Hydrogels: Temperature‐Sensitive Hydrogel‐Particle Films from Evaporating Drops (Adv. Mater. Interfaces 16/2015)

Most drying colloidal drops produce a useless stain. In article 1500371, T. Still and co-workers show how a simple one-step drying process can be utilized to prepare colloidal hydrogel films that consist of cross-linked micron-size poly(N-isopropyl acrylamide) (PNIPAM) particles. These colloidal hydrogel particles have the unique ability to change their size with temperature. Thus, the PNIPAM films produced by drying drops reversibly change their size as well as their mechanical and optical properties as a function of temperature. Ultimately, these films present new materials with adjustable porosity, size, strength and light transmission.