Thermochromic microcomposites with extremely high sensitivity to ionizing radiation

The influence of ionizing irradiation on the thermochromic properties of [NH2(C2H5)2]2CuCl4 (DEACC) microcrystals incorporated into a polystyrene matrix was investigated. This composite was found to possess thermochromic properties very similar to those in a bulk crystal although its thermochromic phase transition was shifted toward higher temperatures due to the tensions arising within the interface between the polystyrene matrix and the microcrystal. The similar doses of ionizing radiation cause much more pronounced changes in the thermochromic properties of the microcrystals in comparison with a bulk crystal. The main impact consists in the considerable shift of the phase transition temperature derived from the D(T) hysteresis loops toward lower values that were explained by the breaking of the chemical bonds between the polymer matrix and the microcrystals and the corresponding diminishing of the surface strains. The transformation of the discontinuous phase transition into the continuous one under the influence of irradiation was also discussed.