Micro- and mesoporous poly(Schiff-base)s constructed from different building blocks and their adsorption behaviors towards organic vapors and CO<sub>2</sub>gas
作者:Guiyang Li、Biao Zhang、Jun Yan、Zhonggang Wang
DOI:10.1039/c4ta04429k
日期:——
Four porous poly(Schiff-base)s, PSN-DA, PSN-TAPB, PSN-TAPA and PSN-TAPM, are synthesized via one-pot condensation from 1,3,5,7-tetrakis(4-formylphenyl)adamantane with rod-like m-phenyldiamine, triangular 1,3,5-tris(4-aminophenyl)benzene and tris(4-aminophenyl)amine as well as tetrahedral tetrakis(4-aminophenyl)methane, respectively. It is found that the variation of the geometrical shape of the building blocks significantly alters the surface areas, pore sizes and distributions of the resultant porous polymers and thereby remarkably influences their adsorption behaviors towards organic vapors and CO2 gas. PSN-DA, PSN-TAPB and PSN-TAPA are microporous materials with pore sizes of 0.72, 0.95 and 1.04 nm, whereas PSN-TAPM is a micro- and mesoporous material with the major pores centered at 0.86 and 2.62 nm, respectively. Their BET surface areas are in the range from 419 to 1045 m2 g−1. At P/Po = 0.9 and 298 K, PSN-DA possesses high uptakes for both aromatic vapor (benzene, 86.1 wt%) and aliphatic vapor (cyclohexane, 77.9 wt%). In addition, the adsorption and desorption isotherms of CO2 gas in the four porous polymers are reversible – a characteristic which is convenient for the regeneration of CO2 adsorbents. Their adsorption capacities of CO2 are up to 15.0 wt% (273 K/1 bar) with the ideal selectivities of CO2/N2 and CO2/CH4 up to 71 and 14, respectively. showing potential applications in the removal of toxic organic vapors and capture of CO2 from air.
通过一步缩聚反应合成了四种多孔聚席夫碱PSN-DA(棒状)、PSN-TAPB(三角形)、PSN-TAPA(三角形)和PSN-TAPM(四面体),以1,3,5,7-四(4-醛基苯基)金刚烷为连接体单元,分别与棒状间苯二胺、三角形1,3,5-三(4-氨基苯基)苯、三(4-氨基苯基)胺及四面体四(4-氨基苯基)甲烷反应制得。研究发现:构筑单元的几何形状的变化显著改变了所得多孔聚合物的比表面积、孔径大小及分布,并由此明显影响其对有机蒸气和CO2的吸附行为。PSN-DA、PSN-TAPB和PSN-TAPA均为微孔材料,孔径分别为0.72、0.95和1.04 nm;而PSN-TAPM是微孔-介孔复合材料,主要孔径分别为0.86和2.62 nm。它们的比表面积在419~1045 m2·g-1之间。在P/Po=0.9和298 K,PSN-DA对芳香族蒸气(苯,86.1 wt%)及脂肪族蒸气(环己烷,77.9 wt%)均具有高的吸附量。此外,CO2在这四种多孔聚合物中的吸附和脱附等温线呈可逆特性——这使得CO2吸附剂易于再生。它们的CO2吸附容量高达15.0 wt%(273 K/1 bar),并且对CO2/N2和CO2/CH4的理想选择性高达71和14,表明它们在有毒有机蒸气去除和CO2捕获方面具有潜在应用。