( Ever since the 1970s scientists have b...)UAB scientists discover the origin of a mysterious physical force

Jordi Faraudo, a researcher for the Department of Physics at the Universitat Autònoma de Barcelona, and Fernando Bresme of the Department of Chemistry at Imperial College London have studied this mysterious force in detail and have discovered where its origins lie.

In the same way that a flag flutters in the direction the wind is blowing, at a microscopic level water molecules are gently attracted towards the direction in which an electric field is pointing. However, when the water is in contact with surfaces that create small electric fields, such as chemical compounds like those found in many detergents, this is no longer the case: the water molecules have a remarkable capacity to organise themselves into complex structures that are strongly orientated in such a way as to cancel out the electric field, and on some occasions, to reverse it. This abnormal behaviour was discovered by the same researchers and published in Physical Review Letters in April 2004.

The scientists have now discovered that this strange property is responsible for the hydration force that acts when water is surrounded by certain types of electrostatically charged molecules, such as DNA and some biological compounds, and when thin films form in detergents. The discovery has been published in today's edition of Physical Review Letters.

Water is the solvent in which most physical, chemical and biological processes take place. Therefore, it is essential to understand the nature of interactions between molecules dissolved in water in order to understand many of these processes. Two of the most important of these processes are the adherence of substances to cell membranes and th
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Source:Universitat Autonoma de Barcelona