Dissipative particle dynamics simulation study on vesicles self-assembled from amphiphilic hyperbranched multiarm...

Area of Science:

• Polymer Science
• Computational Chemistry
• Materials Science

Background:

• Hyperbranched multiarm copolymers (HMCs) are promising precursors for self-assembly into complex supramolecular structures.
• Experimental studies have demonstrated the formation of various structures from HMCs, but theoretical understanding of their self-assembly mechanisms remains limited.

Purpose of the Study:

• To elucidate the self-assembly mechanisms and dynamics of amphiphilic HMCs into normal or reverse vesicles using computational simulations.
• To provide a detailed theoretical insight into the formation pathways of HMC-based vesicles.

Main Methods:

• Dissipative Particle Dynamics (DPD) simulations were employed to model the self-assembly process of amphiphilic HMCs.
• The simulations tracked the evolution from individual copolymers to stable vesicular structures.

Main Results:

• The self-assembly process was observed to proceed through distinct stages: unimolecular micelles, spherical micelles, membrane-like micelles, small vesicles, and finally large, stable vesicles.
• Membrane formation occurs via micelle aggregation and lateral fusion, followed by bending and closure to form vesicles.
• Bilayer or monolayer packing and microphase separation within the vesicles were also characterized.

Conclusions:

• DPD simulations successfully revealed the multi-step mechanism and dynamics of HMC self-assembly into vesicles.
• The study provides unprecedented details on vesicle formation, complementing experimental observations and advancing the understanding of HMC self-assembly.