Rotational diffusion of shape switching particles in nematic liquid crystals.

Area of Science:

• Physics, Soft Matter
• Physical Chemistry
• Materials Science

Background:

• Rotational diffusion theory for rigid particles in liquid crystals is established.
• Spectroscopic observables often rely on understanding particle dynamics.
• Previous models did not account for molecular flexibility or shape changes.

Purpose of the Study:

• To develop a generalized theory for rotational diffusion of shape-changing particles in nematic liquid crystals.
• To model the interplay between shape transitions and rotational dynamics.
• To provide a framework for interpreting experimental data involving flexible particles.

Main Methods:

• Developed a theoretical model incorporating an effective field potential for particle-environment interaction.
• Modeled shape transitions as a discrete Markovian process.
• Combined shape transition dynamics with rotational diffusion equations.
• Applied the model to a particle interconverting between rod, disk, and sphere shapes.

Main Results:

• Presented a generalized theory for rotational diffusion of anisotropic, shape-changing particles in liquid crystals.
• Demonstrated the integration of shape-transition dynamics (Markovian process) with rotational diffusion.
• Analyzed the influence of shape transitions on key correlation functions relevant to experiments.
• The model successfully accounts for flexibility in particle dynamics.

Conclusions:

• The new theory extends rotational diffusion to non-rigid particles in liquid crystals.
• Shape transitions significantly impact particle dynamics and spectroscopic observables.
• This model offers a more realistic approach for analyzing flexible molecules in liquid crystalline environments.
• The findings are crucial for interpreting experimental results in soft matter physics and spectroscopy.