Modulating Coalescence Timing of Liquid Marbles via Wettability Adaptation.

Area of Science:

• Materials Science
• Surface Chemistry
• Fluid Dynamics

Background:

• Droplet coalescence is crucial in nature and industry.
• Liquid marbles (LMs) prevent premature coalescence via particle layers.
• Controlling LM coalescence timing without external stimuli is challenging.

Purpose of the Study:

• To develop liquid marbles with preprogrammed, stimulus-free coalescence timing.
• To enable fine-tuning and cascade control of droplet coalescence.

Main Methods:

• Designing particles with wettable cores and flexible molecular chains of varying lengths.
• Investigating time-dependent wettability changes of the particle layer.
• Modulating LM coalescence timing by adjusting particle properties.

Main Results:

• Achieved preprogrammed coalescence timing for LMs ranging from 2 to 45 minutes without external stimuli.
• Demonstrated fine-tuning of coalescence time with minute-level resolution.
• Enabled cascade droplet coalescence using LMs with different adaptation times.

Conclusions:

• Introduced a novel method for preprogramming LM coalescence timing.
• Highlighted the potential for precise droplet manipulation and advanced applications.
• Established a new route for controlling droplet coalescence through particle design.