Incorporação de óxido de grafeno em membranas compostas de poliamida visando a melhoria de desempenho em sistemas de osmose inversa

Abstract

Potable water has become a valuable, and sometimes, scarce resource due to population growth and the industrial activities. Therefore, technologies that can process and generate this product are necessaries to avoid a global scenario of water scarcity in the next years. Reverse osmosis desalination using membranes is one of the most used strategies today to produce potable water. There are many studies to improve membrane’s performance, one of them is incorporating graphene oxide into the polymeric matrices due to its hydrophilicity. In order to improve their performance, it was studied in this work the incorporation of graphene oxide on the support of polysulfone and polyamide film. The porous supports were prepared using the phase inversion method and the nanoparticles were added in the solution of the polysulfone on different concentrations. The polysulfone membranes produced were characterized on a gas permeation system. The average permeance using nitrogen was 456 GPU for the pure membranes and 1370 GPU for the membranes with 0,2% m/m graphene oxide. The dense layer of polyamide was synthesized through the interfacial polymerization method. Results of scanning electron microscopy confirmed the formation of a thin film layer. Gas permeation tests showed that the permeance reduced to 170 GPU using nitrogen. Hydraulic permeability was obtained by using a reverse osmosis system for permeation. It was observed that both permeability and salt rejection improved. Hydraulic permeability increased from 2.7 to 3.4 L/h.m².bar while salt rejection increased from 13,6 to 31,2%. These results showed that the nanoparticle improves membrane performance for desalination systems.