Viscosity and Wetting Property of Water Confined in Extended Nanospace Simultaneously Measured from Highly-Pressurized Meniscus Motion
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- 作者：Lixiao Li ; Yutaka Kazoe ; Kazuma Mawatari ; Yasuhiko Sugii ; Takehiko Kitamori
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2012
- 出版时间：September 6, 2012
- 年：2012
- 卷：3
- 期：17
- 页码：2447-2452
- 全文大小：358K
- 年卷期：v.3,no.17(September 6, 2012)
- ISSN：1948-7185
文摘
Understanding fluid and interfacial properties in extended nanospace (10鈥?000 nm) is important for recent advances of nanofluidics. We studied properties of water confined in fused-silica nanochannels of 50鈥?500 nm sizes with two types of cross-section: (1) square channel of nanoscale width and depth, and (2) plate channel of microscale width and nanoscale depth. Viscosity and wetting property were simultaneously measured from capillary filling controlled by megapascal external pressure. The viscosity increased in extended nanospace, while the wetting property was almost constant. Especially, water in the square nanochannels had much higher viscosity than the plate channel, which can be explained considering loosely coupled water molecules by hydrogen bond on the surface within 24 nm. This study suggests specificity of fluids two-dimensionally confined in extended nanoscale, in which the liquid is highly viscous by the specific water phase, while the wetting dynamics is governed by the well-known adsorbed water layer of several-molecules thickness.