Microfluidic Vaterite Synthesis: Approaching the Nanoscale Particles.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Continuous synthesis of calcium carbonate (CaCO3) nanoparticles presents challenges in controlling particle characteristics.
• Microfluidic technology offers a potential solution for precise control over nanoparticle formation.

Purpose of the Study:

• To explore one-phase and two-phase synthesis methods for CaCO3 nanoparticles using microfluidic technology.
• To evaluate the efficiency of different synthesis approaches in controlling particle size, morphology, and polymorph composition.

Main Methods:

• Utilized a custom microfluidic chip for CaCO3 nanoparticle synthesis.
• Employed scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and small-angle scattering (SAS) for characterization.
• Investigated both one-phase and two-phase synthesis strategies within microfluidic systems.

Main Results:

• The two-phase synthesis system, particularly within emulsion microreactors, demonstrated superior control over nanoparticle size compared to the one-phase approach.
• Achieved CaCO3 nanoparticles with approximately 50 nm size and high vaterite phase content (86-99%).
• Provided insights into particle size evolution during the transition between one-phase and two-phase synthesis.

Conclusions:

• The two-phase microfluidic method is highly effective for continuous, controlled synthesis of vaterite CaCO3 nanoparticles.
• The developed method offers scalability and the potential for diverse industrial applications requiring specific CaCO3 polymorphs and sizes.