Tuning the shape anisotropy of loosely bound colloid-like ionic clusters in solution

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Solution Chemistry

Background:

• Dynamic self-assembly is crucial for creating complex structures from simple building blocks.
• Ionic clusters, or ionoids, represent a novel class of self-assembled materials in solution.
• Understanding the factors governing ionoid formation is key to controlling their properties.

Purpose of the Study:

• To investigate the impact of ionic ratios on the self-assembly of ionoids.
• To characterize the dynamic formation and evolution of these ionic clusters.
• To establish methods for controlling ionoid size, shape, and stability.

Main Methods:

• Dynamic Light Scattering (DLS) for size and monodispersity analysis.
• Continuous Wave Electron Paramagnetic Resonance (CW EPR) spectroscopy for structural insights.
• Systematic variation of ionic ratios to map assembly conditions.

Main Results:

• A specific range of ionic ratios was identified as 'privileged' for ionoid formation.
• Monodisperse, spheroidal ionoids with tunable hydrodynamic radii (6-12 nm) were achieved.
• Adjustable shape anisotropy in the formed ionoids was demonstrated.
• Ionoid Evolution Diagrams (IEDs) were developed to map structural development over time.

Conclusions:

• Ionic ratio is a critical parameter for controlling ionoid self-assembly.
• IEDs provide a framework for understanding the temporal evolution of ionoid structures.
• This work enables the rational design of globular and anisotropic ionic clusters with long-term stability.