Tailoring the flow of soft glasses by soft additives

TL;DR

This paper investigates how adding small star polymers affects the vitrification and melting of asymmetric star polymer mixtures, revealing two distinct glassy states and a non-monotonic melting behavior influenced by size ratios.

Contribution

It introduces a combined rheological and theoretical analysis of asymmetric star polymer mixtures, identifying novel glassy states and their melting dynamics.

Findings

Identification of single and double glassy states

Melting curves show non-monotonic dependence on size ratio

External control of rheological behavior in soft matter systems

Abstract

We examine the vitrification and melting of asymmetric star polymers mixtures by combining rheological measurements with mode coupling theory. We identify two types of glassy states, a {\it single} glass, in which the small component is fluid in the glassy matrix of the big one and a {\it double} glass, in which both components are vitrified. Addition of small star polymers leads to melting of {\it both} glasses and the melting curve has a non-monotonic dependence on the star-star size ratio. The phenomenon opens new ways for externally steering the rheological behavior of soft matter systems.