Study on preparation and performance of reversible thermochromic microcapsulation

Using ethyl cellulose, polyethylene, cyclohexane and Span80 to prepare thermochromic microcapsule by oil phase separation method was presented. The wall of microcapsule was made of ethyl cellulose and polyethylene, whereas the core was made of thermochromatic material (CoCl₂·6H₂O). Cyclohexane and Span80 were used as solvent and emulsifier, respectively. The physical properties of microcapsules were investigated using scanning electron microscopy (SEM), biomicroscope and hot stage polarized optical microscopy (HS-POM). And the heat resistance, solvent resistance, chemical stability and polymer compatibility of the thermochromic microencapsules were investigated. Finally, the effects on thermochromism and project performance of the paint in different content of the thermochromic microcapsule were discussed. The results indicate that the mean size of microcapsules is about 4.5 μm, and reversible thermochromic paint has fine performance.