TY - JOUR
T1 - Water and Ion Transfer to Narrow Carbon Nanotubes
T2 - Roles of Exterior and Interior
AU - Neklyudov, Vadim
AU - Freger, Viatcheslav
N1 - Funding Information:
The financial support by a joint grant 2016627 from the United States-Israel Binational Science Foundation (Israel) and National Science Foundation (United States) and by the Planning & Budgeting Committee, Israel Council for Higher Education and Fuel Choice Initiative (Prime Minister Office of Israel) within the framework of “Israel National Research Center for Electrochemical Propulsion (INREP)” is acknowledged. The authors thank Aleksandr Noy and Meni Wanunu for discussions and many valuable suggestions.
Publisher Copyright:
©
PY - 2021/1/14
Y1 - 2021/1/14
N2 - Narrow carbon nanotubes (CNTs) desalinate water, mimicking water channels of biological membranes, yet the physics behind selectivity, especially the effect of the membrane embedding CNTs on water and ion transfer, is still unclear. Here, we report ab initio analysis of the energies involved in transfer of water and K+ and Cl- ions from solution to empty and water-filled 0.68 nm CNTs for different dielectric constants (ϵ) of the surrounding matrix. The transfer energies computed for 1 ≤ ϵ < ∞ permit a transparent breakdown of the transfer energy to three main contributions: binding to CNT, intra-CNT hydration, and dielectric polarization of the matrix. The latter scales inversely with ϵ and is of the order 102/ϵ kJ/mol for both ions, which may change ion transfer from favorable to unfavorable, depending on ion, ϵ, and CNT diameter. This may have broad implications for designing and tuning selectivity of nanochannel-based devices.
AB - Narrow carbon nanotubes (CNTs) desalinate water, mimicking water channels of biological membranes, yet the physics behind selectivity, especially the effect of the membrane embedding CNTs on water and ion transfer, is still unclear. Here, we report ab initio analysis of the energies involved in transfer of water and K+ and Cl- ions from solution to empty and water-filled 0.68 nm CNTs for different dielectric constants (ϵ) of the surrounding matrix. The transfer energies computed for 1 ≤ ϵ < ∞ permit a transparent breakdown of the transfer energy to three main contributions: binding to CNT, intra-CNT hydration, and dielectric polarization of the matrix. The latter scales inversely with ϵ and is of the order 102/ϵ kJ/mol for both ions, which may change ion transfer from favorable to unfavorable, depending on ion, ϵ, and CNT diameter. This may have broad implications for designing and tuning selectivity of nanochannel-based devices.
UR - http://www.scopus.com/inward/record.url?scp=85099031075&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.0c03093
DO - 10.1021/acs.jpclett.0c03093
M3 - Article
C2 - 33325707
AN - SCOPUS:85099031075
VL - 12
SP - 185
EP - 190
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 1
ER -