Regensburg 2019 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster Session I

CPP 17.39: Poster

Montag, 1. April 2019, 17:30–19:30, Poster B1

Thermal Oscillations in Homopolymer Blends — •Louis Pigard and Marcus Müller — Institute for Theoretical Physics, University of Göttingen, Germany

Immiscible homopolymer blends are binary mixtures that exhibit macroscopic phase-separation of their constituents A and B in equilibrium. The immiscibility of A and B is commonly characterized by the interaction parameter χN. For sufficiently high χN the blend demixes into two macroscopic A- and B-rich domains that are spatially separated by a single interface.

We study how this behaviour is altered if the temperature of the system and thus χN is oscillating in time. We model the dynamics by the Cahn-Hilliard equation and, additionally, verify our results with Monte-Carlo simulation of a soft, coarse-grained particle model that mimics Rouse dynamics.

For suitable values for the amplitude and period of the oscillation we observe the emergence of new metastable states with three interfaces and four domains in a thin-film geometry, i.e., the oscillation of incompatibility qualitatively changes the behavior from macro- to microphase separation in a thin film geometry.

We study the dependence of this microphase-separated state on the strength and frequency of the oscillation and explore the (meta)stability of the new, oscillation-induced state.