pH- and Salt-Responsive Pickering Polymer Emulsion for Controllable Release of Drag Reducers

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Traditional switching emulsion drag reducers face limitations due to single stimulus sources, restricting their release window and efficiency.
• Enhancing responsiveness and stability is crucial for developing advanced drag reduction technologies.

Purpose of the Study:

• To design and synthesize multiresponsive switchable emulsion drag reducers with improved release characteristics.
• To leverage nanoparticle designability and interfacial stability for controlled drag reducer release.

Main Methods:

• Synthesized pH-responsive metal-organic frameworks (MOFs) utilizing imine bond sensitivity and N-metal ion complexation.
• Constructed a nanoparticle (SiO2-NH2@DF-DAP) with dual pH and salt responsiveness to stabilize Pickering emulsions.
• Prepared and characterized the switching Pickering emulsion drag reducer, assessing its stability and release kinetics.

Main Results:

• The switching Pickering emulsion drag reducer demonstrated remarkable storage stability for over 45 days due to a rigid multilayer interfacial film formed by nanoparticles.
• Complete release of the drag reducer was achieved in 20 seconds under combined pH (4) and salt (70 mM MgCl2) stimuli.
• A significant drag reduction rate of 65% was observed at a low concentration of 0.05 wt %.

Conclusions:

• Developed a novel, stable, and recyclable multiresponsive switchable Pickering emulsion drag reducer.
• The dual pH and salt responsiveness enables rapid and efficient release, overcoming limitations of traditional systems.
• This work provides new strategies for designing efficient drag reducers with tunable release profiles.