A study of molecular dynamics within liquid flows using fluorescence depolarization

Molecular alignment within thin laminar jets of rhodamine 6G in solution in ethylene glycol has been investigated by measuring the depolarization of laser induced fluorescence. From measurements of a large number of points within the flow, we have built up maps of molecular alignment which display in detail the distribution and evolution of flow alignment. On the basis of these observations, we analyse the evolution of molecular alignment in terms of internal shear forces resulting from velocity distributions within liquid flows.