PMMA/PMMA core-shell particles with ellipsoidal, fluorescent cores: accessing rotational dynamics

Area of Science:

• Colloid and Surface Science
• Polymer Chemistry
• Materials Science

Background:

• Nonaqueous polymer dispersions, particularly polymethyl methacrylate (PMMA), are crucial in colloid research.
• PMMA particles serve as model systems for investigating phenomena like glassy dynamics and crystal nucleation.
• Existing research predominantly focuses on spherical particles, limiting investigations to translational motion.

Purpose of the Study:

• Introduce a new class of core-shell particles designed as rotational probes.
• Enable the study of rotational dynamics in colloidal systems.
• Develop shape-tunable colloids with fluorescent anisotropic cores and nonfluorescent PMMA shells.

Main Methods:

• Synthesis of fluorescent, photo-cross-linkable PMMA colloids.
• Thermomechanical elongation and photo-cross-linking to create ellipsoidal cores.
• Coating of cross-linked cores with nonfluorescent PMMA shells.
• Solvent swelling technique to tune particle shape from anisotropic to spherical.
• Morphological characterization using fluorescence microscopy.

Main Results:

• Successful fabrication of core-shell particles with tunable shapes.
• Creation of PMMA spheres with ellipsoidal, fluorescent centers.
• Demonstration of morphological control over particle shape.
• Validation of fluorescence microscopy for particle characterization.

Conclusions:

• The developed core-shell particles are effective rotational probes for colloidal systems.
• The synthesis method allows for tunable particle anisotropy and shape.
• These novel colloids open new avenues for studying rotational dynamics in complex fluids.