Fundamental aspects of electric double layer force-distance measurements at liquid-solid interfaces using atomic force microscopy.

ABSTRACT: 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

SUBMITTER: Black JM 

PROVIDER: S-EPMC5009352 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature