Microfluidic synthesis of colloidal silica.

Area of Science:

• Chemical Engineering
• Materials Science
• Nanotechnology

Background:

• Microfluidic reactors enable precise control over chemical synthesis.
• Colloidal silica particles have diverse applications in materials science and industry.
• Controlling particle size distribution is crucial for material properties.

Purpose of the Study:

• To design, fabricate, and operate microfluidic reactors for colloidal silica synthesis.
• To compare the performance of laminar flow and segmented flow reactors.
• To analyze the impact of flow conditions on particle size and distribution.

Main Methods:

• Fabrication and operation of two microfluidic reactor types: laminar and segmented flow.
• Systematic variation of linear flow velocity and mean residence time.
• Analysis of synthesized silica particle size and size distribution using microscopy or dynamic light scattering.

Main Results:

• Laminar flow reactors exhibited wider particle size distributions at higher velocities due to axial dispersion.
• Segmented flow reactors, utilizing gas bubbles to create liquid plugs, enhanced mixing.
• Internal recirculation in segmented flow reactors mitigated axial dispersion, resulting in narrow silica nanoparticle size distributions.

Conclusions:

• Segmented flow microfluidic reactors provide superior control over colloidal silica synthesis compared to laminar flow reactors.
• Optimized mixing in segmented flow reactors is key to achieving monodisperse nanoparticle production.
• Microfluidic technology offers a promising platform for scalable and controlled nanoparticle manufacturing.