New Dendritic Polydiacetylene Sensor with Good Reversible Thermochromic Ability in Aqueous Solution and Solid Film

Thermal responsive polydiacetylene derived from PAMAM dendrimer (PDA-G<sub>0</sub>) was synthesized. Unlike the ethylenediamine substituted PDA (PDA-NH<sub>2</sub>) solution, the prepared PDA-G<sub>0</sub> vesicle solution showed reversible thermochromism property when temperature varied from 20 to 90 °C, which is due to the formation of an internal hydrogen bond in amide groups. Furthermore, PDA-G<sub>0</sub>/PMMA film with excellent stability was obtained by a mixed-drying method, which could be stored for a long time without denaturation. After polymerization by UV irradiation, it displayed much better reversible thermochromic ability and the responded temperature range became wider, from 20 to 110 °C.