Bell-shaped sol-gel-sol conversions in pH-responsive worm-based nanostructured fluid.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Colloid Science

Background:

• Designing responsive materials is crucial for advanced applications.
• Controlling self-assembly through external stimuli like pH is a key challenge.
• Non-surface-active components offer unique formulation possibilities.

Purpose of the Study:

• To create a novel pH-switchable worm system using simple, non-surface-active components.
• To investigate the sol-gel-sol transitions induced by pH changes.
• To understand the relationship between pH, structure, and phase behavior.

Main Methods:

• Fabrication of a supramolecular system by mixing N-(3-(dimethylamino)propyl)palmitamide (PMA) and citric acid (HCA) at a 3:1 molar ratio.
• Characterization of the nanostructured fluid's phase behavior under varying pH conditions.
• Analysis of structural transformations using techniques sensitive to aggregate morphology.

Main Results:

• A stable, nanostructured fluid was successfully fabricated.
• The system exhibited reversible bell-shaped sol-gel-sol transitions with sequential pH variation.
• Structural transformations from spheres to worms to no aggregates were observed with changing pH.

Conclusions:

• The simple mixture of PMA and HCA provides a versatile platform for pH-responsive materials.
• The observed transitions demonstrate tunable self-assembly driven by pH.
• This system holds potential for applications requiring controlled viscosity and structure modulation.