Physical Properties of Water Near a Gold Surface: A Nanorheological Analysis |
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Authors: | David Mendez Soares Dr Mário Alberto Tenan Dr Andreza Barbosa Gomide Wyllerson Evaristo Gomes |
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Institution: | Laboratory of Nanostructures and Interfaces, Institute of Physics, University of Campinas—UNICAMP, C.P. 6165, 13083‐970, Campinas, SP (Brazil), Fax: (+55)?19 35215376 |
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Abstract: | Water at room temperature is not simply a medium for which uniform properties can always be assumed. Water close to solid hydrophobic or hydrophilic surfaces has elasticity, which is measured by monitoring the quartz crystal microbalance (QCM) resonant frequency and resistance. Small additions of salt are shown to modify this elasticity. Furthermore, near the hydrophobic QCM gold electrode, undersaturated aqueous NaCl solutions present a high concentration of ion pairs, which is confirmed by atomic force microscopy through force versus distance measurements. |
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Keywords: | ion pairs nanorheology quartz crystal microbalance surface chemistry water chemistry |
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