Li Y, Liu J, Kong J, Qi N, Chen Z. Role of ultramicropores in the remarkable gas storage in hypercrosslinked polystyrene networks studied by positron annihilation.
Phys Chem Chem Phys 2021;
23:13603-13611. [PMID:
34114590 DOI:
10.1039/d1cp01867a]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this paper, hypercrosslinked polystyrene (HCLPS) networks were synthesized by radical bulk polymerization and Friedel-Crafts alkylation reactions using vinylbenzyl-co-divinylbenzene chloride (VBC-DVB) as the precursors. A series of HCLPS was prepared with varying content of DVB from 0 to 10% in the precursor. Both N2 adsorption and positron annihilation measurements reveal micropores in the HCLPS. Especially, the existence of ultramicropores with a size in the range of 0.63-0.7 nm is confirmed by positron lifetime measurements. With increasing DVB content from 0 to 10%, the number of ultramicropores shows a gradual increase. Both the H2 and CO2 adsorption capacity increase monotonously with the increase of the DVB content. With 10% DVB in the HCLPS, the H2 storage increases to 10.3 mmol g-1 (2.05 wt%) at 77 K and 1 bar and the CO2 capture reaches 2.81 mmol g-1 (12.4 wt%) at 273 K and 1 bar. The remarkable gas storage ability is ascribed to the existence of the ultramicropores, which result in a stronger affinity to the gas molecules. By using positrons as a new probe for the pores, our results provide convincing evidence of the role of ultramicropores in the gas adsorption performance in microporous organic polymers.
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