Structural stability in advanced materials is one of the most intriguing challenges in modern soft matter physics. As complex fluid and nematic systems find broader applications in material science, traditional observation techniques struggle to capture their dynamic orientation and defect behavior with sufficient accuracy and detail.
In this seminar, Prof. Pawel Pieranski (Laboratoire de Physique des Solides, Université Paris-Saclay, France) will explore the frontier of shear flow effects in nematic liquid crystals and their fundamental hydrodynamic coupling. He will highlight how velocity gradients dictate molecular orientation and give rise to surprising instability patterns, demonstrating recent insights into the behavior of disclinations and helical texture inversions under dynamic shear.
Key Topics Covered:
- Hydrodynamics of Nematics: Understanding the fundamental coupling between velocity fields $v(x,y,z,t)$ and director fields $n(x,y,z,t)$.
- Shear Flow Instabilities: Exploring the emergence of instability patterns and disclination loops in homogeneous textures under orthogonal shear flow.
- Twisted Textures & Disclination Dynamics: Investigating how alternating shear flows set disclinations into motion within right-hand twisted structures.
- Helical Inversion: Demonstrating how strong shear flow impulses can continuously invert right-handed helices into left-handed helix configurations.
The lecture will ultimately address a fundamental question: how can velocity gradients and shear dynamics transform our understanding and control of molecular order in complex nematic materials?
Event Details:
- Date: 16 November 2026 | Time: 11:30
- Location: CENIMAT|i3N Amphitheater
- Speaker: Prof. Pawel Pieranski (Université Paris-Saclay, France)