POISEUILLE GEOMETRY SHEAR-FLOW APPARATUS FOR SMALL-ANGLE SCATTERING EXPERIMENTS

A new apparatus to investigate the structure of fluids under Poiseuill e shear flow using small-angle neutron or light scattering techniques is described. Important features of the design include low sample volu mes, area average shear rates of up to 5000 s(-1), accurate temperatur e control over the range of 10-125 degrees C, and the ability to study the development of flow-induced alignment phenomena. Small-angle neut ron scattering data are presented for two example systems: the well-ch aracterized surfactant system C(16)E(6)/D2O, used to contrast the effe cts of Poiseuille and Couette flow, and the block copolymer Synperonic P-85/D2O system. (C) 1996 American Institute of Physics.