Membrane emulsification for the production of suspensions of uniform microcapsules with tunable mechanical properties

A way forward for high throughput fabrication of microcapsules with uniform size and mechanical properties was reported irrespective of the kinetic process of shell assembly. Microcapsules were produced using lab-scale emulsification equipment with a micro-engineered membrane in the size range 10-100 mu m. The shell of the microcapsules was assembled at the water-oil interface by complexation of polyelectrolytes or cross-linking of proteins providing two different kinetic processes. Elasticity of microcapsules was characterized with an automated extensional flow chamber. Process parameters were optimized to obtain suspensions with size variations of 15%. Some strategies were developed to obtain uniform elastic properties according to the kinetics of shell assembly. If kinetics is limited by diffusion, membrane emulsification and shell assembly have to be split into two steps. If kinetics is limited by the quantity of reactants encapsulated in the droplet, variations of elastic properties result only from size variations. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

High throughput fabrication of microcapsules with uniform size and mechanical properties can be achieved using lab-scale emulsification equipment and complex shell assembly methods. By optimizing process parameters and developing strategies, desired elastic properties can be obtained based on the kinetics of shell assembly.