ABSTRACT
Stimuli-responsive polymers are polymers with the capability of responding to several physical and chemical environmental stimuli. In many of the release profiles, burst release is observed as the initial rapid release of high concentrations. In agriculture, as an important part of fertilizer management, tunable release systems are used extensively to ensure the maintenance of critical levels of fertilizers for long periods of time in fragile weather conditions. The chapter discusses the most widely used stimuli-responsive polymers, their usage in controlled delivery applications, and their release kinetics. Type of stimuli-responsive polymers commonly used in tunable release studies is the pH-responsive polymers. Light responsive polymers are widely used in controlled release studies where the release of the payload is activated by light. These polymers undergo structural changes when exposed to electromagnetic radiation. The release experiments were performed in metalloproteinase solution and phosphate buffer solution separately, and UV irradiation was applied to stimulate the release from the multilayer microcapsules.
