Preparation and characterization of mixed matrix polymeric membranes from SAN and organophilic clay

ABSTRACT

Water contamination due to the disposal of emerging pollutants such as antibiotics, pesticides, food additives and other organic pollutants has adverse effects on human health and is a global environmental problem that needs immediate action. Membrane technology is an effective and attractive alternative to this treatment, offering high separation efficiency, low energy consumption, and greater operational flexibility. In addition, great attention has been paid to nanotechnology, which allows the production of materials with properties such as hydrophilicity, permeability and resistance. The present work aims at the preparation and characterization of mixed matrix polymeric membranes. These were prepared by the phase inversion technique, using the copolymer of styrene and acrylonitrile (SAN) as polymeric precursor, with the addition of organophilic clay (0, 1.5 and 3.0% (m/m)) and as a solvent N-methyl-2-pyrrolidone (NMP). From the analysis of the SEM results, it was found that the membranes presented an asymmetrical structure, composed of a thin selective layer on top, finger-like macroempty that extend through the membrane, with few or no defects in the membrane surface. When observing the effect of the addition of clay, it was noticed that it caused an apparent increase in the selective layer and the decrease in the porous layer, it was observed that the addition of clay to a concentration of 3% caused the formation of apparent defects, making it brittle. Based on the results of the BJH analysis, it was concluded that the membranes showed a wide distribution of pores in the range of meso, macro or micropores.

Keywords
Membranes; Nanocomposite; Clay; SAN.