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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 15: Theory and Simulation (joint session CPP/DY)

CPP 15.3: Vortrag

Freitag, 1. Oktober 2021, 14:15–14:30, H3

Surface Segregation in Athermal Polymer Blends due to Conformational Asymmetry — •Russell Spencer¹ and Mark Matsen² — ¹Georg-August Universität Göttingen, Institute for Theoretical Physics, 37077 Göttingen, Germany — ²University of Waterloo, Waterloo, Ontario, Canada

Monte Carlo simulations are used to investigate the surfaces of athermal blends of stiff and flexible polymers. We vary the bending modulus of the stiff polymers, κ, from zero to the point where the bulk undergoes an isotropic-to-nematic transition. For hard walls characteristic of polymer/solid surfaces, the flexible polymers generally segregate to the surface. However, prior to the bulk transition, there is a surface ordering transition, where a thin nematic layer rich in stiff polymers forms at the surface. On increasing κ further, the thickness of the nematic layer rapidly increases as the bulk isotropic-to-nematic transition is approached. For soft boundaries representative of polymer/air surfaces, a thin layer rich in stiff polymers but without nematic order forms on the outer edge of the surface with a more significant layer rich in the flexible chains beneath. In this case, the nematic layer never appears, and the surface profile evolves continuously with increasing κ.