pH mediated rheological modulation of chitosan hydrogels

Area of Science:

• Materials Science
• Polymer Chemistry
• Rheology

Background:

• Chitosan (CS) hydrogels are widely utilized due to their pH-responsive nature.
• Understanding the rheological properties of CS hydrogels is crucial for optimizing their applications.
• Limited research exists on how pH variations affect the rheological behavior of CS hydrogels.

Purpose of the Study:

• To investigate the pH-dependent rheological properties of chitosan hydrogels.
• To analyze the impact of acetic acid concentration on CS hydrogel rheology.
• To elucidate the flow behavior, creep recovery, and thixotropy of CS hydrogels under varying pH conditions.

Main Methods:

• Preparation of chitosan hydrogels with varying acetic acid concentrations.
• Rheological characterization including flow behavior, creep recovery, and thixotropy measurements.
• Mathematical modeling (Power Law and Herschel-Bulkley models) to interpret rheological data.

Main Results:

• Chitosan hydrogels demonstrated high elasticity and significant creep recovery, independent of pH.
• Steady flow behavior of CS hydrogels varied considerably with changes in pH.
• Thixotropic properties of the hydrogels were substantially influenced by pH alterations.

Conclusions:

• Chitosan hydrogels exhibit robust elastic properties across different pH levels.
• The pH sensitivity of CS hydrogels is primarily evident in their steady flow and thixotropic characteristics.
• These findings provide valuable insights for tailoring CS hydrogel performance in pH-sensitive applications.