Mixed matrix membrane contactor containing core-shell hierarchical Cu@4A filler for efficient SO2 capture

Achieving high flux membrane contactor is significantly important for hazardous gas removal. In this study, we prepared poly(vinylidene fluoride) (PVDF)-based mixed matrix membrane contactor (MMMC) that contained a core-shell hirarchical Cu@4A composite filler (Cu@4A). On one hand, the Cu@4A regulated the physical structure of MMMC, which enhanced gas permeation and thus resulted in the increment of physical SO2 absorption flux. On the other hand, Cu@4A changed the chemical environment of MMMC by remarkably increased SO2 facilitated transport sites, which elevated SO2 concentration around Cu@4A by the enhancement of adsorption and oxidation of SO2, resulting in the increase of chemical SO2 absorption flux. Moreover, the copper nanosheets on 4A helped to construct facilitated transport pathways along the Cu@4A fillers at polymer-filler interface. The results showed that Cu@4A loaded MMMC exhibited increased SO2 removal efficiency and SO2 absorption flux compared with PVDF control membrane. Specifically, the M1040 MMMC loaded with 40 wt% Cu@4A and PVDF concentration 10 wt% exhibited the highest SO2 removal efficiency and SO2 absorption flux, which was up to 73.6% and 9.1 × 10−4 mol·m-2·s-1 at the liquid flow rate of 30 L/h. Besides, the overall SO2 mass transfer coefficient (Ko) and membrane mass transfer resistance (H/Km) were investigated.