Wissenschaftliche Arbeit

Flüssigkristalle

Flüssigkristalle sind anisotrope Flüssigkeiten, die im Unterschied zu gewöhnlichen Flüssigkeiten zumindest eine Orientierungsfernordnung besitzen. Sie bestehen meist aus stäbchenförmigen Teilchen und können sowohl als niedermolekulare als auch als polymere Materialien vorliegen. Die Ketten in flüssigkristalline Polymeren können auch vernetzt werden. Daraus resultieren flüssigkristalline Elastomere, Materialien mit anisotropen gummielastischen Eigenschaften.

Arbeitsgebiete

• Optische Eigenschaften von Flüssigkristallen mit Helixstruktur
• Transiente und stationäre dissipative Strukturen in flüssigkristallinen Systemen
• Mikroskopische und makroskopische Rotationsbewegung in nematischen Flüssigkristallen
• Einfluß der Hauptkette auf die Rotationsdynamik in polymeren Flüssigkristallen
• Dynamisch-mechanische und -spannungsoptische Eigenschaften flüssigkristalliner Elastomerer
• Kritische Phänomene bei Phasenübergängen von Flüssigkristallen

Veröffentlichungen

• Kaiwan Jahanshahi, Ioan Botiz, Renate Reiter, Ralf Thomann, Barbara Heck, Roozbeh Shokri, Werner Stille, Günter Reiter,
  Crystallization of Poly(γ-benzyl L-glutamate) in Thin Film Solutions: Structure and Pattern Formation,
  Macromolecules 46, 1470-1476 (2013). Abstract
• Felicitas Brömmel, Werner Stille, Heino Finkelmann, Anke Hoffmann,
  Molecular dynamics and biaxiality of nematic polymers and elastomers,
  Soft Matter 7, 2387-2401 (2011). Abstract
• Ralf Delto, Werner Stille, Gert Strobl,
  Depression of the Zero Growth Temperature by Counits Observed for s-Polypropylene in Light Attenuation Experiments,
  Macromolecules 43, 1035-1040 (2010). Abstract
• W. Stille,
  Metastable Untwisted States in Cholesteric Elastomers,
  Macromolecules 42, 7979-7981 (2009). Abstract
• W. Stille,
  Deformation of cholesteric elastomers by uniaxial stress along the helix axis,
  Eur. Phys. J. E 28, 57-71 (2009). Abstract
• T.-Y. Cho, W. Stille, G. Strobl,
  Zero growth temperature and growth kinetics of crystallizing poly(ε-caprolactone),
  Colloid Polym. Sci. 285, 931 (2007). Abstract
• T.-Y. Cho, W. Stille, G. Strobl,
  Zero Growth Temperature of Crystallizing Polyethylene,
  Macromolecules 40, 2596 (2007).
• W. Stille, J. Schmidtke,
  The role of Frank elasticity in cholesteric elastomers,
  Eur. Phys. J. E 22, 117 (2007). Abstract
• C. Bourgerette, B. Chen, H. Finkelmann, M. Mitov, J. Schmidtke, W. Stille,
  Variation of the Network Anisotropy of Cholesteric Side Chain Elastomers,
  Macromolecules 39, 8163 (2006). Abstract
• J. Fritsch, W. Stille, G. Strobl,
  Investigation of polymer crystallization kinetics with time dependent light attenuation measurements,
  Colloid Polym. Sci. 284, 620 (2006). Abstract
• J. Schmidtke, W. Stille,
  Photonic defect modes in cholesteric liquid crystal films,
  Eur. Phys. J. E 12, 553 (2003). Abstract
• J. Schmidtke, W. Stille, H. Finkelmann,
  Defect Mode Emission of a Dye Doped Cholesteric Polymer Network,
  Phys. Rev. Lett. 90, 083902 (2003). Abstract
• J. Schmidtke, W. Stille,
  Fluorescence of a dye-doped cholesteric liquid crystal film in the region of the stop band: theory and experiment,
  Eur. Phys. J. B 31, 179 (2003). Abstract
• J. Schmidtke, W. Stille, H. Finkelmann, S. T. Kim,
  Laser Emission in a Dye Doped Cholesteric Polymer Network,
  Adv. Mater. 14, 746 (2002).
• M. Schönstein, W. Stille, G. Strobl,
  Effect of the Network on the Director Fluctuations in a Nematic Side-Group Elastomer Analysed by Static and Dynamic Light Scattering,
  Eur. Phys. J. E 5, 511 (2001). Abstract
• F. Schmidt, J. Siepmann, W. Stille, G. R. Strobl,
