Double diffusion for the programmable spatiotemporal patterning of multi-domain supramolecular gels

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Soft Matter Physics

Background:

• Precise spatial control over self-assembly is crucial for creating complex functional materials.
• Low-molecular-weight gelators (LMWGs) offer tunable properties for constructing ordered structures.
• Developing methods for fabricating multi-component patterned gels remains a challenge.

Purpose of the Study:

• To introduce a novel double diffusion method for programming spatial patterns in multi-component gels.
• To investigate the influence of gelator type and acid strength on pattern formation and nanoscale structure.
• To demonstrate the ability to control the shape and dimensions of self-assembled gel patterns.

Main Methods:

• Utilized pH-responsive DBS-CO2H and thermally-responsive DBS-CONHNH2 (1,3:2,4-dibenzylidenesorbitol based) LMWGs.
• Employed a double diffusion technique where soluble components diffuse into a pre-formed gel matrix.
• Varied acid strength (strong vs. weak) to control gelation kinetics and resulting nanoscale order.

Main Results:

• Successfully created patterned gel-in-gel objects with well-defined shapes and dimensions.
• Demonstrated that strong acids yield faster kinetics, smaller objects, and less nanoscale order.
• Showed that weak acids result in slower kinetics, larger objects, and more homogeneous nanoscale structures.
• Confirmed that pattern shape is programmable by reservoir geometry and influenced by assembly kinetics.

Conclusions:

• The double diffusion approach provides spatiotemporal control for programming patterned gels.
• Acid choice dictates gelation kinetics, influencing both macroscale object dimensions and nanoscale structural homogeneity.
• This methodology offers a simple yet effective route to emergent patterning in multi-component soft materials.