Hits:

Indexed by:期刊论文

Date of Publication:2014-08-07

Journal:JOURNAL OF PHYSICAL CHEMISTRY C

Included Journals:SCIE、EI、Scopus

Volume:118

Issue:31

Page Number:17585-17593

ISSN No.:1932-7447

Abstract:A new microporous polyimide network (PI-ADNT) is synthesized from 1,3,5,7-tetrakis(4-aminophenyl)-adamantane and naphthalene-1,4,5,8-tetracarboxylic dianhydride. Subsequently, PI-ADNT is nitrated in fuming nitric acid with different nitration time to produce three nitro-decorated porous polyimides (PI-NO(2)s). Their chemical structures and nitration degrees are characterized by FTIR, solid-state C-13 CP/MAS NMR spectra and element analysis. The interesting evolution of porous morphology and porosity of PI-NO(2)s with nitration time is investigated in detail. The results show that PI-ADNT has the BET surface area of 774 m(2) g(-1) with microporous size centering at 0.75 nm. After nitration-modifications, PI-NO(2)s display decreased surface area but remarkably increased CO2 uptake up to 4.03 mmol g(-1), which is superior to most of porous polymers reported in the literature. Moreover, the CO, adsorption selectivites over CH4 and N-2 in PI-NO(2)s are also significantly improved in comparison with PI-ADNT. The CO2 adsorption/separation properties of PI-ADNT and its nitrated products are studied and explained in terms of the variations of porous structure and chemical composition as well as the interaction parameters between CO2 molecule and polymer skeleton such as Henry's constant, first virial coefficient, and enthalpy of adsorption.