Development of a New Technique to Generate Microcapsules from the Breakup of Non-Newtonian Highly Viscous Fluid Jets

A new method to produce microcapsules ranging from 300 to 700 mu m based on the droplets formation from non-newtonian high viscous liquids has been developed, characterized, and modeled. The technique involves the generation of a continuous high viscous solution jet, which is destabilized by means of a controlled vibration, breaking into droplets that undergo stabilization through a gelling process. Finally, the application of the wave-mechanisms-based theory to obtain a set of equations for the fitting of experimental data is assessed, as a first approximation for a better knowledge of the process. To find the fitting equations, the influence on the microcapsules size is studied through two-dimensionless groups, the Ohnesorge and the Weber numbers, involving the liquid viscosity and flow, respectively, and determining their exponential dependences. Further coefficients are obtained by least-squares fit of the experimental data. (C) 2011 American Institute of Chemical Engineers AIChE J, 57: 3436-3447, 2011