Visiting Tartu in November

A list of things to bring with you:

  • Gloves, hat and scarf (the average temperature is −1.5°C)
  • Waterproof boots or trekking boots (with a good grip in case there is ice)
  • Layered clothing (like pullovers and cardigans, so that you can remove or add layers according to the weather and how fast you are moving)
  • Swimming equipment (for SPA and sauna or why not doing some winter swimming?)
  • Napkins for a runny nose
  • A postcard to pin in the office 5072 where Vladislav works

Bird’s-eye View

Most of us work on the “dark” side of Chemicum. Meeri is from the “rusted” Physicus (on the back plan), where they have a nice sauna.

From left to right: A, B, C and D wings of Chemicum ( A is for lobby and cateen, B is for lecture halls, C and D are for offices and laboratory. On the back plan there is Physicum (
We are in the upper left corner of the middle-part of Chemicum.

Cool Science & Technology Bachelor’s programmes in English

Do you want to become a next generation creative scientist or engineer? The University of Tartu provides an excellent opportunity! See here The application deadline is 15th of April.

Margaret Fomenko visited us to learn more about the programme. Here is what she thinks: “I fell in love with Tartu since first second I saw it. Small city with it’s history and close-knit community attracts to consider studying. Moreover, I liked the program Tartu university offers, science and technology. It covers various fields of science, like programming, biology and chemistry and allows to make research on interesting topics in modern laboratories.”

Sergey Sosnin’s visit to Tartu

I was in a three-days academic trip in December 2016 within a collaboration between Skoltech research group of Prof. Maxim Fedorov and Tartu theoretical electrochemistry group. My primary goal was to study 3D-RISM method for calculation of the solvatation of molecules and applying this method in my QSAR researches. During my visit I’ve worked closely with Maksim Mišin. He has trained me the 3D-RISM methodology, workflow, and theoretical background. After that we have done a small project related with application of RISM in deep learning for chemoinformatics tasks. I was inspired by good theoretical and practical skills of researchers in the theoretical electrochemistry group. We discussed a lot about current science challenges, and I hope that mutual exchange of ideas was helpful for both.

Because it was my first visit to Tartu I had have intended to familiarize myself with this town. Maksim Mišin and Dr. Vladislav Ivaništšev have represented me this city and have told me a lot of interesting things about Estonia. I was really enjoyed in this trip, and I hope that I will visit it again.

Sergey Sosnin

STSM to Trieste: Simulation of surface charge effect on the sliding friction of a nanoconfined ionic liquid

The interest towards using ionic liquids as lubricants has been increasing since ca. 2012 [1]. It was demonstrated that the interfacial structures in ionic liquids control the nanoscale friction. Experimental (see refs in [1]) and several computational studies [2–5] revealed that lubricity varies with the number and lateral structure of confined ion layers, which in turn are dependent on the applied potential. This opens a possibility of electrochemical control of friction, in other words a “Tantalizing prospect of tunning friction on small dimensions without changing surfaces with a self-replenish­ing layer, and could be easily integrated into niche situations, … because ionic liquids are cheaper than existing nonconducting molecular lubricants” (see refs in [1]). At the same time it was shown that the restructuring of the potential dependent interfacial structure happens in ionic liquids on a regular manner [6,7]. Therefore, there is a direct relation between various interfacial properties through the potential dependent interfacial structure [8]. For instance, it has not been marked in the literature that the potential dependent friction force [9–11] is proportional to the potential dependent capacitance [12–14]. The understanding of this structure-based relationship can help in controlling of the nanoscale friction in ionic liquids by a potential-tuned ionic lubricant layer.

During this STSM visit, we have initiated a comprehensive study: formulated a hypothesis, prepared a research plan, and obtained preliminary results. The later reveal a proportionality between potential dependent capacitance and friction force. Such structure-based relationship can be of use in controlling of the nanoscale friction in ionic liquids by an applied potential. Further work should verify the generic mechanism of the electrotunable lubricity and capacity. In the future study we plan to perform a detailed atomistic simulation to enable comparison between specific computational and experimental data.

This research was supported by a short term scientific mission funded by COST action MP1303.


[1] R. Hayes, G.G. Warr, R. Atkin, Structure and Nanostructure in Ionic Liquids, Chem. Rev. 115 (2015) 6357–6426.

[2] R. Capozza, A. Vanossi, A. Benassi, E. Tosatti, Squeezout phenomena and boundary layer formation of a model ionic liquid under confinement and charging, J. Chem. Phys. 142 (2015) 64707.

