Tan Ke Tian, Tao Shanshan, Huang Ning, Jiang Donglin
Department of Chemistry, Faculty of Science, National University of Singapore, 3, Science Drive 3, Singapore, 117543, Singapore.
Nat Commun. 2021 Nov 19;12(1):6747. doi: 10.1038/s41467-021-27128-4.
Progress over the past decades in water confinement has generated a variety of polymers and porous materials. However, most studies are based on a preconception that small hydrophobic pores eventually repulse water molecules, which precludes the exploration of hydrophobic microporous materials for water confinement. Here, we demonstrate water confinement across hydrophobic microporous channels in crystalline covalent organic frameworks. The frameworks are designed to constitute dense, aligned and one-dimensional polygonal channels that are open and accessible to water molecules. The hydrophobic microporous frameworks achieve full occupation of pores by water via synergistic nucleation and capillary condensation and deliver quick water exchange at low pressures. Water confinement experiments with large-pore frameworks pinpoint thresholds of pore size where confinement becomes dominated by high uptake pressure and large exchange hysteresis. Our results reveal a platform based on microporous hydrophobic covalent organic frameworks for water confinement.
在过去几十年中，水限制方面的进展催生了多种聚合物和多孔材料。然而，大多数研究基于一种先入之见，即小的疏水孔最终会排斥水分子，这阻碍了对用于水限制的疏水微孔材料的探索。在此，我们展示了在结晶共价有机框架中通过疏水微孔通道实现的水限制。这些框架被设计成构成致密、排列整齐且一维的多边形通道，这些通道对水分子开放且可进入。疏水微孔框架通过协同成核和毛细管凝聚实现水对孔隙的完全占据，并在低压下实现快速的水交换。对大孔框架进行的水限制实验确定了孔径阈值，在该阈值下，限制作用由高吸收压力和大的交换滞后主导。我们的结果揭示了一个基于微孔疏水共价有机框架的水限制平台。
