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Few studies have been conducted on the effect of nonamine groups on the nanopore environment and gas adsorption/separation ability of normal spherical hyper-crosslinked resins. Here, hyper-crosslinked resins (HCP@COOH and HCP@CO), modified with a COOH-containing structure (A) and a CO-containing structure (B), were synthesized by the Friedel–Crafts acylation reaction. According to static adsorption and dynamic separation tests, different oxygen-containing groups have different impacts on the nanopore diameter and small gas adsorption/separation behavior. Structure (A), benefiting from its suitable nanoscale size, was verified to be effective in narrowing the size of nanopores to 1–2 nm and increasing the adsorption capacity of CO2, CH4, and CO, while Structure (B) seems to have a positive influence only on CH4. The uptake of CO2 and the separation ratio of CO2/CO in HCP@COOH reach 32 cm3/g and 12.2, respectively, at 298 K and 1 bar. The IAST selectivity of CH4/CO in HCP@O-1 is up to 3.4, increasing from 1.9 for HCP-1. HCP@COOH can separate syngas efficiently at ambient temperature and can be regenerated by simple vacuum operation. The interaction mechanism was also analyzed by experiments and electrostatic potential simulation. [ABSTRACT FROM AUTHOR]

Four nonfluorinated and fluorinated nanoporous polymers [PAN-5H, PAN-5F, PAN-2F, and PAN-2-(CF3)] were synthesized from a triazine-based tetramine with benzaldehyde, pentafluorobenzaldehyde, 3,5-difluorobenzaldehyde, and 3,5-bis-(trifluoromethyl)-benzaldehyde, respectively. It is interestingly found that the porosity parameters and selective adsorptions of CO2 and light hydrocarbons strongly depend not only on the number and kind of fluorine atoms and fluorinated groups, but also on the substituted position on the phenyl rings in the fluorinated porous polymers. Relative to PAN-5H and PAN-5F, PAN-2F, and PAN-2-(CF3) with phenyls meta-substituted by two fluorinated groups exhibit considerably increased BET surface areas from 502 to 1269 m2/g. At 298 K and 1 bar, the uptakes of C3H8, C2H6, and C2H4 in PAN-2F reach 4.62, 3.64, and 3.20 mmol/g, respectively, whereas PAN-5F exhibits the highest adsorption selectivities of C3H8/CH4 (372.3), C3H8/CO2 (33.2), C2H6/CH4 (21.8), C3H8/C2H6 (9.4), and CO2/CH4 (7.1) among the four polymers. The dynamic breakthrough experiments demonstrate that the mixed gases of C2H6/C2H4, C3H8/CH4, C2H6/CH4, and CO2/CH4 can be separated by the fluorinated polymers under ambient condition. The achieved results are significant for understanding the effects of fluorine-functionalization on the separation of ethylene and CO2 from light hydrocarbons in nanoporous polymers. [ABSTRACT FROM AUTHOR]

Polymerization confined to the pore was first adapted for the nanoscale structure adjustment of adsorption resin. The self-cross-linked polymer (P-1) formed in the pore of hyper-cross-linked resin (HR) by the Friedel-Crafts reaction of p-dichloroxylene (p-DCX), occupying the macropore of the HR resin and bringing about an external micropore. Compared with the raw HR resin, the volume of the micropore of HR@P-1 in 0.4 < D < 1 nm increased but the volume of the macropore has obviously decreased. After the loading of P-1 in the nanopore of HR, HR@P-1 has better gas adsorption performance. At 298 and 100 KPa, the adsorption capacity of CO 2 is almost 30% higher than that of HR, reaching 35.7 cm 3 /g, due to the increase in the smaller micropore volume. Moreover, HR@P-1 has also been found to be the first C 2 H 6 -selective adsorption resin. The uptake of C 2 H 6 is up to 56 cm 3 /g, and the IAST selectivity of C 2 H 6 /CH 4 reaches 15.3. HR@P-1 can also separate syngas efficiently at ambient temperature and be regenerated by simple vacuum operation.