Paul Sotta

 

Laboratoire de physique des solides

Université Paris-Sud

Bât. 510

91405 Orsay Cedex

France

Tél. 

: +33 (0)1 69 15 53 05

Fax

: +33 (0)1 69 15 60 86

mailto:sotta@lps.u-psud.fr

 

 

 

CV   –   research   -   Publications   -   teaching

 

 

Short autobiography

 

1992          Chargé de recherche de première classe, CNRS

1995-1996   CNRS/MPG Gäst-Wissenschaftler, Max-Planck-Institut für Polymerforschung, Mainz

1988          Chargé de recherche de deuxième classe, CNRS

1987   Thèse de physique de l’Université Paris-Sud  (dir : B. Deloche)

Etude par résonance magnétique nucléaire du deutérium, de l’ordre orientationnel local dans un réseau polymère sous contrainte uniaxiale

1984    Ingénieur de l’Ecole Polytechnique

2005    Habilitation à diriger des Recherches  pdf

 

Research interests

 

My current main research interests focus on the dynamics of polymers above and close to the glass transition temperature, in the bulk, in thin films and at interfaces, as well as the behaviour of filled elastomers. I combine both experimental work (NMR, Small angle neutron and Xray scattering, thermomechanical analysis) and numerical simulations.

During and after my PhD thesis, I have studied the local order in elastomers by Nuclear Magnetic Resonance, mainly deuterium NMR. I demonstrated that the permanent orientational ordering of polymer segments induced upon macroscopic stretching may be used advantageously to characterize and study local ordering and/or chain stretching, i.e. the elastic energy stored in the polymer matrix.

I also worked on various aspects of the physics of liquid crystals: the relationship between structure and molecular dynamics, directional growth, phase transitions, faceting of cubic phases. I was the first author to observe and interpret 3D faceting in lyotropic cubic giant monocrystals.

I am currently working on reinforced elastomers, which are nanocomposites made of solid particles embedded in an elastomer matrix. I specifically aim at relating microscopic properties to macroscopic mechanical behavior. This includes:

- NMR measurements of the local constraints stored in the system as a function of the strain and of the fraction and aggregation state of solid reinforcing particles;

- NMR measurements of the polymer dynamics at or close to polymer/particle interfaces;

- characterization of the non linear and/or irreversible phenomena which occur in such systems, such as the Payne and Mullins effects and the plasticity (residual deformation  after large amplitude strain);

- characterization of the deformations induced by mechanical stretching at various spatial scales with Small Angle Neutrons and Xray scattering;

- dissipative molecular dynamics simulations of model disordered, reinforced elastic systems, to relate the macroscopic plasticity and long-time relaxation to the non-affine deformations at the scale of the reinforcing particles.

My projects are on the ultimate properties of nanostructured polymer systems, both in the experimental and numerical sides.

 

Selected publications

 

Ø       P. Sotta & B. Deloche, Uniaxiality induced in a strained Poly(dimethylsiloxane) network. Macromolecules, 23, 1999 (1990).

Ø       P. Sotta, Equilibrium shape of lyotropic cubic monocrystals. J. Phys. II France 1 (1991) 763.

Ø       P. Sotta & B. Deloche, Long-time dynamics in poly(dimethylsiloxane) networks studied by deuterium nuclear magnetic resonance. J. Chem. Phys. 100 (1994) 4591.

Ø       P. Sotta, Local orientational order in stretched poly(dimethlysiloxane) networks. in ‘Trends in Macromolecular Research’, ed. by The Council of Scientific Information, Trivandrum ,India (1994).

Ø       P. Sotta, P.G. Higgs, M. Depner & B. Deloche, Monte-Carlo Simulations of the Orientational Order in a Strained Polymer Network: Effect of Density. Macromolecules 28 (1995) 7208. pdf

Ø       P. Sotta, C. Fuelber, D.E. Demco, B. Bluemich & H.W. Spiess, Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-linked Elastomers. Macromolecules 29 (1996), 6222. pdf

Ø       L. Sallen, P. Sotta, P. Oswald, Pre-Transitional Effects near the Hexagonal-Micellar Phase Transition of the C12EO6/H2O Lyotropic Mixture. J. Phys. Chem. B 101 (1997) 4875.

