ABSTRACT
Surface-attached hydrogel films consisting of water-swollen polymer networks possess a large number of specific and highly attractive properties, which render them valuable materials essential for a large range of applications. The present chapter focuses on such anchored polymer network layers (in distinction to macroscopic bulk hydrogel systems, microgels, or polymer brush layers) and describes their chemical nature, nanoscopic and mesoscopic structure, and particular properties and discusses examples of consequential applications. Specifically, responsive hydrogel systems, which can change their physical state upon stimulation by changes in the environmental parameters, have found large interest as “smart” materials that provide a complex behavior to hydrogel-based devices.
