Fabrication of Microporous Aminal-Linked Polymers with Tunable Porosity toward Highly Efficient Adsorption of CO2, H2, Organic Vapor, and Volatile Iodine

• Published in: Industrial & engineering chemistry research Vol. 58; no. 37; pp. 17369 - 17379
• Main Authors: Rong, Meng, Yang, Liangrong, Wang, Li, Xing, Huifang, Yu, Jiemiao, Qu, Hongnan, Liu, Huizhou
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.09.2019
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.9b03126

In this work, a series of microporous aminal-linked polymers (MALPs) are designed and prepared through the polycondensation of 1,4-bis­(2,4-diamino-1,3,5-triazine)-benzene and four rigid tetra-aldehydes such as tetra­(4-formylphenyl)­methane, tetra­(4-formylphenyl)­silane, 1,3,5,7-tetra­(4-formyphenyl)­adamantane and 9,9′-spirobi­[9H-fluorene]-2,2′,7,7′-tetracarboxaldehyde. Benefiting from highly contorted structural units introduced into the polymer network, the nitrogen-rich MALPs exhibit large surface areas (1093–1179 m2/g) and narrow pore size distributions (0.52, 0.93 nm), which endow them with superior small molecules adsorption performances such as CO2, toxic organic vapors, and volatile iodine. It is found that higher amounts of micropores greatly improve the small molecules adsorption performance. For example, among the prepared four MALPs, MALP-2 showed a largest adsorbed amount of 18.6 wt % CO2 (273 K, 1 bar), and high adsorption selectivity of CO2/N2 (22.5) and CO2/CH4 (6.3). Notably, MALP-2 could uptake 35.4 wt % benzene, 30.7 wt % cyclohexane, 35.7 wt % toluene vapors even at 298 K and a very low-pressure of P/P 0 = 0.1, surpassing many other porous organic polymers. MALP-2 also displays an excellent iodine vapor adsorption capacity (218.5 wt %) and remarkable solution iodine adsorption ability. The stable physicochemical properties and excellent adsorption performances toward CO2, toxic organic vapor, and iodine demonstrate that MALPs are promising adsorbents for environmental remediation.