  Dynamics of Backbone Chain and Side Groups in a Nematic Liquid Single Crystal Elastomer Studied by Combined Mechanical and Stress-optical Measurements,
  Mol. Cryst. Liq. Cryst. 350, 103 (2000). Abstract
• J. Schmidtke, W. Stille, G. Strobl,
  Static and dynamic light scattering of a nematic side-group polysiloxane,
  Macromolecules 33, 2922 (2000). Abstract
• E. E. Pashkovsky, W. Stille, G. Strobl, D. Talebi,
  Director Field Patterns of Nematic Polymer Solutions at Asynchronous Rotation in a Rotating Magnetic Field,
  Mol. Cryst. Liq. Cryst. 302, 403 (1997). Abstract
• E. E. Pashkovsky, W. Stille, G. Strobl, D. Talebi,
  The Effect of Dissolved Side-Group Polymers on Pattern Formation in Nematic Liquid Crystals in a Rotating Magnetic Field,
  J. Phys. II France 7, 707 (1997). Abstract
• E. E. Pashkovsky, T. G. Litvina, W. Stille, G. Strobl,
  The Dynamics of Freedericksz Transitions in Nematic Solutions of Mesogenic Polymers,
  Vysokomolekulyarnye Soedineniya Seriya A 37, 1272 (1995). Abstract
• A. Raviol, W. Stille, G. Strobl,
  The effect of molecular association and tube dilation on the rotational viscosity and rotational diffusion in nematic liquid crystals,
  J. Chem. Phys. 103, 3788 (1995). Abstract
• E. E. Pashkovsky, W. Stille, G. Strobl,
  Periodic Pattern Formation in Side-Group Polymer Nematic Solutions at the Twist Frederiks Transition,
  J. Phys. II France 5, 397 (1995). Abstract
• W. Stille, G. Strobl,
  Dynamics of Rotational Motion in Liquid Crystalline Systems,
  in: R. Richert, A. Blumen (Eds.), Disorder Effects on Relaxational Processes, p. 725, Springer, Berlin (1994).
• R. Sigel, W. Stille, G. Strobl, R. Lehnert,
  Near-Critical Behavior of the Dynamic Stress-Optical Coefficient in Liquid Crystalline Elastomers,
  Macromolecules 26, 4226 (1993). Abstract
• G. Christoph, W. Stille, G. Strobl,
  Dependence of the rotational viscosity of nematic mixtures on the rotational diffusion constants of their components,
  J. Chem. Phys. 99, 3075 (1993). Abstract
• S. Götz, W. Stille, G. Strobl, H. Scheuermann,
  Molecular Weight Dependence of the Rotational Diffusion Constant and the Rotational Viscosity of Nematic Side-Group Polymers,
  Ber. Bunsenges. Phys. Chem. 97, 1315 (1993). Abstract
• W. Stille, G. R. Strobl,
  Kinetics of Rotational Motion in Liquid-Crystalline Polymers,
  Polym. Sci. (Russia) 35, 1484 (1993). Abstract
• S. Götz, W. Stille, G. Strobl, H. Scheuermann,
  Molecular Weight Dependence of the Rotational Diffusion Constant and the Rotational Viscosity of Nematic Side-Group Polymers,
  Macromolecules 26, 1520 (1993). Abstract
• R. Mutter, W. Stille, G. Strobl,
  Transition Regions and Surface Melting in Partially Crystalline Polyethylene: A Raman Spectroscopic Study,
  J. Polym. Sci. Part B: Polym. Phys. 31, 99 (1993). Abstract
• S. Immerschitt, W. Stille, G. Strobl,
  Use of Ellipsometry in a Study of the Surface Order in the Isotropic Phase of a Liquid Crystalline Polyacrylate,
  Macromolecules. 25, 3227 (1992). Abstract
• S. Immerschitt, T. Koch, W. Stille, G. Strobl,
  Pretransitional nematic surface order in the isotropic phase of phenylcyclohexanes,
  J. Chem. Phys. 96, 6249 (1992). Abstract
• H. Seiberle, W. Stille, G. Strobl,
  Comparative Study of Individual and Collective Rotational Motion in Mixtures of Liquid Crystalline Side Group Polymers and Low Molecular Weight Mesogens,
  Macromolecules 23, 2008 (1990). Abstract
• H. Stegemeyer, W. Stille, P. Pollmann,
  Circular Fluorescence Polarization of Achiral Molecules in Cholesteric Liquid Crystals,
  Israel J. Chem. 18, 312 (1979). Abstract