Authors Shagolsem, L. ; Kreer, T. ; Galuschko, A. ; Sommer, J.-U.
Title Diblock-copolymer thin films under shear
Date 01.10.2016
Number 51121
Abstract The behavior of lamellae forming diblock-copolymer melts confined by two non-selective substrates under shear is studied by means of molecular dynamics simulations. Since the substrate/copolymer preferential interaction is absent, the vertically oriented lamellae (L·) are formed. The response of L· phase under transverse and perpendicular modes of shear is studied for a wide range of shear rates, ·· . In particular, shear deformation and reorientation transition, flow behavior, and difference in the macroscopic response under the two modes of shear are discussed. We show that an inclined lamellae state observed for transverse shear below a critical shear rate ·· * is stabilized by a cyclic motion of chains close to the substrates. The value of ·· *, at which lamellae dissolve and reorient along the flow field during transverse shear, coincides with the onset of shear-thinning. For ·· <·· *, the shear viscosity for transverse shear is much larger compared to that observed in perpendicular shear, while there is no difference for ·· >·· *.
Publisher Journal of Chemical Physics
Wikidata 2
Citation Journal of Chemical Physics 145 (2016) ID164908

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