Biocatalytic Feedback-Controlled Non-Newtonian Fluids.

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Non-Newtonian fluids are essential in various applications.
• Controlling fluid rheology dynamically remains a challenge.

Purpose of the Study:

• To develop an intelligent fluidic system with switchable non-Newtonian properties.
• To integrate an autocatalytic enzyme reaction for feedback-controlled rheology.

Main Methods:

• Engineering associative polyelectrolytes with balanced charge density and hydrophobic effects.
• Utilizing the urea-urease clock reaction for pH-induced rheological transitions.
• Demonstrating tunable non-Newtonian states (shear thickening/thinning) via chemical fuel supply.

Main Results:

• Achieved distinct shear thickening (low pH) and shear thinning (high pH) behaviors in polymer solutions.
• Successfully programmed pH changes using an enzyme reaction to control viscoelastic properties.
• Demonstrated tunable lifetimes for the non-Newtonian states.

Conclusions:

• An intelligent fluid system capable of switching between two non-Newtonian states was successfully created.
• The system leverages chemical energy to manipulate physical, nonequilibrium fluid properties.
• This work offers a novel approach for designing responsive materials and fluidic devices.