The situation of liquid drop bag-stamen breakup in a continuous air jet flow is investigated by a high speed camera. Test liquids include water, ethanol, and various glycerol mixtures. First, the morphology of bag-stamen breakup is observed and analyzed. The bag-stamen breakup range is found to be in good agreement with the model obtained by Rayleigh-Taylor instability. Then the disk and stamen deformation properties, the fragment average size, and size distribution of ring and stamen are researched in detail, respectively.

According to recent research reports, addition of small amounts of a secondary fluid to a suspension could dramatically increase viscosity of suspension. Results of this study indicate another interesting behavior that the secondary fluid could form a thin hydrophobic membrane around particle surface and significantly decrease the viscosity and yield stress of the suspension. To enhance the surface hydrophobicity, hydrophobic nanoparticles (nano-CaCO₃) were added to the hydrophobic membrane of particles to improve the surface roughness and to generate composite particles having a hierarchical structure similar to the micromorphology of lotus leaf. This composite particle has a higher contact angle and the suspension of composite particles has a lower viscosity and a lower yield stress.