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Updated: Oct 26, 2025
10:56
Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
12.3K
Colloidal aggregation in anisotropic liquid crystal solvent.
Devika Gireesan Sudha1, Jocelyn Ochoa, Linda S Hirst
1Department of Physics, University of California, Merced, 5200 N. Lake Rd, Merced, CA 95343, USA. lhirst@ucmerced.edu.
Soft Matter
|July 29, 2021
Summary
Colloidal particles in liquid crystals form unique fractal structures and gels. A new self-assembling system allows researchers to study this aggregation process and its driving mechanisms.
Area of Science:
- Soft Matter Physics
- Materials Science
- Colloid Science
Background:
- Colloidal particle aggregation in anisotropic fluids like liquid crystals forms distinct hierarchical structures compared to isotropic fluids.
- Studying this aggregation was previously limited by challenges in achieving well-dispersed colloid distributions and optimal imaging conditions.
Purpose of the Study:
- To investigate colloidal particle aggregation in nematic liquid crystals using a novel self-assembling system.
- To explore the formation of fractal structures and colloidal gels and the factors influencing their morphology.
Main Methods:
- In situ formation of hollow, micron-scale colloids within the nematic phase.
- Utilizing fluorescence microscopy to analyze aggregate structures across various length scales.
- Systematically varying colloid concentration and temperature quench depth to observe aggregation dynamics.
Main Results:
- Hierarchical aggregate morphologies, including fractal structures and colloidal gels, were successfully formed.
- Aggregate structures were found to be dependent on colloid concentration and the depth of the temperature quench across the isotropic-nematic phase transition.
- Ageing mechanisms and driving forces for aggregation were observed and analyzed.
Conclusions:
- The self-assembling colloidal system offers a powerful new method for studying particle aggregation in liquid crystals over large length scales.
- Aggregate dynamics are influenced by a combination of Frank elasticity relaxation, spontaneous defect line annihilation, and internal aggregate fracturing.
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