Polyethylene nano crystalsomes formed at a curved liquid/liquid interface

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Crystallization is typically incompatible with nanoscale curved surfaces due to symmetry constraints.
• Developing methods for creating crystalline nanostructures on curved interfaces remains a challenge.

Purpose of the Study:

• To report the formation of single-crystal-like, nanosized polyethylene (PE) capsules (crystalsomes) using a miniemulsion solution crystallization method.
• To investigate the formation mechanism, structure, and properties of these novel nanostructures.

Main Methods:

• Miniemulsion formation using PE organic solution and sodium dodecyl sulfate surfactant at elevated temperatures.
• Stepwise cooling for controlled crystallization at the curved liquid/liquid interface.
• Characterization using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and atomic force spectroscopy.

Main Results:

• Successfully synthesized hollow, nanosized PE crystalline capsules (crystalsomes) with single-crystal-like characteristics.
• Observed reduced crystallinity and crystallite size due to the incommensurateness between the nanocurved interface and PE crystalline packing.
• Demonstrated the formation of hierarchical porous PE crystalsomes via quenching, coupling PE crystallization with liquid/liquid phase separation.

Conclusions:

• Controlled crystallization at curved interfaces enables the formation of unique single-crystal-like nanostructures (crystalsomes).
• The incommensurateness influences the crystalline properties of the resulting nanostructures.
• PE crystalsomes represent a novel nanostructure with potential applications as nanodrug carriers and ultrasound contrast agents.