Surface tuning of silica by deep eutectic solvent to synthesize biomass derived based membranes for gas separation to enhance the circular bioeconomy

Membrane technology and deep eutectic solvents (DESs) have demonstrated their efficient and alterable functionality against environmental pollutants in a cost-effective way. This research focuses on the surface tunning and interface engineering of DES using cetyltrimethylammonium bromide (CTAB) and acetic acid to immobilize on mesoporous silica MCM-41 to mitigate the environmental pollutants. Surface tuned MCM-41 was blended with dope solution of tetrahydrofuran (THF) and polysulfone (Psf) to fabricate uniform composition of mixed matrix membranes (MMMs) for carbon dioxide (CO2) separation as CO2 is a barrier in environment as well as in the industrial applications. The characterization of DES has confirmed the presence of CTAB and acetic acid composition that was physically pasted on silica surface. SEM images disclosed that increasing amount of MCM-DES loading up to 20%, improved its dispersion ability on membrane surface. FTIR analysis revealed that there was no reaction took place among the constituents of MMMs. UTM analysis described the strength reduction in membranes with respect to the increase in percentage of filler loading. MCM provided the porous structure, better pore size distribution and large surface area whereas DES supplied amino and carboxyl functional groups for the attraction of CO2. Blending of MCM-DES filler with Psf led to enhanced selectivity (63–67%) and permeability (70–71%) of CO2 gas than pristine Psf and it was also proved better than pure MCM-41 containing membranes and verified by Robeson plot. Hence, these MMMs are very much suitable to reduce environmental pollutants like CO2 from gaseous biomass like natural gas to improve the circular bioeconomy.