Hyper-crosslinked aromatic polymers with improved microporosity for enhanced CO2/N2 and CO2/CH4 selectivity†
Hypercrosslinked polymers for selective CO2 capture have been successfully synthesized from highly rigid contorted blocks via a low-cost versatile strategy. Such amorphous materials with improved porosities achieve high specific surface areas of up to 1616 m2 g−1 and substantially improved pore volumes (1.53 cm3 g−1). The polymer networks feature hierarchically porous structures ranging from ultramicropores to mesopores (0.50 to 3.80 nm) as well as high physicochemical stability. They can uptake 15.9 wt% CO2 at 273 K/1 bar, surpassing nearly all polymers of intrinsic microporosity (PIMs) and most known hypercrosslinked polymers (HCPs). The abundant ultramicropores with pore diameters centered at around 0.50 nm allow selective CO2 uptake against N2 (ideal selectivity: 69.7) and CH4 (15.8). These results are significant for molecular design and emphasize the importance of utilizing rigid contorted blocks to build hierarchically porous networks for effective CO2 capture applications.