation factor of 10.22 (increased by 22.8% compared with the pristine PEBA membrane) for a 1.0 wt% pyridine aqueous solution at 30 °C. The influence of process parameters such as feed temperature and feed pyridine concentration on pervaporation performance were also investigated. This work demonstrated that PEBA/Cu₂O MMMs could be considered as potential candidates for practical pyridine production recovery.