Nanocomposites and nanomaterials

Formation of the electrical double layer on the surface of nanoparticles of zirconia with changes in humidity 
Shylo A.V.1, Danilenko I.A.1, Gorban O.A.1,  Doroshkevich A.S.1,2, Lyubchyk A.I.3, Konstantinova T.E.1
1 Materials Science Department, Donetsk Institute for Physics and Engineering named after O.O. Galkin of the NAS of Ukraine, Nauki ave, 46, Kyiv-03028, Ukraine,  e-mail:art.shylo@gmail.com
2Joint Institute for Nuclear Research, 141980, str. Joliot-Curie, 6, Dubna, Russia
3 i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, New University of Lisbon and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica, Portugal
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Nanopowders based on zirconia due to their high dispersion are prone to adsorption of water from the surrounding atmosphere and formation a layer of adsorbed water on the surface of nanoparticles. Therefore, taking into account the processes of formation of adsorbed layers of water on the surface of nanoparticles in real atmospheric conditions, their structure and characteristics, as well as their impact on the structure and electrophysical properties of zirconia nanoparticles are very interesting.
The influence of the degree of hydration on the electrophysical properties of compacted hydrated nanoparticles of zirconia was investigated and a quantitative layer-by-layer model of the hydrated particle was constructed, the number and order of adsorbed water layers on the surface of nanoparticles at different ambient humidity were determined.
The presence of three relaxation processes in the system nanoparticle – adsorbed water layer was established, which indicates different mobility of water molecules in the adsorbed layer and corresponds to its three components - Stern layer, diffuse layer and free water layer in the space between particles. Increasing the degree of hydration of the compacted powder from zero to the most water-saturated leads to sequential filling of the adsorbed layer on nanoparticles, which leads to an increase in electrical capacity of the respective components of the adsorbed layer for the Stern layer in 13 times and for the free water layer in 15 times.
Based on the known model of the structure of the electric double layer and obtained data, the parameters of the electric double layer of nanoparticles was calculated.