Impact of drops of a nanoparticle dispersion in a viscoelastic liquid

The evaluation of nanoparticle dispersion within viscoelastic fluids upon impact on hydrophobic and hydrophilic surfaces is conducted using the Euler-Lagrangian technique. The volume-of-fluid approach is employed in conjunction with the Lagrangian method to model the transport of nanoparticles in a three-phase system (particles-air-viscoelastic fluid). The assessment of nanoparticle dispersion was conducted over a range of Peclet numbers and contact angles (theta = 30 degrees and 120 degrees) in three-dimensional (3D) space using the mean square displacement method. The findings suggest that the dispersion of nanoparticles is mainly influenced by normal stress. During droplet impact, nanoparticles exhibit non-Fickian superdiffusive behaviour due to the viscoelastic fluid's non-Gaussian distribution of velocity and stresses (normal and shear) fields. The wettability of the fluid with solid surfaces substantially affected the dispersion of nanoparticles in the viscoelastic fluid.