Frustrated crystallization kinetics in marginally mismatched binary self-assembly driven by depletion interactions

Area of Science:

• Colloidal science
• Materials science
• Soft matter physics

Background:

• Colloidal particles are used to create artificial crystals.
• Binary mixtures of particles can lead to complex assembly behaviors.

Purpose of the Study:

• To investigate the impact of impurity particles on two-dimensional colloidal crystal assembly.
• To understand the mechanisms behind disordered assembly in binary mixtures.

Main Methods:

• Experimental observation of colloidal particle assembly.
• Molecular dynamics simulations to analyze energy states and predict assembly behavior.

Main Results:

• Increasing impurity fraction reduces orientational order in colloidal assemblies (up to 18% reduction).
• Binary mixtures exhibit slower growth rates and arrested dynamics compared to monodisperse suspensions.
• Simulations predict compromised translational order but sustained orientational order for size ratios up to 0.88.

Conclusions:

• Disordered assemblies in binary mixtures result from frustration in assembly kinetics.
• Marginal size mismatch between particles drives kinetic frustration, not topological issues.