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Abstract Water dynamics inside hydrophobic confinement, such as carbon nanotubes (CNTs), has garnered significant attention, focusing on water diffusion. However, a crucial aspect remains unexplored - the influence of confinement size on water ordering and intrinsic hydrogen bond dynamics. To address this gap, we conducted extensive molecular dynamics simulations to investigate local ordering and intrinsic hydrogen bond dynamics of water molecules within CNTs of various sizes (length:20 nm, diameters: 1.0 nm to 5.0 nm) over a wide range of temperatures (260K, 280K, 300K, and 320K). A striking observation emerged: in smaller CNTs, water molecules adopt an icy structure near tube walls while maintaining liquid state towards the center. Notably, water behavior within a 2.0 nm CNT stands out as an anomaly, distinct from other CNT sizes considered in this study. This anomaly was explained through the formation of water layers inside CNTs. The hydrogen bond correlation function of water within CNTs decayed more slowly than bulk water, with an increasing rate as CNT diameter increased. In smaller CNTs, water molecules hold onto their hydrogen bond longer than larger ones. Interestingly, in larger CNTs, the innermost layer’s hydrogen bond lasts a shorter time compared to the other layers, and this changes with temperature.
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Highly Stable Single Crystals of Three‐Dimensional Porous Oligomer Frameworks Synthesized under Kinetic Conditions
Abstract Various robust, crystalline, and porous organic frameworks based on in situ‐formed imine‐linked oligomers were investigated. These oligomers self‐assembled through collaborative intermolecular hydrogen bonding interactions via liquid–liquid interfacial reactions. The soluble oligomers were kinetic products with multiple unreacted aldehyde groups that acted as hydrogen bond donors and acceptors and directed the assembly of the resulting oligomers into 3D frameworks. The sequential formation of robust covalent linkages and highly reversible hydrogen bonds enforced long‐range symmetry and facilitated the production of large single crystals, with structures that were unambiguously determined by single‐crystal X‐ray diffraction. The unique hierarchical arrangements increased the steric hindrance of the imine bond, which prevented attacks from water molecules, greatly improving the stability. The multiple binding sites in the frameworks enabled rapid sequestration of micropollutant in water.
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- PAR ID:
- 10232274
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 60
- Issue:
- 26
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 14664-14670
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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