Formation of hybrid poly(styrene-co-maleic anhydride)-silica microcapsules.

Judith Van Wijk,Bert Klumperman,Jan Meuldijk,Nedine Van Deventer,Elrika Harmzen

doi:10.1039/c4tb00473f

Abstract

In this contribution we report the synthesis of hybrid poly(styrene-co-maleic anhydride)-SiO2 microcapsules by cross-linking of the stabilizing particles of an inverse Pickering emulsion droplet at the interface. This was achieved by the ring-opening aminolysis reaction of the maleic anhydride residue of poly(St-co-MAh) with amine-functionalized silica particles that stabilized the Pickering emulsion. The cross-linking reaction is clearly shown by labeling the polymer with a green dye and the silica particles with a red dye, followed by confocal fluorescence microscopy analysis. Because poly(St-co-MAh) is a versatile polymer that can react with different other polymers, this opens the possibility of producing microcapsules with versatile properties. Encapsulation of delicate matter, e.g., live cells or enzymes, might be suitable as a result of the straightforward synthesis method.

Highlights

In view of different controlled release applications for microcapsules, the synthesis of microcapsules has gained increased attention over the past decade, e.g., in the food industry or in the drug industry.[1,2,3,4] In the process of microencapsulation, typically a solid shell is formed around a micrometer-sized droplet
We report the facile synthesis of hybrid poly(St-co-MAh)–SiO2 microcapsules by cross-linking of the stabilizing particles of an inverse Pickering emulsion droplet, see Fig. 1
The main advantages of the synthesis procedure described above, e.g. Pickering emulsion polymerization, to produce microcapsules[21] is rstly that the core is not contaminated in the process of capsule formation and secondly that the polymer is pre-synthesized before addition, which allows independent control of the polymer properties

Summary

Introduction

In view of different controlled release applications for microcapsules, the synthesis of microcapsules has gained increased attention over the past decade, e.g., in the food industry or in the drug industry.[1,2,3,4] In the process of microencapsulation, typically a solid shell is formed around a micrometer-sized droplet. The shell material should be semi-permeable and should possess a certain strength and toughness, so that it does not break. This strength is among others necessary upon exposure to external forces, e.g., during re-dispersion of the capsules in a different medium. A very useful feature of the particles that stabilize the Pickering emulsion is that they should be easy to chemically modify. This will make it straightforward to tune the hydrophobicity and to make the

Methods

Results

Conclusion