Chemical Research in Chinese Universities ›› 2026, Vol. 42 ›› Issue (5): 1449-1460.doi: 10.1007/s40242-026-6177-y

• Research Articles • Previous Articles     Next Articles

Modulation of K+/Na+ Selective Transport Kinetics via Charge and Alkyl Chain Length of Edge-modified Carbon Nanotubes

LIU Rui, ZHANG Cheng, CHEN Rixuan, ZHANG Yuanshuo, YAN Tianjing, CAO Menghao, SONG Yichong, HUANG Menglian, XIA Fan   

  1. State Key Laboratory of Biogeology and Environmental Geology, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China
  • Received:2026-07-13 Accepted:2026-08-23 Online:2026-10-01 Published:2026-09-24
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (Nos. 22090050, U24A20502), the National Key R&D Program of China (No. 2021YFA1200403), and the Natural Science Foundation of Shenzhen, China (No. JCYJ20220530162406014).

Abstract: The respective and coupled contributions of electrostatic charge and steric hindrance at the nanopore entrance to ion transport remain poorly understood. Molecular dynamics simulations were employed to investigate potassium and sodium ion transport through edge-functionalized carbon nanotubes, focusing on how charge and chain length of grafted groups modulate ion permeation. It turns out that positively charged short chains promote chloride transport; strong sodium-chloride pairing drives sodium ions backward while potassium migrates forward, achieving complete spatial separation. For negatively charged groups, a four-state selectivity progression emerges from competition between ion hydration and group coordination. Long chains enhance potassium selectivity by disrupting hydration shells more effectively. This work provides atomic-level design principles for functionalized carbon nanotube ion channels and offers insights into transport mechanisms in confined nanofluidic systems.

Key words: Carbon nanotube (CNT), Molecular dynamics, Real first interface