Liquid Structured on Solid: Piconewton-Mechanics Revealed by AFM
Kobe University
Abstract: Frequency-modulation atomic force microscopy (FM-AFM) provides a promising tool to observe the solid topography and also liquid structure at liquid-solid interfaces. The cantilever with a tip is mechanically oscillated. Force pushing or pulling the tip shifts the resonance frequency of the oscillation. Microscopes with force sensitivity of 10 pN or better in water have been developed and commercialized to date. In this review, Two-dimensional Δf distribution observed on water-calcite is interpreted with Gibbs free energy distribution perturbed by the calcite surface. Δf distributions on hydrophobic and hydrophilic materials are also shown.
Key words: Frequency-Modulation Atomic Force Microscopy, Solid-Liquid Interface, Liquid Structure, Calcite, Molecular Monolayer