Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy
Atomic force microscopy (AFM) force-distance measurements are used to investigate the layered ion structure of Ionic Liquids (ILs) at the mica surface. The effects of various tip properties on the measured force profiles are examined and reveal that the measured ion position is independent of tip pr...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Online |
| Language: | English |
| Published: |
Nature Publishing Group
2016
|
| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5009352/ |
| id |
pubmed-5009352 |
|---|---|
| recordtype |
oai_dc |
| spelling |
pubmed-50093522016-09-12 Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy Black, Jennifer M. Zhu, Mengyang Zhang, Pengfei Unocic, Raymond R. Guo, Daqiang Okatan, M. Baris Dai, Sheng Cummings, Peter T. Kalinin, Sergei V. Feng, Guang Balke, Nina Article Atomic force microscopy (AFM) force-distance measurements are used to investigate the layered ion structure of Ionic Liquids (ILs) at the mica surface. The effects of various tip properties on the measured force profiles are examined and reveal that the measured ion position is independent of tip properties, while the tip radius affects the forces required to break through the ion layers as well as the adhesion force. Force data is collected for different ILs and directly compared with interfacial ion density profiles predicted by molecular dynamics. Through this comparison it is concluded that AFM force measurements are sensitive to the position of the ion with the larger volume and mass, suggesting that ion selectivity in force-distance measurements are related to excluded volume effects and not to electrostatic or chemical interactions between ions and AFM tip. The comparison also revealed that at distances greater than 1 nm the system maintains overall electroneutrality between the AFM tip and sample, while at smaller distances other forces (e.g., van der waals interactions) dominate and electroneutrality is no longer maintained. Nature Publishing Group 2016-09-02 /pmc/articles/PMC5009352/ /pubmed/27587276 http://dx.doi.org/10.1038/srep32389 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Black, Jennifer M. Zhu, Mengyang Zhang, Pengfei Unocic, Raymond R. Guo, Daqiang Okatan, M. Baris Dai, Sheng Cummings, Peter T. Kalinin, Sergei V. Feng, Guang Balke, Nina |
| spellingShingle |
Black, Jennifer M. Zhu, Mengyang Zhang, Pengfei Unocic, Raymond R. Guo, Daqiang Okatan, M. Baris Dai, Sheng Cummings, Peter T. Kalinin, Sergei V. Feng, Guang Balke, Nina Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| author_facet |
Black, Jennifer M. Zhu, Mengyang Zhang, Pengfei Unocic, Raymond R. Guo, Daqiang Okatan, M. Baris Dai, Sheng Cummings, Peter T. Kalinin, Sergei V. Feng, Guang Balke, Nina |
| author_sort |
Black, Jennifer M. |
| title |
Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| title_short |
Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| title_full |
Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| title_fullStr |
Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| title_full_unstemmed |
Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| title_sort |
fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy |
| description |
Atomic force microscopy (AFM) force-distance measurements are used to investigate the layered ion structure of Ionic Liquids (ILs) at the mica surface. The effects of various tip properties on the measured force profiles are examined and reveal that the measured ion position is independent of tip properties, while the tip radius affects the forces required to break through the ion layers as well as the adhesion force. Force data is collected for different ILs and directly compared with interfacial ion density profiles predicted by molecular dynamics. Through this comparison it is concluded that AFM force measurements are sensitive to the position of the ion with the larger volume and mass, suggesting that ion selectivity in force-distance measurements are related to excluded volume effects and not to electrostatic or chemical interactions between ions and AFM tip. The comparison also revealed that at distances greater than 1 nm the system maintains overall electroneutrality between the AFM tip and sample, while at smaller distances other forces (e.g., van der waals interactions) dominate and electroneutrality is no longer maintained. |
| publisher |
Nature Publishing Group |
| publishDate |
2016 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5009352/ |
| _version_ |
1613642060557975552 |