Thermosensitive water-soluble copolymers with doubly responsive reversibly interacting entities

The precise control of the formation of stimuli-sensitive sequences (block or graft) as part of copolymer architectures is fascinating because of the remarkable phase behavior of their aqueous solutions. One of the most interesting solution properties of amphiphilic water-soluble copolymers is their ability to self-assemble into micelles, lamellar aggregate, vesicles and hydrogels. In this review we discuss the combinations of thermosensitive properties with other types of sensitivity: i.e. to pH, light, magnetic field, solvent quality, etc., and their effects on the reversible self-assembly in aqueous copolymer solutions or on the hydrogel organization. For this purpose we describe thermosensitive polymers as well as methods for their controlled synthesis. The development of multi-functional building blocks imprinted into one macromolecule will help us to obtain controllable morphologies at the nanometer scale. Obviously, the multi-sensitive copolymer systems represent an essential part of supramolecular polymer chemistry where the environment can have a large effect on the degree of interaction between the individual components in the material. (C) 2007 Elsevier Ltd. All rights reserved.