Kinetics of the orientation transition in the lyotropic lamellar phase

Abstract

Kinetics of the orientation transition in the triblock copolymer lamellar phase is studied by viscometry. We find that the strain-controlled mechanism dominates the transition kinetics. We propose a possible scenario of the orientation transition from the viewpoint of the dislocation dynamics. We could also evaluate the critical shear rate of the orientation transition by assuming the limiting velocity of the dislocations under shear. evaluated value is in good agreement with the experimental observation. the nucleation of the dislocations might be necessary for the orientation transition.

Shear-Induced Ordering of Nanopores and Instabilities in Concentrated Surfactant Mesh Phases

“…In order to draw a functional relationship between the timescale of NEPT and the shear rate, one has to check whether the transition is a strain-controlled or shear rate-controlled process. If it is a strain-controlled process, one expects inverse relationship between the timescale and the shear rate . Otherwise, for the shear rate/stress-controlled process, a power-law dependence of the timescale with the applied shear rate/stress is expected.…”