Scientists measured electrical conductivity of pure interfacial water

Skoltech scientists in collaboration with researchers from the University of Stuttgart, the Karlsruhe Institute of Technology and the Russian Quantum Center achieved the first systematic experimental measurements of the electrical conductivity of pure interfacial water, hence producing new results significantly extending our knowledge of interfacial water.

Interfacial water may be found everywhere around us. Biological systems, electrochemical devices, food preservation methods, climate-related processes to name a few, all depend on the properties of water near interfaces. However, direct access to the physical-chemical properties of pure interfacial water is arduous and explains why much remains to be discovered and understood.

The results obtained by the scientists from the Skoltech Center for Energy Science and Technology (CEST) in collaboration with German researchers provide new and detailed insights into complex fluids. The discovery of new electrical properties of interfacial water will clearly have impact on the future development of electrochemical systems, both for electrical power generation and storage.

“We used diamond-based ceramics with open-pore structure filled with water. By consistent reduction of the pore size from 500 nm to 5 nm, we increased the interfacial-to-bulk-water ratio up to its maximum, at which point the interfacial water showed anomalous DC conductivity, five orders of magnitude higher than that of the bulk water. Our analysis shows that this unusual conductivity is a genuine intrinsic property of the interfacial water, as the surface chemistry contribution clearly appears not to be the dominant one,” explains Vasily Artemov, Senior Research Scientist in the group of Skoltech professor Henni Ouerdane.

“The topic of interfacial water is of immense interest to a wide audience of physicists, electrochemists, climate researchers, geologists and biologists, and we anticipate that the research we report will be influential across a diverse range of scientific and technological fields, such as electrochemical energy systems, membrane technologies and nanofluidics,” said Henni Ouerdane.

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The collaborative study was led by Dr. Vasily Artemov who joined professor Ouerdane’s research group in November 2018. Thanks to the strong support from Skoltech, professor Ouerdane and Dr. Artemov succeeded in designing and building the Dielectric Lab Setup at CEST in a record time and producing world-class results. The setup now attracts local and international students for short research stays in the framework of the Global Campus program. Research projects in physical chemistry, materials science, biology and across these disciplines are sure to benefit from the new facility. Professor Ouerdane and Dr. Artemov are set on further fostering the broadband dielectric spectroscopy research at their lab.