Elemental Sulfur-Stabilized Liquid Marbles: Properties and Applications.

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Nanotechnology

Background:

• Liquid marbles (LMs) are microcontainers with unique properties, but their stability and shape control remain challenging.
• Sulfur (S8) has potential as a stabilizing agent due to its unique chemical and physical properties.

Purpose of the Study:

• To develop and characterize novel sulfur-stabilized liquid marbles (SLMs).
• To investigate the influence of preparation parameters on SLM properties like deformability, stability, and lifetime.
• To demonstrate the potential applications of SLMs as versatile micro-platforms.

Main Methods:

• Preparation of SLMs by rolling water droplets on a sulfur powder bed.
• Investigation of rolling time and droplet volume effects on SLM deformability and mechanical stability.
• Assessment of SLM lifetime in aqueous and aqueous-organic systems.
• Demonstration of applications including photocatalytic microreactors, electrochemical microcells, and Pickering-like emulsions.

Main Results:

• Sulfur-stabilized liquid marbles were successfully prepared, exhibiting shape-designable characteristics due to a surface gel layer.
• Deformability was tunable by pH, enabling use as microreservoirs for aqueous solutions.
• Immersion in organic liquids significantly enhanced SLM lifetime, allowing long-term survival in biphasic systems.
• SLMs were successfully applied as microreactors, microcells, and in forming monodisperse emulsions.

Conclusions:

• Sulfur-stabilized liquid marbles represent a robust and versatile micro-platform with tunable properties.
• Their enhanced stability in organic media and pH-dependent deformability open avenues for advanced microfluidic applications.
• SLMs show significant promise for use in microreactors, electrochemical devices, and emulsion technologies.