Polymer and Colloid Science Group People Research Activities Collaborations Output Funding Selected Presentations IESL:03/ 2006

MS-Students:N. Gomopoulos, N. Koumakis, P. Voudouris Five diploma work Students PEOPLE (current state) B. Loppinet, G. Petekidis (Researcher’s) G. Fytas, D. Vlassopoulos (Dept. Mat. Sci. Faculty Members) A. Larsen : Physics Technician Post Docs:E. van Ruymbeke, PhD Students: M. Gianneli, M. Kapnistos, V. Michailidou, M. Stiakakis, Cheng Wei, Visiting Scientists: T. Caremans (Leuven), E. Filippidi (Harvard), J. Gapinski (Poznan), A. Kröger (Mainz), K. Pham (Edinburgh), S. Roberts (N. Zealand), E. Sanders (Eindhoven), T.Sanders (Eindhoven), J. Stellbrink (Jülich)

Research Activities Problems: –Soft Colloids: effective interactions, dynamics and rheology –Dynamics and non-linear rheology of colloidal glasses and gels –Dynamics of surface tethered polymers –Macromolecular architecture, self assembly and relaxation in polymeric systems –Laser induced concentration gradients in transparent polymer solutions –Phonons in soft structures Development of Experimental Tools  EWDLS and combination with SPR  Combination of DLS-Echo and Rheology  FCS in Polymer Science  BS of soft structures

Collaborations Examples of Over the Globe 1.P. N. Pusey, Edinburgh (Faraday Disc. 2004) 2.C. Likos, Düsseldorf (PRL 2003) 3.J. Rühe, IMTEK Freiburg (PRL 2004) 4.E. L. Thomas, MIT (PRL 2005) 5.MPIP (Mainz) 1.E. N. Economou, IESL (PRL 2003) 2.N. Vainos, EIE (Science 2002, JACS 2005) 3.N. Hadjichristidis (Macromolecules…) 4.ICEHT Patras: S. Yannopoulos, B. Marranzas 5.Demokritos: T. Vourlinos D. N. Theodorou international national collaborations

Selected Presentations 1. Polymers Responsive Brushes Control Processing (through macromolecular architecture) 2. Colloids Vitrification and flow of colloidal glasses and gels Hypersonic phononic crystals

Light scattering in the evanescent geometry PS brushes in good solvent Polymer Brush Dynamics G. F., Science 1996

Responsive Brushes Bad Good PS brushes in marginal solvent (cyclohexane) G. Yakubov, PRL 2004 V.Michailidou Macromolecules 2005

Rheology of Branched Polymers Seniority Rules: Outer branches relax first. Separated in time relaxation processes. Mean Field tube model.

Vitrification and flow of colloidal glasses and gels Effects of Interparticle Interactions From Hard Spheres to Repulsive (soft) and Attractive Systems Hard spheres Attractive spheres (Depletion attraction: Hard sphere-polymer mixtures) Soft Spheres Multiarm stars

Light Scattering Echo + Rheology Dynamic Light scattering under oscillatory shear t=0 t=T/2 t=T Peaks in g (2) (t) (echoes) => elastic (reversible) response of the sample G. Petekidis et al. Faraday Discuss. (2003)

self-assembling and infiltration procedures J.Wang,U.Jonas

Inelastic Brillouin Light Scattering H.Kriegs(2003)

Bragg gap

Scattering Geometry

1.Dry Opals particle vibrations (elastic constants) W. Cheng J.C.P (2005), M.Faatz Langmuir(2005) Music of Spheres

Perspectives (research character) Molecular Objects Design Desired Function Advanced Fields eg. Polymers Colloids Antagonistic Forces, Selection Appropriate Morphology, Recognition Phononic Devices, Sensors, Motors

Future directions/needs Bio-functional surface architecture (external collaboration: J. Rühe, J. Knoll) Understanding of self-assembly and functions of bio-related systems (collaborations: K. Tokatlidis, A. Mitraki, University of Crete) Single Macromolecule probing and manipulation Needs: Soft Matter theory/simulation Experimentalist in biorelated systems