Emergence of temperature-dependent and reversible color-changing properties by the stabilization of layered polydiacetylene through intercalation

Abstract

The stimuli-responsive color-changing properties of functional polymers are applied to the development of sensing and imaging devices. Tuning the stimuli responsivity is required for a wide range of applications. Polydiacetylene (PDA) derivatives show color changes with the application of external stimuli, such as heat and mechanical stress. Our group has focused on the layered crystal structure of PDA and its intercalation chemistry. The original layered PDA shows an irreversible color transition from blue to red upon heating to the threshold temperature. Here, we found that alkyldiamine-intercalated PDA possessed different color-changing properties, such as a higher color transition temperature and a temperature-dependent and reversible color change, than the original PDA. As the alkyl-chain length increased, the color-changing behavior gradually converted from the irreversible color transition type to the reversible temperature-dependent one. Since the intercalated diamine had a stabilizing effect on the layered structure, the stimuli responsivity varied according to the type of diamine. The results suggest that the stimuli-responsive color-changing properties of layered PDA can be finely and systematically tuned by the intercalation of organic guests. Polydiacetylene (PDA) derivatives exhibit color change with application of external stimuli, such as heating and mechanical stress. The original layered PDA shows the irreversible color transition from blue to red with heating at the threshold temperature. Here we found that the alkyldiamine-intercalated PDA induced the different color-change properties, such as the raise of the color-transition temperature, the temperature-dependent color-change, and the reversible color change. The intercalated diamines have the stabilization effect of the layered polymer. The stimuli-responsive color-change properties can be tuned by the intercalated organic guests.