Investigation of reversible self-thermochromism in microencapsulated fluoran-based materials

摘要

In the present study, eight self-thermochromic fluorans (STC1-STC8) were synthesized, and their reversible thermochromic properties were investigated without the use of a color developer. This work demonstrated the role of the phenol group on ring c on the thermochromic reversibility of the fluorans. Furthermore, the two component mixtures that contained fluorans and methyl stearate were used to examine the thermochromic behaviors of the fluorans with steady heating and cooling rates. The thermochromic properties of the fluorans were evaluated using solid-state UV-Vis, reflectance and FT-IR spectroscopic techniques. DFT calculations were conducted to justify the optical behaviors of the fluorans in their spirolactam forms (STC1-STC8) and cationic forms (STC1 +- STC8+). Finally, STC1 was successfully microencapsulated and applied in acrylic fiber to use as thermal indicators.