Coupling and decoupling between translational and rotational dynamics in supercooled monodisperse soft Janus...

Area of Science:

• Soft Matter Physics
• Computational Chemistry
• Materials Science

Background:

• Understanding glassy dynamics is crucial for designing novel materials.
• Janus particles, with their distinct surface properties, offer unique self-assembly and dynamic behaviors.
• Anisotropic interactions in soft matter systems significantly impact particle motion.

Purpose of the Study:

• To investigate the translational and rotational glassy dynamics of soft Janus particles.
• To elucidate the role of interaction anisotropy in the dynamics of glass-forming liquids.
• To differentiate the contributions of translational and rotational motion to the glass transition.

Main Methods:

• Performing molecular dynamics simulations.
• Analyzing mean-square displacement (translational and reorientational).
• Quantifying coupling between translational and rotational relaxations and diffusions.

Main Results:

• Rotational dynamics lack clear plateau behavior in the caging region, unlike translational motion.
• Coupling between translational and rotational relaxation increases upon cooling.
• Strong decoupling of translational and rotational diffusion arises from suppressed translation and promoted rotation.

Conclusions:

• Interaction anisotropy critically governs the translational and rotational dynamics of soft Janus particles.
• Hopping motion and collective cage motion explain the observed decoupling at low and high temperatures, respectively.
• Reorientational mean-square displacement is essential for recognizing rotational caging behavior.