Kobayashi K, Oyabu N, Kimura K, Ido S, Suzuki K, Imai T, Tagami K, Tsukada M, Yamada H. Visualization of hydration layers on muscovite mica in aqueous solution by frequency-modulation atomic force microscopy.
J Chem Phys 2013;
138:184704. [PMID:
23676061 DOI:
10.1063/1.4803742]
[Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A three-dimensional interaction force mapping experiment was carried out on a muscovite mica surface in an aqueous solution using a high-resolution and low-thermal drift frequency-modulation atomic force microscope. By collecting oscillatory frequency shift versus distance curves at the mica∕solution interface, complicated hydration structures on the mica surface were visualized. Reconstructed two-dimensional frequency shift maps showed dot-like or honeycomb-like patterns at different tip-sample distances with a separation of 0.2 nm with each other, which agree well to the water molecule density maps predicted by a statistical-mechanical theory. Moreover, site-specific force versus distance curves showed a good agreement with theoretically calculated site-specific force curves by a molecular dynamics simulation. It is found that the first and second hydration layers give honeycomb-like and dot-like patterns in the two-dimensional frequency shift images, respectively, corresponding to the lateral distribution function in each layer.
Collapse