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Molecular self-organization in cylindrical nanocavities.
S G Cloutier1, J N Eakin, R S Guico
1Division of Engineering and Department of Physics, Brown University, Providence, Rhode Island 02912, USA. Sylvain_Cloutier@brown.edu
Summary
We investigated molecular ordering in nanocavities using liquid crystals. High surface ordering was observed above bulk critical temperatures, revealing unique phase behaviors and continuous transitions due to nanoconfinement.
Area of Science:
- Materials Science
- Physical Chemistry
- Nanoscience
Background:
- Understanding molecular organization within nanoconfined environments is crucial for developing advanced materials.
- Liquid crystals exhibit unique phase behaviors sensitive to surface interactions and confinement.
Purpose of the Study:
- To investigate the molecular organization and phase transitions of liquid crystals within cylindrical nanocavities.
- To analyze the impact of surface potential and nanoconfinement on liquid crystal ordering.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy was employed to probe molecular ordering.
- Studies were conducted on liquid crystals confined within cylindrical nanocavities.
Main Results:
- High surface-induced ordering was observed significantly above the bulk critical temperature.
- The isotropic phase was replaced by a paranematic phase, and surface-induced disordering occurred in the nematic phase.
- Complete wetting and continuous evolution of the surface-order parameter were observed across the nematic-paranematic transition.
Conclusions:
- The study demonstrates counter-intuitive interfacial behavior, with no complete phase transition at the interface despite an abrupt bulk transition.
- Observed phenomena align with established theories on surface potential and nanoconfinement effects in liquid crystals.