Tetraphenyladamantane-Based Microporous Polyimide and Its Nitro-Functionalization for Highly Efficient CO2 Capture

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• 作者：Changjiang Shen ; Zhonggang Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 7, 2014
• 年：2014
• 卷：118
• 期：31
• 页码：17585-17593
• 全文大小：512K
• ISSN：1932-7455

文摘

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-NO₂s). Their chemical structures and nitration degrees are characterized by FTIR, solid-state ¹³C CP/MAS NMR spectra and element analysis. The interesting evolution of porous morphology and porosity of PI-NO₂s with nitration time is investigated in detail. The results show that PI-ADNT has the BET surface area of 774 m² g^鈥? with microporous size centering at 0.75 nm. After nitration-modifications, PI-NO₂s display decreased surface area but remarkably increased CO₂ uptake up to 4.03 mmol g^鈥?, which is superior to most of porous polymers reported in the literature. Moreover, the CO₂ adsorption selectivites over CH₄ and N₂ in PI-NO₂s 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鈥檚 constant, first virial coefficient, and enthalpy of adsorption.