Chargée de Recherche CNRS (Section 5), HDR
Research keywords : microscopic dynamics, confinement, liquids and ionic solutions, hydrogels, polyelectrolytes, clay colloids, colloidal aggregation, ion specific effects, neutron and X-ray scattering, MD simulations, NMR spectroscopy and relaxometry
Research topics
1. Counterion specific effects in polyelectrolyte solutions and gels
Ionene polyelectrolytes (cationic polyelectrolytes based on quaternary ammonium centers) show remarkable counterion-specific effects in aqueous solution. Depending on the polarizability and hydration energy of the compensating anions, we can tune the chain conformation as well as the chain-chain interactions in aqueous solution. We explore the consequence of these effects on the multi-scale dynamics of ionene chains, both in solution and in ionene-based gels.
2. Flocculation of clays by organic polyions
Flocculation is a key process in numerous environmental and industrial technologies such as purification of waste water, paper making, food conditioning and cosmetics. Its tuning is of utmost importance in the optimization of the associated industrial protocols.
Our current emphasis is on flocculation in ionene-clay particle suspensions and how to tune the structure of the elementary clay aggregate (tactoid) via the relative charge densities of the ionene chain and the clay particle.
3. Behaviour of water and ions confined in clays
Compacted clay grains are used as one of the protective layers around a radioactive waste package stored underground. Even if compacted, each clay grain (a highly regular stack of crystalline aluminosilicate layers) retains its microporosity, in which water molecules and ions molecules are confined to a quasi-planar geometry, but retain a certain mobility. Studying water and ion dynamics in the microporosity helps to understand the macroscopic penetrability of the clay protective layer.
Teaching
1) University of Poitiers, Erasmus Mundus Master – International Master in Advanced Clay Science, Module « Molecular Modelling », lectures and examples classes at level Master 1 (2009 – now)
2) ECE Paris Ecole d’Ingenieurs, Module “Chemistry” – thermodynamics, reaction kinetics, equilibrium, electrochemistry ; lectures and examples classes at level Master 1 (2012)
3) Laboratoire Leon Brillouin, Programme HERCULES (Higher European Research Course for Users of Large Experimental Systems) / Fan du LLB (French course on Neutron scattering – hands on experiments) ; practicals at post-graduate level (2009, 2010, 2012)
Selected publications
1) Y. Sakhawoth, L. Michot, P. Levitz, A.-L. Rollet, J. Sirieix-Plenet, D. Hermida Merino and N. Malikova, Aggregation of plate-like colloids induced by charged polymer chains : organisation at the nanometer scale tuned by polymer charge density , Langmuir 35 (2019), 10937-10946.
2) T. Janc, M. Luksic, V. Vlachy, B. Rigaud, A.-L. Rollet, J.-P. Korb, G. Meriguet and N. Malikova, Ion-specificity and surface water dynamics in protein solutions, Phys. Chem. Chem. Phys. 20 (2018), 30340.
3) Y. Sakhawoth, L. J. Michot, P. Levitz and N. Malikova, Flocculation of clay colloids induced by model polyelectrolytes – effects of relative charge density and size, Chem Phys Chem 18 (19) (2017), pp. 2756-2765.
4) J. Ballah, M. Chamerois, S. Durand-Vidal, N. Malikova, P. Levitz and L. J. Michot, Effect of chemical and geometrical parameters influencing the wettability of smectite clay films. Colloids and Surfaces A : Physicochemical and Engineering Aspects 511 (2016), pp. 255 – 263.
5) M. Druchok, N. Malikova, A.-L. Rollet, V. Vlachy, Counter-ion binding and mobility in the presence of hydrophobic polyions – combining molecular dynamics simulations and NMR, AIP Advances (American Institute of Physics) 6 (6), (2016) pp.065214.
6) N. Malikova, A.-L. Rollet, S. Cebasek, M. Tomsic and V. Vlachy, On the crossroads between current polyelectrolyte theory and counterion-specific effects, Phys. Chem. Chem. Phys., 17 (2015) pp. 5650-5658.
7) D. Bhowmik, N. Malikova, G. Meriguet, O. Bernard, J. Teixeira and P. Turq, Aqueous solutions of tetralkylammonium halides : ion hydration, dynamics and ion-ion interactions in light of steric effects, Phys. Chem. Chem. Phys., 16 (2014) 13447-13457.
8) V. Marry, E. Dubois, N. Malikova, J. Breu and W. Häussler, Anisotropy of water dynamics in clays : insights from molecular simulations for experimental QENS analysis, J Phys Chem C, 117 (2013) 15106-15115.
9) A. Slodczyk, Ph. Colomban, N. Malikova, O. Zaafrani, S. Longeville, J.-M. Zanotti, O. Lacroix, B. Sala, Bulk protons in anhydrous perovskites – neutron scattering studies, Solid State Ionics, 252 (2013) 7-11.
10) N. Malikova, S. Cebasek, V. Glenisson, D. Bhowmik, G. Carrot and V. Vlachy, Aqueous solutions of ionenes : interactions and counterion specific effects as seen by neutron scattering, Phys. Chem. Chem. Phys., 14 (2012) 12898-12904.
11) D. Bhowmik, N. Malikova, J. Teixeira, G. Mériguet, O. Bernard, P. Turq and W. Häussler, Study of tetrabutylammonium bromide in aqueous solution by neutron scattering, Eur. Phys. J. – Special Topics, 213 (2012) 303-313.
12) V. Marry, E. Dubois, N. Malikova, S. Durand-Vidal, S. Longeville and J. Breu, Water dynamics in hectorite clays : influence of temperature studied by coupling Neutron Spin Echo and Molecular Dynamics, Environmental Science and Technology, 45 (2011) 2850-2855.
12) N. Malikova, S. Longeville, J.-M. Zanotti, E. Dubois, V. Marry, P. Turq, J. Ollivier, Signature of low dimensional motion in complex systems, Phys. Rev. Lett., 101 (2008) 265901.
13) N. Malikova, C.-K. Loong, J.-M. Zanotti et F. Fernandez-Alonso, Proton-containing yttrium-doped barium cerate : a concurrent structural and dynamic study, J. Phys. Chem. C, 111 (2007) 6574-6580.