Ø       A. Deluzet, H. Mayaffre, P. Wzietek, P. Sotta, E. Dumont & D. Jérome, Structural Transition in the Quasi-Two-Dimensional Organic Superconductor k-(ET)2Cu[N(CN)2]Br Studied by 13C MAS NMR. Advanced Materials 10 (1998) 797.

Ø       P. Sotta, Local order and induced orientation in PDMS model network, studied by 2H NMR. Macromolecules 31 (1998) 3872. pdf

Ø       P. Sotta, Local order and induced orientation in PDMS model network, studied by 2H NMR. Macromolecules 31 (1998) 8417. pdf

Ø       S. Valic, P. Sotta & B. Deloche, 2H-NMR study of a deformed PDMS rubber network below and above the crystallization temperature. Polymer 40 (1999) 989.

Ø       P. Sotta, S. Valic, B. Deloche, D. Maring, H. W. Spiess, Effect of the diamagnetic susceptibility in NMR measurements in diblock copolymers. Acta Polymerica 50 (1999) 205. pdf

Ø       O. Pelletier, P. Sotta, P. Davidson, Deuterium NMR Study of the Nematic Phase of Vanadium Pentoxide Aqueous Suspensions. J. Phys. Chem. 103 (1999) 5427. pdf

Ø       P. Pieranski, P. Sotta, D. Rohe, M. Imperor-Clerc, Devil's staircase-type facetting of a cubic lyotropic liquid crystal. Phys. Rev. Lett. 84 (2000) 2409. pdf

Ø       M. Imperor-Clerc, P. Sotta, M. Veber, Crystal shapes of cubic mesophases in pure and mixed carboxylic acids observed by optical microscopy. Liq. Cryst. 27 (2000) 1001.

Ø       P. Sotta, A. Lesne, J. M. Victor, Monte Carlo simulation of a grafted polymer chain confined in a pore. J. Chem. Phys. 112 (2000) 1565. pdf

Ø       P. Sotta, A. Lesne, J. M. Victor, The coil-globule transition for a polymer confined in a pore. J. Chem. Phys. 113 (2000) 6966. pdf

Ø       D. Constantin, P. Oswald, M. Imperor, P. Davidson, P. Sotta, Connectivity of the Hexagonal, Cubic and Isotropic Phases of the C12EO6/H2O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering. J. Phys. Chem. B. 105 (2001) 668. pdf

Ø       P. Pieranski, L. Sittler, P. Sotta, M. Imperor, Growth and shapes of a cubic lyotropic liquid crystal. EPJ E 5 (2001) 317. pdf

Ø       B. Deloche, P. Sotta, Deuterium NMR in Rubbery Materials. in 'Spectroscopy of Rubbers and Rubbery Materials', ed. by V.M. Litvinov and P.P. De, Rapra Technology ltd, UK (2002).

Ø       J. Berriot, F. Lequeux, L. Monnerie, H. Montès, D. Long, P. Sotta, Filler-Elastomer Interaction in Model Filled Rubbers, a 1H NMR Study. J. Non-Cryst. Solids 307 (2002) 719. pdf

Ø       J. Berriot, H. Montès, F. Lequeux, D. Long, P. Sotta, Evidence for the shift of the glass transition near the particles in model silica-filled elastomers. Macromolecules 35 (2002) 9756. pdf

Ø       J. Berriot, F. Martin, H. Montès, L. Monnerie, P. Sotta, Reinforcement of model filled elastomers: Characterization of the cross-link density at the filler-elastomer interface by 1H NMR measurements. Polymer 44 (2003) 1437. pdf

Ø       J. Berriot, H. Montès, F. Lequeux, D. Long, P. Sotta, L. Monnerie, A Mechanism for the Reinforcement of Filled Elastomers. Europhys. Lett. 64 (2003) 50. pdf

Ø       P. Sotta, D. Long, The crossover from 2D to 3D percolation. Theory and numerical simulations EPJ E 11 (2003) 375. pdf

Ø       S. Merabia, P. Sotta, D. Long, Heterogeneous nature of the dynamics and glass transition in thin polymer films, EPJ E 15 (2004) 189. pdf

Ø       D. Long, P. Sotta, Numerical Simulation for the mesoscale deformation of disordered reinforced elastomers, to appear, IMA Volume Series. pdf

 

 

Teaching activities

 

Though a CNRS member, I have been concerned by education and have given courses at the master level:

- the basics of polymer physics (material available here )

- fundamentals in liquid state and solid state Nuclear Magnetic Resonance (material available here )

 

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