School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
ACS Appl Mater Interfaces. 2023 Jun 21;15(24):29468-29477. doi: 10.1021/acsami.3c05398. Epub 2023 Jun 10.
The polypyrene polymer with an extended π-conjugated skeleton is attractive for perfluorinated electron specialty gas (F-gas) capture as the high electronegativity of fluorine atoms makes F-gases strongly electronegative gases. Herein, a polypyrene porous organic framework (termed as Ppy-POF) with an extended π-conjugated structure and excellent acid resistance was constructed. Systematic studies have shown that the abundant π-conjugated structures and gradient electric field distribution in Ppy-POF can endow it exceptional adsorption selectivity for high polarizable F-gases and xenon (Xe), which has been collaboratively confirmed by single-component gas adsorption experiments, time-dependent adsorption rate tests, dynamic breakthrough experiments, etc. Electrostatic potential distribution and charge density difference based on Grand Canonical Monte Carlo simulations and density functional theory calculations demonstrate that the selective adsorption of F-gases and Xe in Ppy-POF is attributed to the strong charge-transfer effect and polarization effect between Ppy-POF and gases. These results manifest that the POF with an extended π-conjugated structure and gradient electric field distribution has great potential in efficiently capturing electron specialty gases.
具有扩展π共轭骨架的聚并苯聚合物因其高电负性氟原子而吸引用于全氟电子特种气体 (F-gas) 的捕获，使 F-gas 成为强电负性气体。在此，构建了具有扩展π共轭结构和优异耐酸性的聚并苯多孔有机骨架（称为 Ppy-POF）。系统研究表明，Ppy-POF 中丰富的π共轭结构和梯度电场分布使其对高极化率的 F-gas 和氙 (Xe) 具有优异的吸附选择性，这已通过单一组分气体吸附实验、时间相关吸附速率测试、动态穿透实验等得到了协同证实。基于巨正则蒙特卡罗模拟和密度泛函理论计算的静电势分布和电荷密度差表明，Ppy-POF 中 F-gas 和 Xe 的选择性吸附归因于 Ppy-POF 与气体之间的强电荷转移效应和极化效应。这些结果表明，具有扩展π共轭结构和梯度电场分布的 POF 在高效捕获电子特种气体方面具有巨大潜力。
