School of Chemistry , Indian Institute of Science Education and Research , Thiruvananthapuram , Kerala 695551 , India.
ACS Appl Mater Interfaces. 2018 May 2;10(17):15183-15188. doi: 10.1021/acsami.8b03150. Epub 2018 Apr 23.
We show that crown ethers (CEs) 1-5 congeal both polar and nonpolar solvents via their self-assembly through weak noncovalent interactions (NCIs) such as CH···O and CH···π interactions. Diisopropylidene-mannitol (6) is a known gelator that self-assembles through stronger OH···O H bonding. These two gelators together also congeal nonpolar solvents via their individual self-assembly. Gelator 6 self-assembles swiftly to fibers, which act as templates and attract CE to their surface through H bonding and thereby facilitate their self-assembly through weak NCI. Polymerization of styrene gels made from CE and 6, followed by the washing off of the sacrificial gelator 6, yields robust porous polystyrene-crown ether hybrid matrices (PCH), having pore-exposed CEs. These PCHs not only were efficient in sequestering alkali metal ions from aqueous solutions but also can be recycled. This novel use of organogels for making solid sorbents for metal-ion scavenging might be of great interest.
我们表明冠醚（CEs）1-5 通过其通过弱非共价相互作用（NCIs）的自组装凝聚极性和非极性溶剂，例如 CH···O 和 CH···π 相互作用。二异丙叉甘露醇（6）是一种已知的凝胶剂，通过更强的 OH···O H 键合自组装。这两种凝胶剂也通过它们各自的自组装共同凝聚非极性溶剂。凝胶剂 6 迅速自组装成纤维，这些纤维作为模板，通过氢键吸引 CE 到其表面，从而促进它们通过弱 NCI 自组装。由 CE 和 6 制成的苯乙烯凝胶的聚合，随后洗掉牺牲性凝胶剂 6，得到坚固的多孔聚苯乙烯-冠醚杂化基质（PCH），具有暴露在孔中的 CE。这些 PCH 不仅有效地从水溶液中隔离碱金属离子，而且还可以回收。这种使用有机凝胶制备用于金属离子清除的固体吸附剂的新方法可能具有很大的兴趣。
