(236a) Capillary-Based Microfluidic Reactors for the Production of Size-Controlled Functional Polymer Particles

We report on the use of microfluidic devices for the synthesis of monodisperse and size-controlled polymer particles (CV<5%), either beads or capsules, in the size range of tens to several hundred of microns.

The emulsification of the monomer phase is achieved in capillary-based microreactors without any surfactant or surface treatment. Polymer beads are obtained after UV irradiation while polymer capsules are directly generated in the microfluidic device through an interfacial polycondensation reaction.

A preliminary study has shown that in the dripping regime the variation of particle diameter with respect to operating parameters (flow rates and viscosities of the dispersed and continuous phases) is fairly well described by an empirical relationship between two dimensionless numbers, the normalized particle diameter and the Capillary numbers ratio [1].

Application of these microsystems concerns O/W or W/O emulsions for the preparation of inorganic-organic hybrid beads as well as hollow and doped capsules. By confining the particles in the microsystem, we have also successfully prepared polymer beads necklaces [2] with different arrangements.

[1] C. Serra, N. Berton, M. Bouquey, L. Prat and G. Hadziioannou, Langmuir, 23 (14) (2007) 7745-7750.

[2] M. Bouquey, C. Serra, N. Berton, L. Prat and G. Hadziioannou, Chem. Eng. J. (In press, doi:10.1016/j.cej.2007.07.043).