Stirring-directed pathway selection between 1D nanofibers and multilayer sheet-like assemblies in supramolecular...

Area of Science:

• Supramolecular chemistry
• Materials science
• Chemical engineering

Background:

• Azobenzene derivatives are photo-responsive molecules with potential in self-assembly.
• Controlling the morphology of self-assembled structures is crucial for their applications.
• Kinetically controlled self-assembly often leads to complex product mixtures.

Purpose of the Study:

• To investigate the effect of mechanical stirring on the self-assembly pathway of azobenzene derivatives.
• To achieve selective formation of specific supramolecular architectures.
• To understand how external stimuli can bias self-assembly evolution.

Main Methods:

• Utilized a common azobenzene derivative as the building block.
• Applied continuous mechanical stirring as a persistent input during self-assembly.
• Characterized the resulting supramolecular assemblies using appropriate analytical techniques (e.g., microscopy, spectroscopy).

Main Results:

• Mechanical stirring biased the self-assembly pathway towards multilayer sheet-like assemblies (Agg2).
• The formation of kinetically persistent nanofibers (Agg1) was suppressed under stirring conditions.
• Demonstrated supramolecular pathway selection driven by mechanical force.

Conclusions:

• Stirring provides a viable method for directing the self-assembly of azobenzene derivatives.
• Mechanical input can overcome kinetic traps and promote the evolution towards thermodynamically or kinetically favored structures.
• This work offers a strategy for controlling the morphology of functional soft materials.