Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2018-06-21

Journal: JOURNAL OF PHYSICAL CHEMISTRY C

Included Journals: SCIE

Volume: 122

Issue: 24

Page Number: 12831-12838

ISSN: 1932-7447

Abstract: Three hyper-cross-linked microporous polybenzoxazoles (PBO-M, PBO-Ad, and PBO-Si) with uniform pores are synthesized through "one-pot" condensation polymerizations from 3,3'-diamino-4,4'-dihydroxybiphenyl with tetrakis(4-formylphenyOmethane, 1,3,5,7-tetrakis(4-formyphenyl)adamantane, and tetrakis(4-formylphenyl)silane, respectively. Their porosity parameters and chemical compositions, such as microporous sizes (0.98-1.46 nm), ratios of microporous volume to total porous volume (0.36-0.53), ratios of O/C (0.156-0.195), and N/C (0.079-0.095), are finely tunable. The adsorption properties of CO2, N-2, and CH4 measured through the static adsorption isotherms of single component gases and dynamic breakthrough curves are comparatively studied. Among the three polymers, PBO-M possesses the smallest pore size and the highest concentrations of heteroatoms, and consequently shows the largest CO2 adsorption capacity (11.6 wt %, 273 K/1 bar) and highest separation factors of CO2/N-2 (96.6) and CO2/CH4 (12.4). The results are interpreted in terms of the porous structure, isosteric enthalpies of adsorption, and the physicochemical parameters of polymer skeletons and gases in detail.