Relaxation dynamics in multicomponent glass formers with adjustable concentration fluctuations

Abstract

Here, we study the structural relaxation kinetics in modified binary (i.e., ternary) mixtures with strong concentration fluctuation imposed by a polar picoline and an apolar triphenylethylene by adding a surfactant phenanthridine. The dielectric and enthalpy relaxation measurements are applied to monitor the dynamic properties aiming at distinguishing various effects of the concentration fluctuation. It is found that the strong concentration fluctuations are largely suppressed by adding the surfactant molecule. However, compared with the binary mixtures, a larger difference in the glass transition temperatures determined by the dielectric and enthalpy methods is observed in some of the ternary mixtures. Another unusual behavior in the ternary mixtures is that the enthalpy relaxation produces higher non-exponential factor β than the dielectric relaxation. The comparison of various parameters confirm that the reduced glass transition width is more suitable for characterizing the strength of concentration fluctuations in multi-component systems.