Surface-Assisted Self-Assembly of a Hydrogel by Proton Diffusion.

Area of Science:

• Supramolecular chemistry
• Materials science
• Surface chemistry

Background:

• Controlling supramolecular growth at solid surfaces is crucial for developing advanced supramolecular materials.
• Self-assembly of molecules at interfaces offers pathways to novel material structures.
• Benzene-1,3,5-tricarboxamide derivatives are known for their self-assembly properties.

Purpose of the Study:

• To develop a method for controlling supramolecular growth at solid-liquid interfaces.
• To investigate the assembly behavior of a dendritic benzene-1,3,5-tricarboxamide peptide conjugate triggered by a pH jump.
• To enable the creation of structured supramolecular materials via surface-assisted self-assembly.

Main Methods:

• Synthesis of a dendritic benzene-1,3,5-tricarboxamide peptide conjugate.
• Utilizing stopped-flow kinetics and mathematical modeling to study solution-phase assembly dynamics (nucleation, elongation, fragmentation).
• Employing surface-assisted self-assembly driven by controlled proton diffusion from the bulk solution.

Main Results:

• The dendritic conjugate's assembly can be initiated by a pH jump.
• Quantitative understanding of solution-phase assembly kinetics was achieved through modeling.
• Successful surface-assisted self-assembly was demonstrated by controlling proton diffusion rates relative to nucleation lag phase.
• Progressive hydrogel growth outwards from the surface was observed.

Conclusions:

• A novel method for surface-assisted self-assembly of supramolecular materials was established.
• The method is generally applicable to various gelators, allowing for the creation of structured materials.
• Controlled proton diffusion is key to achieving ordered supramolecular growth at interfaces.