What is “Water?”

Everyone must drink water every day. “Water” exists everywhere on the earth and is essential for living creatures to survive. In chemical terms, the water molecule consists of one oxygen atom and two hydrogen atoms. On the earth, H₂O exists in all states: gas (water vapor), liquid (water) or solid (ice or snow), and it is deeply interconnected with our daily lives. Hence, “water” is a well known material for us, but the “properties of water” should never be regarded as “normal.” For example, once water is frozen, it increases its volume and the resulting ice floats on the surface of water. This may seem like nothing special, but in fact, only a few kinds of substances on our planet behave like this. Since ice is lighter than water, fish can survive winter in a pond. In addition, if the force called “hydrogen bonding” never acted on water, or if water molecules (H₂O) had a straight or right-angle shape, water would never exist on the earth. What other “mysteries of water” do you know?

 

What Kind of Research are You Conducting?

We are focusing on the basic properties of H₂O and applying this approach in various areas, as shown below.
<Understanding “life” through H₂O>

Freezing Process of Living Cells

Water is an essential substance for a living creature (an individual) to survive, but how does it function? It is one of the substances that make or help make cells which make up an individual, proteins which function in the cells, and other similar biological components. It is also a transport medium for the exchange of substances or materials in an individual or a cell, and a place for reactions where proteins are produced or transported. Therefore, we consider that we can control the activities of living creatures by controlling “water.”

“Cryopreservation technology” which freezes live cells, for example, is a technology to control the freezing process of water inside or outside a cell. Through the development of a cryopreservation technology on the cells which have been hard to preserve, we are attempting to investigate and explain the relationship between “life” and the freezing process of water inside and outside of a cell.  

Do you also know that inert gas which causes no chemical reaction shows general anesthetic effects on living creatures and paralyzes their consciousness? This phenomenon may be caused by gas molecules inhibiting signals from transmitting among nerve cells. Although the mechanism of the general anesthesia is not revealed yet, we have been conducting experiments with the assumption that it is caused by the change in the state of “water” between or within cells.

“Firey Ice,” Methane Hydrate [1]

<Understanding “energy” through H₂O>
Have you heard about “firey ice?” It is methane hydrate which exists below the deep ocean floor around Japan and is expected to be a natural gas resource in the near future. This substance is a crystal similar to ice, which is formed by the reaction between natural gas in the ocean floor and sea water. We are attempting to clarify where and how much methane hydrate exists on the earth by investigating the characteristics of this substance.

Since the methane hydrate, contains so much methane gas in the solid state, we are also looking at the feasibility of its utilization as a storage and a transport medium for natural gases.
<Understanding the “environment” through H₂O>
Technologies that use “microscopic bubbles” have been developed to clean the contamination of water in lakes, industrial wastewater or similar environments. Bubbles in sodas are large in size, which quickly rise up to the surface and disappear. However, if they are so small that they are invisible to the naked eye, they will rise up more slowly and thus stay within water for a longer time. Since a bubble surface is an interface between gas and water, it may be the place where substrates existing in water can be collected. We are attempting to reveal how the contamination in water can be removed by the introduction of these microscopic bubbles into water solutions, through electron microscope observation.

Impurity Attached to Bubble Surface [2]
(A white bar at lower left indicates 0.1 micrometer.)

<Understanding “molecules and atoms” through H₂O>
The size of an H₂O molecule is as small as one millionth of a millimeter. Even the current electron microscope technology doesn’t allow us to see a single H₂O molecule. As described above, H₂O molecules are connected to our life through their interaction with various substances. Thus, we are trying to develop a special electron microscope to observe a single H₂O molecule. An observation of a single H₂O molecule will help us understand and reveal the many “mysteries of H₂O.”

 

References

[1] “Unconventional Natural Gases – the new leaders of energy resources (coal bed methane, shale gas, and methane hydrate) (Hi Zairai Gata Tennen Gas no Subete),” (Ed. The Editing Committee), Nihon Kyogyo Shuppan, p. 270, 2014.

[2] T. Uchida et al., Nanoscale Research Letters, Vol. 6 (1), p. 295, 2011.

[3] “Dictionary of Snow and Ice (New Version), (Shinban Seppyou Jiten),” (Ed. The Japanese Society of Snow and Ice), Kokon Shoin, p. 307, 2014.

[4] “New Developments on Physics and Chemistry of Ice (Kori no Butsuri to Kagaku no Shintenkai),” (Ed. Institute of Low Temperature Science, Hokkaido University), Low Temperature Science (Teion Kagaku), Vol. 71, p. 192, 2013.