New polysulfone microcapsules containing metal oxides and ([BMIM][NTf2]) ionic liquid for CO2 capture

Abstract

CO2 emission from flue gas is one of the main sources of global warming. The development of new materials with enhanced CO2 adsorption is crucial to foster sustainable development. In this work, 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][NTf2]) ionic liquid (IL) was synthesized and combined to metal oxides (Fe2O3, CuO and TiO2) for further encapsulation in polysulfone (PSF) using emulsification method. Computational study using “ab initio” method was also performed. Scanning electron microscopy evidenced the uniform formation of the IL/metal oxide encapsulated polysulfone microcapsule. Transmission electron microscopy (TEM) and Scanning electron microscopy indicates the formation of microcapsules of around 1.0 μm containing a dense core (IL/metal oxide) when Fe2O3 was encapsulated by a polymer shell presenting better CO2 sorption compared to microcapsule containing CuO and TiO2. Thermogravimetric analysis (TGA) presents microcapsule thermal behavior indicating microcapsule lower degradation temperature when compared to neat PSF. IL encapsulation capacity was determined using acetone immersion test. Results indicated around 40 % of encapsulation capacity. Differential scanning calorimetry shows the complete disappearance of the IL (at -3.14 ℃) characteristic peak after the acetone immersion test confirming IL removal by the method. The residue wt.% calculated by TGA in air atmosphere was used to determine the metal oxide amount incorporated in the microcapsules. The CO2 sorption capacity of microcapsule with Fe2O3 shows an enhancement of around 47 % as compared to the neat-PSF. Here we reported the development of an effective solvent-free adsorbent for CO2 capture fostering industrial application.