Abstract: 

Water is essential for living organisms, however its structure and properties are mysterious so far, and thus water is still considered as a sort of knotty subject [1]. One often mentions that water is anomalous because water has the high viscosity, high surface tension, high melting and boiling points compared with other hydrides of oxygen group. However considering its strong hydrogen-bond interaction, it is strange that their values are rather small. The hydrogen-bonding of water molecules or of small water clusters were relatively well-known by quantum mechanical calculations. Water also exhibits anomalous behavior in thin liquid films. Reports indicate that the viscosity of water between two quarts plates separated by several hundred angstroms shows a periodic nature with peaks at every multiple of 15˚C (i.e., 15, 30, 45, and 60˚C) [2]. These behaviors are noted as the Drost-Hansen temperature anomaly [3]. For the anomalous properties, we have considered and proposed theoretically that water resembles a quantum fluid even at high room temperature.

The quantum mechanical model for water is as follows: Molecules in liquid phase typically display thermal motion with the wavelength, defined by,

 .                                                                 (1) 

 The thermal wavelength is the same idea of a matter wave in statistical thermodynamics. The thermal wavelength for water is very small as about 0.2A, so the wave effects were often neglected. However, because of the strong hydrogen-bond interaction of water molecules, liquid water has small free-space. The thermal wavelength decreases a little and the free-space increases a bit with temperature rise. At the temperatures of multiple of 15 ˚C, we have calculated that the size of free-space fits interestingly with the multiple of half integer of thermal wavelength. Thus the thermal motion of water molecules are synchronized at the Dost-Hansen temperatures and this phenomena involve anomalies in some thermodynamic properties in thin or in narrow space.  We applied this idea to heavy water, and estimated the different temperatures that might have the same behaviors.  The temperatures are 19, 32, 44, 56˚C [4].

Assuming that the quantum mechanical idea of thermal wavelength for water is reasonable, when the Drost-Hansen anomalies are found in some other experiments, and the same phenomena are reproduced with heavy water at the estimated different temperatures, one could hardly deny that water exhibits quantum mechanical behavior at room temperature. We carried out several experiments to elucidate this and to find the Drost-Hansen anomaly: We designed a new system for observing the fluidity or viscosity; a system for observing the surface flow on filter paper; a system for observing the Brownian motion of polystyrene spheres of 1 μm size in water using microscope; and a system for analyzing the Laminar flow using HPLC, flowing through a capillary tube. For all systems, the temperature is controlled and maintained accurately. Anomalies are found and the results will be presented.

References

[1] Ball, P.  Nature  52, 291-292, 2008.

[2] Peschel, G.; Aldfinger, K. H.  Naturwiss. 54, 558, 1969.

[3] Drost-Hansen, W.  Cell. Mol. Biol.  47,  865-883, 2001.

[4] Yoon, B. J.  Bull. Kor. Chem. Soc.  24, 1211-1214, 2003.

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