An ionic liquid-decorated layered double hydroxide nanocage ([Hmim][NTf₂]@LDHN) was designed and incorporated into Pebax matrix to fabricate high-performance MMMs for CO₂ separation. The [Hmim][NTf₂] on the external surface, interlamellar spacing, and internal hollow core of LDHN plays cooperative roles with LDHN for improving CO₂ permselectivity. First, the [Hmim][NTf₂] on the external surface of LDHN absorbs more CO₂ molecules than CH₄, improving CO₂/CH₄ selectivity. Then, the captured CO₂ permeates into LDHN shells and are dissolved by [Hmim][NTf₂] in the interlamellar spacing of LDNH. The dissolved CO₂ combines quickly with CO₃²⁻ carriers existed in LDHN itself, accelerating CO₂ transport. Third, the [Hmim][NTf₂] encapsulated in the internal hollow core of the LDHN has an ultrahigh CO₂ capacity, which increases both CO₂ permeability and selectivity. The cooperation of [Hmim][NTf₂] and LDHN significantly enhances CO₂ separation performance. In particular, under humidified conditions the Pebax/[Hmim][NTf₂]@LDHN-6 MMM presents optimal separation performance with a CO₂ permeability of 644 ± 25 Barrer and a CO₂/CH₄ separation factor of 34 ± 0.53, which transcends the upper bound relationship developed by Robeson (2008). The nanofillers combining ILs with nanocages exhibit a promising prospect to fabricate high-performance MMMs for gas separations.

设计了一种离子液体装饰的层状双氢氧化物纳米笼（[Hmim] [NTf ₂ ] @LDHN）并结合到Pebax基质中，以制备用于CO ₂分离的高性能MMM 。LDHN的外表面，层间间距和内部空心的[Hmim] [NTf ₂ ]与LDHN协同作用，以提高CO _2的选择性。首先，LDHN外表面的[Hmim] [NTf ₂ ]比CH ₄吸收更多的CO ₂分子，从而提高了CO ₂ / CH _4的选择性。然后，捕获的CO ₂渗透到LDHN壳中并被[Hmim] [NTf ₂LDNH的层间间距。溶解的CO ₂与LDHN本身中存在的CO ₃ ^2-载体迅速结合，从而加速了CO _2的运输。第三，封装在LDHN的内部空心中的[Hmim] [NTf ₂ ]具有超高的CO ₂容量，从而增加了CO _2的渗透性和选择性。[Hmim] [NTf ₂ ]和LDHN的配合显着增强了CO _2的分离性能。特别是，在潮湿条件下，Pebax / [Hmim] [NTf ₂ ] @ LDHN-6 MMM表现出最佳的分离性能，CO ₂渗透率为644±25 Barrer，CO₂ / CH ₄分离因子为34±0.53，超过了Robeson（2008）提出的上限关系。将IL与纳米笼相结合的纳米填料在制造用于气体分离的高性能MMM方面显示出广阔的前景。