Encapsulation of liquid cores by layer-by-layer adsorption of polyelectrolytes

The aim of this work was to develop the method of preparation of loaded, submicron nanocapsules based on the liquid core encapsulation by polyelectrolyte (PE) multilayer adsorption. The procedure of PE adsorption on the emulsion droplets requires a specific selection of surfactants, which have good properties as emulsifiers and provide a stable surface charge for sequential adsorption of PE without losing stability of emulsion. Using AOT as emulsifier this study obtained droplets, stabilized by AOT/PDADMAC surface complexes. These positively charged liquid cores were then modified by sequential adsorption of polyelectrolytes to obtain nanocapsules with the average size of 200 nm, with various combinations of polyelectrolytes (PDADMAC, CHIT, PAH, PSS, ALG). This study demonstrated the formation of consecutive layers of PE shells by measuring zeta potential of capsules after adsorption of each layer. It visualized the cores by dissolving fluorescent dye Coumarine6 in oil phase and multilayer shells by using FITC labelled polycation.