pH and cation-responsive supramolecular gels formed by cyclodextrin amines in DMSO

Area of Science:

• Supramolecular Chemistry
• Materials Science

Background:

• Cyclodextrins are cyclic oligosaccharides with a hydrophobic cavity and hydrophilic exterior.
• Amine modification introduces functional groups that can interact with analytes and influence self-assembly.
• Organogels are liquid-filled polymer networks with potential applications in various fields.

Purpose of the Study:

• To investigate the gelation properties of amine-modified cyclodextrins.
• To determine the responsiveness of these organogels to pH and cations.
• To explore the potential of these materials in stimuli-responsive systems.

Main Methods:

• Synthesis of amine-modified cyclodextrins.
• Solvent screening for organogel formation in dimethyl sulfoxide (DMSO).
• Rheological studies to confirm gel formation and assess mechanical properties.
• UV-Vis spectroscopy and titration methods to evaluate pH and cation responsiveness.

Main Results:

• Amine-modified cyclodextrins successfully formed organogels in DMSO at low molar fractions.
• The organogels exhibited distinct responses to changes in pH, indicating pH-responsiveness.
• The presence of specific cations induced significant changes in the gel state, demonstrating cation-responsiveness.
• The gelation process was found to be reversible upon removal of the stimulus.

Conclusions:

• Amine-modified cyclodextrins are effective building blocks for creating stimuli-responsive organogels.
• These organogels offer a promising platform for applications requiring sensitive detection or controlled release.
• The pH and cation responsiveness of these DMSO-based organogels highlight their versatility in materials science.