Water-ion permselectivity of narrow-diameter carbon nanotubes

Yuhao Li; Zhongwu Li; Fikret Aydin; Jana Quan; Xi Chen; Yun-Chiao Yao; Cheng Zhan; Yunfei Chen; Tuan Anh Pham; Aleksandr Noy

doi:10.1126/sciadv.aba9966

Water-ion permselectivity of narrow-diameter carbon nanotubes

Sci Adv. 2020 Sep 16;6(38):eaba9966. doi: 10.1126/sciadv.aba9966. Print 2020 Sep.

Authors

Yuhao Li¹, Zhongwu Li^{1

2}, Fikret Aydin³, Jana Quan¹, Xi Chen^{1

4}, Yun-Chiao Yao^{1

4}, Cheng Zhan³, Yunfei Chen², Tuan Anh Pham⁵, Aleksandr Noy^{6

4}

Affiliations

¹ Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
² Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189, China.
³ Quantum Simulations Group, Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
⁴ School of Natural Sciences, University of California Merced, Merced, CA 94343, USA.
⁵ Quantum Simulations Group, Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. pham16@llnl.gov noy1@llnl.gov.
⁶ Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. pham16@llnl.gov noy1@llnl.gov.

Abstract

Carbon nanotube (CNT) pores, which mimic the structure of the aquaporin channels, support extremely high water transport rates that make them strong candidates for building artificial water channels and high-performance membranes. Here, we measure water and ion permeation through 0.8-nm-diameter CNT porins (CNTPs)-short CNT segments embedded in lipid membranes-under optimized experimental conditions. Measured activation energy of water transport through the CNTPs agrees with the barrier values typical for single-file water transport. Well-tempered metadynamics simulations of water transport in CNTPs also report similar activation energy values and provide molecular-scale details of the mechanism for water entry into these channels. CNTPs strongly reject chloride ions and show water-salt permselectivity values comparable to those of commercial desalination membranes.

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