STRONG MOLECULAR ALIGNMENT IN ANISOTROPIC FLUID MEDIA

Picosecond polarised fluorescence studies of rhodamine 6G molecules in a 100 mu m free ethylene glycol jet show the production of strong mol ecular alignment with a degree of ordering between one to two orders o f magnitude greater than that attainable for similar systems using con ventional fluid alignment techniques. Using a novel variation of the p olarised picosecond single-photon counting technique, it has been poss ible to prepare a range of non-equilibrium molecular orientational dis tributions in the jet and observe their subsequent evolution. The impo sition of order in the flow is seen to have a distinct effect on molec ular motion, indicating a strong anisotropy in theta and phi rotationa l diffusion dynamics.