Densely Cross-Linked Polysiloxane Nanogels

Nanogels can be called the new old§ objects of polymer chemistry. New because we have formulated the criteria for the assignment of objects to this group within the macromolecule-particle concept and developed the methods for their directed and controlled synthesis. Old because the application of these criteria to the earlier known systems allow us to surely classify them as nanogels. It is shown that this classification per se provides insight into the organization of their molecular structures and enables directed modification. This means a transition from the empirical control of the properties to molecular design. The current review presents a brief historical overview of densely cross-linked nanogels and their main synthetic routes and highlights the principles and approaches to the control of their structures and molecular-mass characteristics, application scope, and prospects for further development.