A new perspective of functionalized MWCNT incorporated thin film nanocomposite hollow fiber membranes for the separation of various gases

Abstract

As the increasing demand for gas separation technologies in the industry, the polymeric membrane separation technology has received wide attention based on the advantages of high gas permeance, and low cost. Thin film nanocomposite (TFN) membranes used for the gas separation in industrial level is one of the best choices, because of applied nanoparticles synergistic properties influence to enhance gas permeance and selectivity. In this study thin selective nanocomposite layer has been developed using interfacial polymerization between 3,5-diaminobenzoic acid (DABA) with carboxylated multi-walled carbon nanotubes (C-MWCNTs) and trimesoyl chloride (TMC) on the surface of polysulfone hollow fiber substrate for the separation of various gases like water vapor, H2, CO2, CH4 and N2. Different concentrations of C-MWCNTs are used for the preparation of various TFN membranes. All prepared TFN membranes were well characterized using different physiochemical characterization techniques like ATR-FTIR, AFM, SEM, XPS, contact angle etc. It is found that the prepared membranes are not only used for the separation of water vapor but also utilize for the separation of different gases like H2, CO2, CH4, and N2. The TFN hollow fiber membranes prepared with 0.04 % C-MWCNTs, (C-MWCNT@DT-M4) show good performance in the form of permeance and selectivity among all the prepared membranes, as a water vapor permeance 2570 GPU, H2 permeance 92.5 GPU, along with the water vapor/N2 641, H2/CO2 4.41 and CO2/N2 24.74 and CO2/CH4 18.45 selectivities respectively. The prepared TFN membranes show superior performance to C-MWCNT-based membranes because of their synergetic bonding chemistry and hydrophilic nature. This study has proven that slight addition of functional MWCNTs in polymeric nanocomposite membranes responsible to obtain better performance of the TFN membranes.