Hybrid Microporous Membranes Applied in Wastewater Treatment

Abstract

In this work, membranes of pure polyamide 6 (PA6) and hybrids with 1, 3, and 5% in weight of organophilic montmorillonite (OMMT) clay in the form of thin porous films are obtained by the phase inversion technique. The membranes are characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), contact angle (CA), and flow measurements (FM). Through X‐ray diffraction, it is revealed that the hybrid membranes with OMMT have an exfoliated and/or partially exfoliated structure. From FTIR and DSC analyses of hybrid membranes with OMMT, it is found that the spectra and the crystalline melting temperature remained practically unchanged compared to PA6 membrane. From the SEM, it is verified that the addition of the clay caused an increase in the quantity and uniformity of pores distribution in the surface and cross section of these membranes. By MIP, it is observed that the presence of clay in the membrane caused an increase in the average pore diameters. By the contact angle, it is verified that the membrane with clay had a higher value of contact angle for the distilled water when compared to the angle obtained with the synthetic oil. The water flux of the membrane with clay is higher than that obtained by the membrane of pure PA6, due its surface structure with larger pore diameters, favoring its permeability. The obtained hybrid membrane presented adequate porosity morphology for wastewater treatment.