Structure and anisotropic dynamics of stimuli responsive colloidal ellipsoids at the nearest neighbor length scale

J Colloid Interface Sci. 2022 Sep:621:352-359. doi: 10.1016/j.jcis.2022.04.063. Epub 2022 Apr 15.

Abstract

Stimuli-responsive self-assembly of (an) isotropic colloids has resulted in a plethora of self-assembled structures with potential applications in fabricating smart materials. A lack of detailed understanding of the interplay between these self-assembled structures and the resulting dynamics has often impeded the exploitation of their full potential. Herein, we have unveiled the relationship between the field-driven self-assembled structures and the corresponding collective dynamics at the nearest neighbor length scale using X-ray photon correlation spectroscopy and magnetic colloidal ellipsoids. We demonstrate that the effective long-time collective diffusion coefficient, Deff(q), scales with the inverse of the scattered intensity for various stimuli-responsive self-assembled phases. At high-volume fraction, the system approaches a kinetically arrested state. The anisotropic slowdown of Deff(q) hints towards the formation of an oriented glass. Our approach opens new avenues for exploring the stimuli-responsive dynamics of strongly interacting colloidal systems with diverse shapes and properties.

Keywords: Anisotropic dynamics; Liquid crystals; Magnetic anisotropic colloids; SASX; Self-assembly; XPCS.

MeSH terms

  • Colloids* / chemistry
  • Magnetics*

Substances

  • Colloids