Thermoresponsive Glasses: Temperature-Controlled Rapid Swelling and Deswelling of Silica-Based Sol-Gels

A novel silica sol-gel that swells or shrinks rapidly by changing its hydration state upon temperature variation is described. The swelling–deswelling (see Figure) is reversible and the kinetics of the bulk transition are fast. The effects of preparation technique and structural variation on the thermal shrinkage properties are discussed.