New sight at the organization of layers of multilayer polyelectrolyte microcapsules

Abstract

In this work, the mutual arrangement of polyelectrolytes of multilayer polyelectrolyte microcapsules (with layers-[PAH/PSS]₃PAH) by determination of the dissociation level of polyallylamine (PAH) from the surface of a polyelectrolyte microcapsules (PMC) of various types was studied: PMC with a dissolved CaCO₃ core after preparation, PMC with an undissolved CaCO₃ core and PMC with an encapsulated protein. It was concluded that the polyelectrolyte layers are mixed in the entire shell of the capsules with a dissolved CaCO₃ core. In the case of the PMC with an undissolved CaCO₃ core, such mixing of polyelectrolyte layers does not occur. That fact allows us to conclude that the mixing of polyelectrolytes layers mixing at the stage of dissolution of CaCO₃ core. The PMC with encapsulated protein has partial mixing of polyelectrolytes layers. That phenomenon may be due to the fact that seven-layered protein-containing microcapsules already have a dense and well-formed shell. The obtained data correlate with the data on the study of the surface charge of microcapsules.

Figure 1

Electron microscopy of ultrathin slice of protein-free PMC (A) and PMC (B) containing protein.

Figure 2

Stages of polyelectrolyte microcapsules preparation.

Figure 3

Dissociation of polyelectrolyte layers of microcapsules contained CaCO3, incubated in 2 M NaCl solution.

Figure 4

Dissociation of polyelectrolyte layers of microcapsules, which contained interpolyelectrolyte complex, incubated in 2 M NaCl solution.

Figure 5

Dissociation of polyelectrolyte layers of microcapsules contained protein, incubated in 2 M NaCl solution.