Chemical Research in Chinese Universities ›› 2026, Vol. 42 ›› Issue (5): 1444-1448.doi: 10.1007/s40242-026-6168-z

• Research Articles • Previous Articles     Next Articles

Influence of Pore Diameter on Water Transport Through Subnanometer-sized Artificial Channels

HU Yi-Fei1, WANG Yinglan1, LI Jia-Shuo1, XIAO Qi1, ZHANG Meng-Ke1, WANG Wenning1, SUN Mo1, HOU Jun-Li1,2,3   

  1. 1. Department of Chemistry, Fudan University, Shanghai 200438, P. R. China;
    2. State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200438, P. R. China;
    3. Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, P. R. China
  • Received:2026-07-08 Accepted:2026-08-10 Online:2026-10-01 Published:2026-09-24
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (No. 2022YFA1203401), the National Natural Science Foundation of China (Nos. 21921003, 21971046, 22377015, 22174025), and the Project of the Science and Technology Commission of Shanghai Municipality, China (No. 22JC1403700).

Abstract: Water transport under subnanometer confinement exhibits transport behaviors that differ fundamentally from those in larger nanopores, yet how pore diameter governs water permeation remains poorly understood. Here, we report a series of pillar[n]arene-based artificial water channels with systematically varied pore diameters while preserving an otherwise identical channel framework. Unexpectedly, water permeability decreases monotonically with increasing pore diameter, revealing an inverse size dependence under subnanometer confinement. Combined ion-selective transport measurements, ion-water competition experiments, and molecular dynamics simulations reveal that this inverse dependence originates from a pore-diameter-controlled transport regime transition. Rather than directly enhancing water permeation through geometric enlargement, increasing pore diameter lowers the energetic barrier for chloride permeation, thereby activating ion-water competition that suppresses water transport. These findings establish a quantitative structure-transport relationship, in which pore diameter regulates water transport by controlling the onset of chloride permeation, providing mechanistic insights into pore-diameter-dependent transport within this homologous channel series and informing the rational design of high-performance artificial water channels.

Key words: Artificial water channel, Pore diameter, Ion-water competition, Water transport