Microencapsulation is a process by which individual particles of an active agent can be stored within a shell, surrounded or coated with a continuous film of polymeric material to produce particles in the micrometre to millimetre range, for protection and/or later release.
Microencapsulation is the protective technology of encapsulating solid, liquid or gas materials into micro particles with a diameter of 1–1000 μm, and has been widely used in fields of medicine, cosmetics, food, textile and advanced materials (Campos et al., 2013; Dubey et al., 2009). The unique advantage of microencapsulation lies in that the core material is completely coated and isolated from external environment. More importantly, microencapsulation would not affect the properties of core materials, provided that proper shell material and preparing method are chosen. Therefore, microencapsulation is very suitable for improving the stability of thermochromic mixtures. After being encapsulated, the thermal stability and the resistances to leaching, acid and solvent for thermochromic materials would be significantly enhanced, which obviously extends their application fields. As a result, the majority of commercial thermochromic materials are produced in the form of microcapsule powders or microcapsule suspensions.