Shape and structural relaxation of colloidal tactoids.

Area of Science:

• Colloid and Interface Science
• Soft Matter Physics
• Materials Science

Background:

• Liquid crystalline colloids exhibit responsive geometric-structural properties crucial for technological applications.
• The dynamic relaxation mechanisms of these colloids, particularly under mobile boundaries, remain largely unexplored.
• Understanding tactoid relaxation is key to developing advanced responsive materials.

Purpose of the Study:

• To investigate the shape and structural relaxation dynamics of colloidal liquid crystalline micro-droplets (tactoids) under mobile boundaries.
• To develop a predictive model for the out-of-equilibrium relaxation process.
• To elucidate the influence of internal liquid crystalline structures on relaxation pathways.

Main Methods:

• Combined experimental observations with numerical simulations and theoretical analysis.
• Utilized amyloid fibrils and cellulose nanocrystals as model systems for liquid crystalline colloids.
• Analyzed the decay signatures of tactoid shape and internal structure relaxation.

Main Results:

• Tactoid shape relaxation follows a universal single exponential decay signature.
• Derived an analytic expression predicting this relaxation, governed by anisotropic and isotropic liquid crystalline contributions.
• Tactoid structural relaxation pathways differ fundamentally, exhibiting first- and second-order exponential decays based on ground state orientation structures (splay/bend/twist).

Conclusions:

• This study provides a comprehensive understanding of dynamic confinement effects in liquid crystalline colloidal systems.
• The findings offer a predictive framework for tactoid relaxation dynamics.
• The research opens new avenues for designing novel responsive materials based on liquid crystalline colloids.