Nanoparticle de-agglomeration in viscous fluids using different high shear mixer geometries

In the present work, the effect of batch high shear mixer (HSM) geometries is studied on nanoparticles deagglomeration and power draw in water and aqueous glycerol solutions. The kinetics and mechanism of cluster break-up are investigated for disintegrated (less number of larger stator holes), and mesh (higher number of smaller stator holes) heads at different rotor speeds. Mesh head geometry is found to be more efficient for fines generation than disintegrated head. A bi-modal particle size distribution and erosion as dominant break-up mechanism is found. The size of the smallest fines is found to be ≈30 nm for mesh head and ≈50 nm for the disintegrated head. Z-average ranges from 180 to 310 nm for given operating and process conditions. The power draw is more in mesh head and increased with an increase in viscosity. Further, power draw increased with an increase in viscosity of continuous media and rotor speed.