Binary colloidal glasses: linear viscoelasticity and its link to the microscopic structure and dynamics

Soft Matter ◽  
2019 ◽  
Vol 15 (10) ◽  
pp. 2232-2244 ◽  
Author(s):  
Tatjana Sentjabrskaja ◽  
Alan R. Jacob ◽  
Stefan U. Egelhaaf ◽  
George Petekidis ◽  
Thomas Voigtmann ◽  
...  
Keyword(s):  
Linear Viscoelasticity ◽  
Microscopic Structure ◽  
Particle Species ◽  
Structure And Dynamics ◽  
Colloidal Glasses

We determine the contributions of each particle species to the macroscopic rheology of highly asymmetric binary colloidal mixtures.

scholarly journals Disconnecting structure and dynamics in glassy thin films

2017 ◽  
Vol 114 (40) ◽  
pp. 10601-10605 ◽  
Author(s):  
Daniel M. Sussman ◽  
Samuel S. Schoenholz ◽  
Ekin D. Cubuk ◽  
Andrea J. Liu
Keyword(s):  
Thin Film ◽  
Machine Learning ◽  
Thin Films ◽  
Predictive Models ◽  
Local Structure ◽  
The Other ◽  
Microscopic Structure ◽  
Glassy Dynamics ◽  
Structure And Dynamics ◽  
Machine Learning Methods

Nanometrically thin glassy films depart strikingly from the behavior of their bulk counterparts. We investigate whether the dynamical differences between a bulk and thin film polymeric glass former can be understood by differences in local microscopic structure. Machine learning methods have shown that local structure can serve as the foundation for successful, predictive models of particle rearrangement dynamics in bulk systems. By contrast, in thin glassy films, we find that particles at the center of the film and those near the surface are structurally indistinguishable despite exhibiting very different dynamics. Next, we show that structure-independent processes, already present in bulk systems and demonstrably different from simple facilitated dynamics, are crucial for understanding glassy dynamics in thin films. Our analysis suggests a picture of glassy dynamics in which two dynamical processes coexist, with relative strengths that depend on the distance from an interface. One of these processes depends on local structure and is unchanged throughout most of the film, while the other is purely Arrhenius, does not depend on local structure, and is strongly enhanced near the free surface of a film.

scholarly journals Brillouin Light Scattering Study of Microscopic Structure and Dynamics in Pyrrolidinium Based Ionic Liquids

2020 ◽  
Author(s):  
Supti Das ◽  
Dhanya Radhakrishnan ◽  
Venkata. S. Bhadram ◽  
Chandrabhas Narayana ◽  
Aninda J. Bhattacharyya
Keyword(s):  
Ionic Liquids ◽  
Phase Transitions ◽  
Light Scattering ◽  
Solid Phase ◽  
Microscopic Structure ◽  
Temperature Dependent ◽  
Brillouin Light Scattering ◽  
Acoustic Modes ◽  
Structure And Dynamics ◽  
Acoustic Velocities

<p>Pyrrolidinium based ionic liquids are known to be good ionic conductors even in solid-state around room temperature, which is attributed to the highly disordered plastic crystalline phase. Moreover, these ionic liquids are characterized by multiple phase transitions which include plastic, structural glass, and glassy crystal phases with varying levels of molecular disorder. Temperature-dependent Brillouin light scattering is used to investigate the phase transitions in a series of alkylmethylpyrrolidinium Bis(trifluoromethanesulfonyl) imides (P<i><sub>1n</sub></i>TFSI, n=1,2,4). Brillouin spectral features such as the number of acoustic modes, their shape, and linewidth provide the picture of different disordered phases resultant of dynamics at the microscopic scale. The longitudinal and transverse acoustic velocities in different phases are determined from the corresponding acoustic mode frequencies (Brillouin shift). Extremely low acoustic velocities in the solid phase of P<i><sub>11</sub></i>TFSI and P<i><sub>12</sub></i>TFSI are a consequence of a high degree of disorder and plasticity present in the system. Anomalous temperature-dependent behavior of linewidth and asymmetric (Fano) line shape of acoustic modes observed in certain phases of P<i><sub>1n</sub></i>TFSI could be due to the strong coupling between the Brillouin central peak and the acoustic phonons. The present results establish that the Brillouin light scattering technique can be efficiently used to understand the complex phase behavior, microscopic structure, and dynamics of ionic liquids.</p>

scholarly journals Microscopic structure and dynamics of molten Se50Te50 alloys

2007 ◽  
Vol 127 (14) ◽  
pp. 144707 ◽  
Author(s):  
N. A. Katcho ◽  
P. Zetterström ◽  
E. Lomba ◽  
L. C. Otero-Díaz ◽  
Y. D. Wang ◽  
...  
Keyword(s):  
Microscopic Structure ◽  
Structure And Dynamics

Microscopic Structure and Dynamics of LiBF4Solutions in Cyclic and Linear Carbonates

2011 ◽  
Vol 115 (49) ◽  
pp. 14563-14571 ◽  
Author(s):  
O. O. Postupna ◽  
Y. V. Kolesnik ◽  
O. N. Kalugin ◽  
O. V. Prezhdo
Keyword(s):  
Microscopic Structure ◽  
Structure And Dynamics
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