Programmable Inter-Droplet Communication by Polymer-Gated Ion Transport Through Nanopore Lattices

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Mesoporous platforms facilitate fluid transport due to hydrophilicity and capillary pressure.
• Controlling ion transport is crucial for developing advanced fluidic systems and droplet communication.

Purpose of the Study:

• Investigate nanopore-driven ion transport control via mesoporous surfaces.
• Tailor droplet communication using polyelectrolyte barriers on silica.
• Explore ion-specific interactions and their impact on fluid dynamics.

Main Methods:

• Utilized mesoporous silica thin films with integrated polyelectrolyte (PEL) barriers fabricated by direct-laser-writing and SI-PET-RAFT polymerization.
• Studied droplet communication using aqueous salt solutions (BaCl2, MgSO4, MgCl2, NaCl).
• Analyzed permselective transport-regulated barrier breakthrough times and imbibition dynamics.

Main Results:

• Tuning PEL barrier width achieved tunable ion-selective flow regulation to complete fluid retention.
• Observed ion-specific interactions leading to distinct imbibition dynamics (advancing, hindered, oscillating).
• Demonstrated control of chemical events like precipitation by droplet localization relative to the barrier.

Conclusions:

• Polyelectrolyte barriers effectively regulate ion transport and fluid imbibition in mesoporous systems.
• Insights enable the development of compartmentalized and reconfigurable fluidic communication systems.
• Provides new tools for designing advanced nanostructured coatings for fluid management.