Novel polyethylene glycol/nanosilica Reinforced Polyurethane mixed matrix nanocomposite membrane with enhanced gas separation properties

Abstract

AbstractIn this study, the effect of nanosilica (SiO2) reinforcement on the gas separation properties of polyurethane/polyethylene glycol (PU-PEG) nanocomposite membrane was investigated. Formulation optimization of PU-PEG-SiO2triple nanocomposite membrane was performed using experimental design and the Taguchi method. The effects of different formulation variables including nanosilica content, PEG content and molecular weight on the permeability and selectivity of CO2, N2, O2and CH4gases were investigated. The morphological and structural properties of the membranes were investigated by SEM, XRD, and FTIR analysis. Finally, the selectivity of optimal nanosilica-reinforced membrane was evaluated by Robeson's upper bound diagram. The obtained results showed that increasing the PEG content improves the gas permeability of the membrane due to its plasticizing effect. However, PEG plasticizing effect decreased at higher molecular weights and resulted in permeability reduction. By increasing the nanosilica content, the permeability of all the gasses reduced but the selectivity of the membrane for CO2over CH4and N2improved. Finally, PU-20% PEG6000-5% SiO2formulation which had the best selectivity for CO2/CH4gases and was closer to Robeson’s upper bound line was chosen as the optimal composition. In conclusion, PEG/nanosilica-reinforced Polyurethane nanocomposite membrane could serve as a promising candidate for efficient gas separation applications.