Polyelectrolyte Microcapsules: On the Formation and Possibilities of Regulating Multilayer Structures

— In this review, the principles of the formation of polyelectrolyte microcapsules by the layer-by-layer assembly method have been considered, the intermolecular interactions that take part in the systems have been described, and the factors that affect the parameters of the resulting structures have been listed. Works devoted to tuning the internal structure of polyelectrolyte shells by means of variations in environmental conditions have been presented, in particular, the effect of temperature on polyelectrolyte shells of various compositions has been considered. Examples of changing the permeability of the shells, as well as imparting desired optical properties to the capsules by incorporating dyes and nanoparticles into polyelectrolyte multilayers have been presented. Possible approaches to remote control of shell permeability under the action of external physical stimuli, such as laser and microwave radiations and a low-frequency magnetic field, have been described. One of the sections of the review has been devoted to the methods of encapsulating emulsion droplets via layer-by-layer deposition of polyelectrolytes.