Effect of steady shear on multi-axial texture of symmetric diblock copolymers

Abstract

The effect of steady shear on multi-axial texture of symmetric diblock copolymer was investigated by using dynamic density functional theory. Through modifying the periodic boundary condition, the parallel-transverse biaxial texture and perpendicular-parallel-transverse triaxial texture have been observed. In the formation of the multi-axial texture, there are two critical velocities u per par -* and u par tra -* , at which the transition between the perpendicular and the parallel lamellar morphology, and the transition between the parallel and the transverse lamellar morphology occur, respectively. The two critical velocities increase as the interaction parameter increases, but they almost remain constant at different shear rates. Furthermore, the rotation from the transverse lamellae to the parallel lamellae induced by the shear strain, and the increase of lamellar spacings of the three lamellae after removing the shear, have also been observed by the time evolution of the morphologies. These phenomena are consistent with experimental work.

Classical dynamical density functional theory: from fundamentals to applications

“…Scacchi et al [447] studied the influence of shear on length scales in soft matter. Polymer DDFT (see Section 3.2.3) is also frequently applied to sheared systems [51,[433][434][435][436][437][438][439][440][441][442][443][444][445][446]. Hoell et al [411] model a shear cell consisting of microswimmers trapped in passive colloidal particles.…”

“…They were among the first systems studied using DDFT and the theory presented in Section 3.2.3 is now one of the most widely used methods in the simulation of polymer systems. Applications include phase behavior [55,[360][361][362]433,524,, systems under shear [51,[433][434][435][436][437][438][439][440][441][442][443][444][445], pattern formation and self-organization [56,269,270,[866][867][868][869][870][871][872][873][874][875][876][877][878][879][880][881], effects of electric fields [882][883][884][885], adsorption/desorption kinetics [886], thin films [55,56,…”