Slow single-molecule diffusion in liquid crystals.
We report on measurements of single-molecule Brownian motion in liquid crystals, unravelling the anisotropic mobility of individual dye molecules. This anisotropic Brownian motion is directly correlated with the structural properties in a smectic A (8CB) and a nematic (5CB) liquid crystal sample cell on the micrometer scale using polarization contrast microscopy. A considerably slower mobility of dye molecules is found as compared to self-diffusion measurements by NMR, while anisotropy values compare well to recent literature data. This is suggested to be related to local distortions of the director structure around the dye molecules.
Molecular Nanophotonics, Institute of Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany.
Martin
M
Pumpa
Frank
F
Cichos
D004396:Coloring Agents / Q000737:chemistry*; D004058:Diffusion; D050866:Liquid Crystals / Q000737:chemistry*; D015394:Molecular Structure
D004396:Coloring Agents