[3] R. Capozza, A. Benassi, A. Vanossi, E. Tosatti, Electrical charging effects on the sliding friction of a model nano-confined ionic liquid, The Journal of Chemical Physics. 143 (2015) 144703.

[4] O.Y. Fajardo, F. Bresme, A.A. Kornyshev, M. Urbakh, Electrotunable Lubricity with Ionic Liquid Nanoscale Films, Sci. Rep. 5 (2015) 7698.

[5] O.Y. Fajardo, F. Bresme, A.A. Kornyshev, M. Urbakh, Electrotunable Friction with Ionic Liquid Lubricants: How Important Is the Molecular Structure of the Ions?, The Journal of Physical Chemistry Letters. 6 (2015) 3998–4004.

[6] V. Ivaništšev, K. Kirchner, T. Kirchner, M.V. Fedorov, Restructuring of the electrical double layer in ionic liquids upon charging, J. Phys.: Condens. Matter. 27 (2015) 102101.

[7] V. Ivaništšev, S. O’Connor, M.V. Fedorov, Poly(a)morphic portrait of the electrical double layer in ionic liquids, Electrochem. Commun. 48 (2014) 61–64.

[8] M.V. Fedorov, A.A. Kornyshev, Ionic liquids at electrified interfaces, Chem. Rev. 114 (2014) 2978–3036.

[9] J. Sweeney, F. Hausen, R. Hayes, G.B. Webber, F. Endres, M.W. Rutland, R. Bennewitz, R. Atkin, Control of Nanoscale Friction on Gold in an Ionic Liquid by a Potential-Dependent Ionic Lubricant Layer, Phys. Rev. Lett. 109 (2012) 155502.

[10] H. Li, R.J. Wood, M.W. Rutland, R. Atkin, An ionic liquid lubricant enables su­perlubricity to be “switched on” in situ using an electrical potential, Chem. Com­mun. 50 (2014) 4368–4370.

[11] H. Li, M.W. Rutland, R. Atkin, Ionic Liquid Lubrication: Influence of Ion Structure, Surface Potential and Sliding Velocity, Phys. Chem. Chem. Phys. 15 (2013) 14616–14623.

[12] M. Drüschler, N. Borisenko, J. Wallauer, C. Winter, B. Huber, F. Endres, B. Roling, New insights into the interface between a single-crystalline metal elec­trode and an extremely pure ionic liquid: slow interfacial processes and the influ­ence of temperature on interfacial dynamics, Phys. Chem. Chem. Phys. 14 (2012) 5090–5099.

[13] R. Atkin, N. Borisenko, M. Drüschler, S.Z. El Abedin, F. Endres, R. Hayes, B. Huber, B. Roling, An in situ STM/AFM and impedance spectroscopy study of the extremely pure 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophos­phate/Au(111) interface: potential dependent solvation layers and the herringbone reconstruction, Phys. Chem. Chem. Phys. 13 (2011) 6849.

[14] R. Costa, C.M. Pereira, A.F. Silva, Charge Storage on Ionic Liquid Electric Double Layer: The Role of the Electrode Material, Electrochim. Acta. 167 (2015) 421–428.

STSM to Vienna: MD simulations of ionic liquid mixtures with polarizable force fi elds

Generic force fields are widely used in molecular level computations. However, in real physical systems, the magnitude and localization of the charges are variable due to the interatomic polarization and the molecular dynamics. There are two ways to take these into account: (i) to reduce the atomic charges to non-integer values or (ii) to include polarizableforces.

In this STSM the latter method was used adding Drude oscillators to the system to add the polarizability to the particles. The polarizable force fields (FFs) developed by the group of Prof. Schroder where used to simulate the mixtures of ionic liquids with classical molecular dynamics. Namely mixture of [EMIm][BF4] and [EMIm]I was used. For comparison, the same system with non-polarizable FFs and the system of pure [EMIm][BF4] using polarizable FFs were simulated.

The main problem with classical MD simulations of ions is that the viscosity is overestimated which comes from the fact of imprecise non-bonding interactions. The polarizable FFs estimate it better and taken from the simulations the diffusion constant for the same system with polarizable FFs was much higher than for non-polarizable (1.03 A2/ns and 0.48 A2/ns respectively for cations). The system of pure [EMIm][BF4] showed that iodine affects the movement of ions as the diffusion constant differs by 10% (1.15 A2/ns for cations in pure system). All in all, the polarizable FFs improves the system and adding the small amount of iodine does not change the diffusion nor the structure that much.