title: Alignment of Red Poly[dodecadyin-1,12-diol-bis(4-butoxycarbonyl-methyl-urethane)] in Couette Flow.
abstract: The flow-induced alignment of red poly[dodecadyin-1,12-diol-bis(4-butoxycarbonyl-methyl-urethane)] (poly-4BCMU) in chloroform/toluene solution is reported. Absorption spectra have been measured over a range of shear rates in an optically transparent quartz Couette cell. The measured spectra show that the poly-4BCMU structure stays the same in flow, while the measured absorbance anisotropy is attributed to the flow-induced particle alignment in the red form poly-4BCMU solutions. A limiting orientation at shear rates >50 s(-1) is observed. Numerical simulations show that the spectral changes are consistent with the rodlike poly-4BCMU particle having an aspect ratio of 2.9. The dichroic ratio of 1.9 interpreted from the data indicates that the individual poly-4BCMU chains do not aggregate amorphously in the rodlike conformation, rather they show a preferred orientation along the long axis of the prolate aggregates.
authors: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors: Donglin
authors: D
authors: Xie
authors: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors: Yalin
authors: Y
authors: Wei
authors: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors: Greg G
authors: GG
authors: Qiao
authors: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors: Dave E
authors: DE
authors: Dunstan